Patrícia Baptista

This work performs a Life Cycle Analysis to assess the environmental impacts of all stages of a shared e-scooter, based on the use case of Lisbon, Portugal. Results indicate that an e-scooter emits 804 to 1679 g CO2/km, which is justified by its low use rates and reduced life span. Its production accounts for more than 70% of impacts, collection and distribution processes for 6% and vehicle use corresponds to 17%. Increasing the shared e-scooter life expectancy reduces environmental impacts by… Exibir mais

This work performs a Life Cycle Analysis to assess the environmental impacts of all stages of a shared e-scooter, based on the use case of Lisbon, Portugal. Results indicate that an e-scooter emits 804 to 1679 g CO2/km, which is justified by its low use rates and reduced life span. Its production accounts for more than 70% of impacts, collection and distribution processes for 6% and vehicle use corresponds to 17%. Increasing the shared e-scooter life expectancy reduces environmental impacts by 26 to 47%, while increasing the kilometers per day reduces the impacts between 50% to 80%. Also, a less frequent collection of e-scooters would improve the results between 7 and 42%. These results enabled defining specific strategies and policies to guarantee a more sustainable deployment and operation of shared e-scooter systems. Exibir menos

This paper describes the MetaExplorer, a GIS-platform, which gathers trustable energy-related datasets, at municipal level for Portugal, providing a user-friendly georeferenced visualisation tool that can be used to derive statistical models, and support policymaking. Publicly available data was collected and cleaned, divided on five thematic areas: energy demand, buildings, mobility, waste management, and socio-economic, while a visualisation tool was developed to provide the possibility to… Exibir mais

This paper describes the MetaExplorer, a GIS-platform, which gathers trustable energy-related datasets, at municipal level for Portugal, providing a user-friendly georeferenced visualisation tool that can be used to derive statistical models, and support policymaking. Publicly available data was collected and cleaned, divided on five thematic areas: energy demand, buildings, mobility, waste management, and socio-economic, while a visualisation tool was developed to provide the possibility to further explore relations between indicators and support the energy transition at local level, delivering customised analyses with a global perception. Exibir menos

In the paper, we develop such profiles for a class of electric L-category vehicles, which are anticipated to play an increasing future role in urban areas. While such driving cycles exist for regular L-category vehicles, these may not be suitable in the case of electric vehicles, due to their power output limitations. We present a methodology for deriving these new driving cycles, developed from empirically deduced power relationships, before demonstrating their application under different… Exibir mais

In the paper, we develop such profiles for a class of electric L-category vehicles, which are anticipated to play an increasing future role in urban areas. While such driving cycles exist for regular L-category vehicles, these may not be suitable in the case of electric vehicles, due to their power output limitations. We present a methodology for deriving these new driving cycles, developed from empirically deduced power relationships, before demonstrating their application under different assumptions on the terrain and vehicle characteristics. The applications demonstrate the feasibility of the method in developing appropriate driving patterns for alternative real-world contexts. On flat terrain, the adjustments made to cope with the power limitations of L-EV do not introduce significant differences in energy consumption, suggesting that the certification does not require extensive modification. However, when considering road slope, differences of up to 5% in energy use and up to 10% in regenerated energy were observed, showing the importance of the developed method for assessing vehicle performance in real-world driving. Exibir menos

This paper evaluates the potential of Photovoltaic integrated into EV in real-world conditions to assess energy consumption, range and EV's charging frequency for battery and fuel cell powertrain configurations. A simulation model is developed, which estimates the energy production through onboard Photovoltaics, energy consumption, and range under diverse driving profiles for five different vehicle types, ranging from Micro-car, 5 seaters light-duty vehicle, Shuttle and heavy-duty… Exibir mais

This paper evaluates the potential of Photovoltaic integrated into EV in real-world conditions to assess energy consumption, range and EV's charging frequency for battery and fuel cell powertrain configurations. A simulation model is developed, which estimates the energy production through onboard Photovoltaics, energy consumption, and range under diverse driving profiles for five different vehicle types, ranging from Micro-car, 5 seaters light-duty vehicle, Shuttle and heavy-duty vehicles.

The results showed that the range increased with reduced energy consumption and charging frequency with onboard Photovoltaics for battery powertrain configuration. The range improved by 30–50% for Microcar and 30–100% for the 5-seater vehicle with the private driving profile. Simultaneously, for Shuttle, an increase in the range between 5 and 15% is reported. On the contrary, the results indicated the fuel cell powertrain configuration does not present an added value with onboard Photovoltaics. Further analysis showed that the higher irradiance rates improved the operational period of Photovoltaic integrated into EV by 5 more days than standard EV. Finally, the economic analysis revealed that Photovoltaics integrated into EV is profitable, reaching the break-even point on the additional photovoltaics expense before the half-life of the vehicle, which makes the total ownership cost lower than a standard EV for its lifetime. Exibir menos

This paper presents an improved emissions modelling approach (named VSP+M) by combining the vehicle specific power (VSP) with load-regime engine maps for each VSP mode. The new modelling enabled to link tailpipe emissions to vehicle and engine operating conditions, obtained from real driving emission (RDE) tests and on-board diagnosis (OBD) data. The parameters for the sizing of engine maps were optimised by means of Pareto frontiers to solve the trade-off between the minimisation of RMSE and… Exibir mais

This paper presents an improved emissions modelling approach (named VSP+M) by combining the vehicle specific power (VSP) with load-regime engine maps for each VSP mode. The new modelling enabled to link tailpipe emissions to vehicle and engine operating conditions, obtained from real driving emission (RDE) tests and on-board diagnosis (OBD) data. The parameters for the sizing of engine maps were optimised by means of Pareto frontiers to solve the trade-off between the minimisation of RMSE and emission factor errors in urban sections and total RDE trips. The CO2 emission factors errors were reduced up to 63% and 45% for urban and RDE sections, respectively. The NOx emission factor errors were reduced up to 15%, maintaining the same RMSE levels. Optimal engine maps sizing was found for every tested vehicle and for each engine type to be applied in other vehicles. This study demonstrates the potential to address declinations of the conventional VSP model based on engine operation or proxies to those variables by using the proposed approach. Exibir menos

This paper applies an energy systems model to evaluate how shared mobility (ride-hailing and shared autonomous vehicles), public buses, alternative energy sources (electricity and biofuels) and carbon pricing contribute to reduce passenger vehicles CO2 emissions in Rio de Janeiro state, Brazil, from 2016 to 2050. Public buses and carpooled shared mobility increase system capacity, resulting in lower vehicle ownership, energy demand and CO2 emissions, as well as savings per ton of CO2 abated… Exibir mais

This paper applies an energy systems model to evaluate how shared mobility (ride-hailing and shared autonomous vehicles), public buses, alternative energy sources (electricity and biofuels) and carbon pricing contribute to reduce passenger vehicles CO2 emissions in Rio de Janeiro state, Brazil, from 2016 to 2050. Public buses and carpooled shared mobility increase system capacity, resulting in lower vehicle ownership, energy demand and CO2 emissions, as well as savings per ton of CO2 abated (from $3 to $4186). Biofuels reduce CO2 emissions at no increased system cost, while carbon pricing is the most effective policy to reduce CO2 emissions, but it is costlier than the alternatives and results in greater private vehicle use (up to 260%) if the expansion of zero-carbon public transportation remains limited due to technology adoption. The policy that reduces the most emissions (by 84%) combines the expansion of renewable electricity generation and implementation of a CO2 price. Exibir menos

This paper explores the effects of payload, air density, wind, and topography on commercial cargo bicycle energy-use in cities with a focus on six European capitals (Berlin, Paris, Rome, Lisbon, Oslo, and London), and is supported by an empirical model using GPS traces and hourly weather data. The study finds that city hilliness could deplete up to 13-34% of the riders’ energy-use, while wind speed can negatively affect the bikes’ energy-use by up to 12-23%. Air-density effects are small;… Exibir mais

This paper explores the effects of payload, air density, wind, and topography on commercial cargo bicycle energy-use in cities with a focus on six European capitals (Berlin, Paris, Rome, Lisbon, Oslo, and London), and is supported by an empirical model using GPS traces and hourly weather data. The study finds that city hilliness could deplete up to 13-34% of the riders’ energy-use, while wind speed can negatively affect the bikes’ energy-use by up to 12-23%. Air-density effects are small; however, in cold cities like Oslo, they could reduce riders’ energy-use by up to 8% in wintertime. These estimates can enable future studies to assess the operational feasibility of commercial cargo bicycles and help policy makers to promote their use by subsidizing the purchase of batteries to mitigate energy-use differences across cities due to topographic or weather effects. Results reveal that, across the cities in this study, this “ideal battery size” varies from 0.1-0.8 kWh in Berlin to 1.6-2.1 kWh in Lisbon. Exibir menos

This study compares the performance of different vehicle types based on the number of passengers/payloads, powertrain configuration (battery and fuel cell electric configurations), and drive cycles, to assess range and energy consumption. An adequate choice of vehicle segment according to the real passenger occupancy enables the least energy consumption. Vehicle performance in terms of range points to remarkable results for the FCEV (fuel cell electric vehicle) compared to BEV (battery electric… Exibir mais

This study compares the performance of different vehicle types based on the number of passengers/payloads, powertrain configuration (battery and fuel cell electric configurations), and drive cycles, to assess range and energy consumption. An adequate choice of vehicle segment according to the real passenger occupancy enables the least energy consumption. Vehicle performance in terms of range points to remarkable results for the FCEV (fuel cell electric vehicle) compared to BEV (battery electric vehicle), where the former reached an average range of 600 km or more in all different drive cycles, while the latter was only cruising nearly 350 km. Decisively, the cost analysis indicated that FCEV remains the most expensive option with base cost three-fold that of BEV. The FCEV showed notable results with an average operating cost of less than 7 cents/km, where BEV cost more than 10 €/km in addition to the base cost for light-duty vehicles. The cost analysis for a bus and semi-truck showed that with a full payload, FCPT (fuel cell powertrain) would be more economical with an average energy cost of ~1.2 €/km, while with BPT the energy cost is more than 300 €/km. Exibir menos

This paper presents an innovative approach based on real world mobility patterns collected for a sample in the city of Lisbon, Portugal, to assess users’ electric vehicle feasibility by assessing different recharging scenarios, comparing stationary and dynamic recharging scenarios. The results indicate that at least 15 % more drivers would be eligible to own an electric vehicle if wireless charging was available. Moreover, wireless charging reduces the range of battery used, with stationary… Exibir mais

This paper presents an innovative approach based on real world mobility patterns collected for a sample in the city of Lisbon, Portugal, to assess users’ electric vehicle feasibility by assessing different recharging scenarios, comparing stationary and dynamic recharging scenarios. The results indicate that at least 15 % more drivers would be eligible to own an electric vehicle if wireless charging was available. Moreover, wireless charging reduces the range of battery used, with stationary charging requiring circa 3.2 times more battery range. The developed approach confirms that wireless dynamic recharging can significantly change the framework of current electric mobility limitations, reducing range anxiety issues, contributing to redesign electric vehicle battery capacity and overcome barriers in stationary charging deployment and availability. Exibir menos

This work develops an electric vehicle model to study influential parameters such as battery capacity, battery energy density, driving environment (speed and temperature) and driving behaviour (aggressiveness). The developed model, implemented in MATLAB-Simulink, includes 5 sub-systems (vehicle model, motor, battery, regenerative braking and speed profile) and evaluates in 1 Hz drive-cycles state of charge, average energy consumption per km and range.
The model estimates energy consumption… Exibir mais

This work develops an electric vehicle model to study influential parameters such as battery capacity, battery energy density, driving environment (speed and temperature) and driving behaviour (aggressiveness). The developed model, implemented in MATLAB-Simulink, includes 5 sub-systems (vehicle model, motor, battery, regenerative braking and speed profile) and evaluates in 1 Hz drive-cycles state of charge, average energy consumption per km and range.
The model estimates energy consumption and range of electric vehicles with an error less than 2% for seven electric vehicles in Worldwide Harmonized Light Vehicles Test Procedure drive-cycles. The study demonstrated that increasing battery energy capacity by three-fold, range can be increased by 294%, with an increase of vehicle mass by 1.5 kg/Wh. While the change in energy density of the battery from 157 Wh/kg to 224 Wh/kg shows a reduction of 2–4% in energy consumption. Besides, maintaining average speed between 25 and 40 km per hour results in maximum range, whereas aggressive driving has a negative influence and reduces vehicle range. Also, the same vehicle can result in a range difference of 25–35% in northern and southern European countries due to varying atmospheric conditions. Exibir menos

As alternative vehicle technologies gain more importance in the market, this work assesses the possibility of a multi power source vehicle configuration by evaluating the performance of an electric vehicle powered by battery (BEV), fuel cell (FCEV), ultra-capacitor (UC) and combination of the former. A flexible vehicle simulation model was developed in MATLAB-Simulink and vehicle performance was evaluated in various 1 Hz certified cycles, enabling the assessment of light duty and heavy-duty… Exibir mais

As alternative vehicle technologies gain more importance in the market, this work assesses the possibility of a multi power source vehicle configuration by evaluating the performance of an electric vehicle powered by battery (BEV), fuel cell (FCEV), ultra-capacitor (UC) and combination of the former. A flexible vehicle simulation model was developed in MATLAB-Simulink and vehicle performance was evaluated in various 1 Hz certified cycles, enabling the assessment of light duty and heavy-duty vehicles powered by various power sources. The developed model accurately estimates energy consumption and range of passenger vehicle with an average absolute error of less than 4% and 2% for the electric bus. The study showed that BEV has the least energy consumption (23%), followed by FCEV (65%) compared to internal combustion engine (ICE) vehicles in real world conditions. Regarding the combination of energy sources, an increase in range by 10% is estimated when battery is combined with fuel cell, while combining ultra-capacitor with battery enables a lifetime extension of battery life by 10%, with negligible change in range. Combining secondary sources with fuel cell shows a reduction of total fuel cell capacity by 40% for the same operation. Analysis on ultra-capacitor showed negative response with light duty vehicle, while for buses the usage of batteries shows positive results with negative impacts on cost and recharging time. Ultra-capacitors are highly recommended for short-frequent trips with fast recharging and a life of 20 years, while fuel cells as a primary energy source are recommended for the long-range trips in coaches and trucks. Exibir menos

This work studies the competitiveness of different pathways of exporting hydrogen from offshore production plants, with special focus on the offloading to export hydrogen (pure hydrogen or hydrogen carriers) to land. This analysis relies on a techno-economic assessment of these pathways, including the determination of their levelized cost of hydrogen, the net present value and their energy expenditure. Among the studied pathways, the use of pipelines to transport hydrogen presents as the best… Exibir mais

This work studies the competitiveness of different pathways of exporting hydrogen from offshore production plants, with special focus on the offloading to export hydrogen (pure hydrogen or hydrogen carriers) to land. This analysis relies on a techno-economic assessment of these pathways, including the determination of their levelized cost of hydrogen, the net present value and their energy expenditure. Among the studied pathways, the use of pipelines to transport hydrogen presents as the best solution, providing a levelized cost of hydrogen of 5.35 €/kgH2 for the baseline case, with the potential of being as low as 2.17 €/kgH2 if the EU support to hydrogen deployment achieves its targets. The energy requirement for this pathway is 0.46 MWh/MWhH2 (of lower heating value), being one of the less energy intensive methods. Another key insight of this work is that the commercialization of produced oxygen improves greatly the viability of the project, increasing the net present value by more than 150 M€ without major added complexities in the infrastructure. Also, a sensitivity analysis is performed to different variables (electrolyzer cost, capacity factor, electrolyzer system efficiency, plant distance to shore and the levelized cost of electricity) showing that the levelized cost of hydrogen is very dependent on the electricity and electrolyzer costs. Exibir menos

Several solutions and city planning policies have emerged to promote climate change and sustainable cities. The Sharing Cities program has the ambition of contributing to climate change mitigation by improving urban mobility, energy efficiency in buildings and reducing carbon emissions by successfully engaging citizens and fostering local-level innovation. A Digital Social Market (DSM), named Sharing Lisboa, was developed in Lisbon, Portugal, supported by an application (APP), enabling the… Exibir mais

Several solutions and city planning policies have emerged to promote climate change and sustainable cities. The Sharing Cities program has the ambition of contributing to climate change mitigation by improving urban mobility, energy efficiency in buildings and reducing carbon emissions by successfully engaging citizens and fostering local-level innovation. A Digital Social Market (DSM), named Sharing Lisboa, was developed in Lisbon, Portugal, supported by an application (APP), enabling the exchange of goods and services bringing citizens together to support a common cause: three schools competing during one academic year (2018/2019) to win a final prize with the engagement of school community and surrounding community. Sharing Lisboa aimed to promote behaviour change and the adoption of energy-saving behaviours such as cycling and walking with the support of local businesses. Participants earned points that reverted to the cause (school) they supported. A total of 1260 users was registered in the APP, collecting more than 850,000 points through approximately 17,000 transactions. This paper explores how the DSM has the potential to become a new city service promoting its sustainable development. Furthermore, it is crucial for this concept to reach economic viability through a business model that is both profitable and useful for the city, businesses and citizens, since investment will be required for infrastructure and management of such a market. Exibir menos

This work applies a multi-disciplinary methodology to develop an energy demand modelling framework for Tier 0 refugee camps, and assesses the implementation of alternative power supply systems. It does so by not only focusing on its techno-economic feasibility, but equally through investigating the challenges on adoption in the specific context of refugee camps, by undertaking interviews with relevant stakeholders in the humanitarian sector. The modelling application has been performed for the… Exibir mais

This work applies a multi-disciplinary methodology to develop an energy demand modelling framework for Tier 0 refugee camps, and assesses the implementation of alternative power supply systems. It does so by not only focusing on its techno-economic feasibility, but equally through investigating the challenges on adoption in the specific context of refugee camps, by undertaking interviews with relevant stakeholders in the humanitarian sector. The modelling application has been performed for the Mantapala refugee camp, in Zambia, enabling the comparison of different combinations of power supply systems against current diesel-based solutions, using HOMER software.
Results show that the implementation of hybrid renewable energy systems is viable, both technically and economically, with energy costs being reduced up to 50%, with paybacks lower than five years. However, from the interviews performed, some non-technical constraints that may hinder the adoption of these systems in refugee camps were identified, such as uncertainty, lack of funding and difficulties on risk-sharing collaborations. As such, a discussion focused on possible strategies that may help overcome these barriers is presented. Exibir menos

In a context where alternative services and products continue to arise mainly in urban centers to mitigate transport externalities, a very influential variable continues to be if people are willing to accept and use these new concepts. Consequently, the objective of this work was to analyze the potential consumer adoption of shared autonomous vehicles. The case study held in the Lisbon Metropolitan Area (LMA) in Portugal, considered a shared and autonomous vehicle, with an assumed cost of 7… Exibir mais

In a context where alternative services and products continue to arise mainly in urban centers to mitigate transport externalities, a very influential variable continues to be if people are willing to accept and use these new concepts. Consequently, the objective of this work was to analyze the potential consumer adoption of shared autonomous vehicles. The case study held in the Lisbon Metropolitan Area (LMA) in Portugal, considered a shared and autonomous vehicle, with an assumed cost of 7 cents/km in a 33-min trip. An average acceptance of 44% was obtained and affected by some of the considered variables. One of those variables was age, with younger people being more prone to adopt. In fact, people aged below 35 present more than 50% choice in shared, electric and autonomous vehicles, while for older groups, the percentages of choice are more distributed. People that usually drive are less prone to adopt shared and autonomous vehicles. Travel period also presents differences in alternative choice, since people that travel out of the rush-hour period are more reluctant to change. However, in order for this adoption to be successful, it is crucial to understand what makes people choose them and adopt and, for this, assessing lifestyles and behaviors plays an essential role. Exibir menos

This study analyzes climate change mitigation policies focused on light-duty electric vehicles (LDEVs) in the transportation sector in Rio de Janeiro state, Brazil, in the 2016–2050 period. We use the Open Source Energy Modeling System (OSeMOSYS) to analyze scenarios that consider greater uptake of LDEVs in different time frames, implementation of a CO2 emission restriction policy, exclusion of fossil fuels from the power mix, and a combination of these policies. We find that carbon pricing… Exibir mais

This study analyzes climate change mitigation policies focused on light-duty electric vehicles (LDEVs) in the transportation sector in Rio de Janeiro state, Brazil, in the 2016–2050 period. We use the Open Source Energy Modeling System (OSeMOSYS) to analyze scenarios that consider greater uptake of LDEVs in different time frames, implementation of a CO2 emission restriction policy, exclusion of fossil fuels from the power mix, and a combination of these policies. We find that carbon pricing, along with higher rates of LDEVs adoption, causes the highest emission reductions (up to 47%), albeit at higher costs. LDEVs become the preferred vehicle technology as soon as they reach cost parity with internal combustion engine vehicles in different scenarios. Greater LDEVs uptake, however, leads to increased electricity consumption (up to 3%), which is provided by fossil fuels when there is no emission restriction policy. If restrictions are placed on the expansion of fossil fuel power plants, fewer LDEVs are adopted (up to less than 26%) because there is not enough electricity to supply the demand. Given the state’s power mix in 2016 (58% provided by fossil fuels), investment in zero-carbon energy is necessary for mitigation policies in the transportation sector to be effective. Exibir menos

Past studies have shown that public support for battery electric (BEV) vans is justified by their emission external cost savings compared to their diesel equivalent. This study builds on this previous work and focuses on temperature effects on costs and energy use of large BEV and diesel vans. The authors find that temperature effect has relatively small private costs, when compared to the overall operational costs. However, it could reduce large BEV vans’ average range by up to 20% in cold… Exibir mais

Past studies have shown that public support for battery electric (BEV) vans is justified by their emission external cost savings compared to their diesel equivalent. This study builds on this previous work and focuses on temperature effects on costs and energy use of large BEV and diesel vans. The authors find that temperature effect has relatively small private costs, when compared to the overall operational costs. However, it could reduce large BEV vans’ average range by up to 20% in cold cities. Pre-heating the vans could mitigate these negative effects by 5-10%, 90-95% and 100% for 23.4, 46.8 and 70.2 kWh large BEV vans, respectively. Hence, policy makers should adopt different strategies according to city temperature profiles, prioritizing subsidies to charging stations in cold cities. Exibir menos

Ghana is one of the few countries within the sub-Saharan region which has been successful in reducing energy poverty. However, ensuring energy security, affordability, and environmental sustainability remains a significant challenge for the future development of the sub-region. Here, we examine how the electricity supply can evolve into the future to meet potential emission obligations for the period of 2020–2040. A generation expansion planning model which is able to incorporate the reality of… Exibir mais

Ghana is one of the few countries within the sub-Saharan region which has been successful in reducing energy poverty. However, ensuring energy security, affordability, and environmental sustainability remains a significant challenge for the future development of the sub-region. Here, we examine how the electricity supply can evolve into the future to meet potential emission obligations for the period of 2020–2040. A generation expansion planning model which is able to incorporate the reality of fuel shortages and fuel switching typical of a developing country's power system is used. In doing so, we generate a range of emission reduction costs that provide important benchmarks for the relatively under-studied sub-Saharan region and identify drivers of these costs specific to developing countries. Results indicate that the total discounted cost in expanding generation to meet the demand for all scenarios range from 13–17 billion US$, while the expected emission ranges from 99–189 mtCO2. Subsequently, the cost of meeting different emission targets up to 2040 was quantified for each scenario ranging from 11–39 US$/tonne, which could be used as a benchmark for comparison in developed countries. We find that discount rates, representing Ghana's access to capital, are a particularly important variable for developing countries. We find that lower discount rates can lead to more investment in capital intensive renewable energy in the long run but can also lock in an additional conventional generation investment in the short term. Sensitivity analysis of demand growth reduction shows that with a 1% growth rate, the requirement of generation capacity could be reduced by 84%, providing initial evidence for the benefits of investing in demand-side measures. The study provides data and policy recommendations needed to inform decision-makers in developing countries as well as a comparison point for identifying decarbonization costs internationally. Exibir menos

Demand-side management initiatives such as voluntary demand response provide significant energy savings in the residential sector, which is a major peak demand contributor. The potential of such savings remains unexplored in Ghanaian households due to insufficient electricity consumption data, lack of end-user behavior information and knowledge about the cost-effectiveness of such programs. This research combines 80 household survey information and energy use monitoring data of household… Exibir mais

Demand-side management initiatives such as voluntary demand response provide significant energy savings in the residential sector, which is a major peak demand contributor. The potential of such savings remains unexplored in Ghanaian households due to insufficient electricity consumption data, lack of end-user behavior information and knowledge about the cost-effectiveness of such programs. This research combines 80 household survey information and energy use monitoring data of household appliances, to assess the residential demand response potential of Ghana. A bottom-up approach based on modified end-use model is used to develop aggregate hourly load curve. The estimated electricity consumption is categorized based on their degree of control to determine peak demand reduction potential for the period 2018-2050. The average daily peak load reduction ranged between 65-406 MW representing 2-14% for the considered scenarios by 2050. The results show appreciable economic viability for investment in demand response with net present value varying between 28-645 million US$. We find that price, energy security and environment signals influence end-users’ electricity use behavior. Authors observe that for energy and cost savings to be realized, utility providers and consumers need effective cooperation on information delivery and feedbacks, and consumers should be incentivized to balance the benefits. Exibir menos

The research of renewable alternatives to decarbonize the transport sector and to reduce the consumption of fossil fuels pushes towards the development of more sustainable solutions for fuel production. Among the diesel substitutes, hydrotreated vegetable oil (HVO) is considered one of the most promising options, since it can be blended with fossil diesel without limitations. In this context, this paper assesses the technical and economic feasibility of producing HVO using waste vegetable oil… Exibir mais

The research of renewable alternatives to decarbonize the transport sector and to reduce the consumption of fossil fuels pushes towards the development of more sustainable solutions for fuel production. Among the diesel substitutes, hydrotreated vegetable oil (HVO) is considered one of the most promising options, since it can be blended with fossil diesel without limitations. In this context, this paper assesses the technical and economic feasibility of producing HVO using waste vegetable oil (WVO) as feedstock, with the help of a simulation model that maximizes the integration of renewable energy sources. The process to synthesize HVO requires a large amount of hydrogen that, in this study, is supplied through an upstream high-temperature electrolysis process occurring in solid oxide electrolysis cells (SOECs), which are fed by low-carbon electricity. The use of waste oils as feedstock eliminates the competition with food crops (e.g. soybean or rapeseed) and promotes the recycling of substances that need to be disposed. The results of the study prove the technical feasibility of a plant with an annual capacity of 100 kt of HVO, having an energy efficiency of 80%. Also, the breakeven point of such investment would be reached before the fourth year of operation, considering a WVO price of 400 €/t, which is assumed as target price. However, the uncertainty on the market prices of WVO, HVO and electricity, as well as on other fixed and variable production costs, can significantly affect the projected results. Exibir menos

This work focuses on developing a novel method to relate certification driving cycle dynamics and on-road test vehicle dynamics, to evaluate RDE tests fuel use and exhaust emissions in a comparable way to certification driving cycles, indicating how close, or far, real-world driving is from the laboratorial certification test. For this, a new method was developed called road vehicle evaluation method (ROVET), which relies on the cycle vehicle dynamic and on-road trip dynamics for assessing if… Exibir mais

This work focuses on developing a novel method to relate certification driving cycle dynamics and on-road test vehicle dynamics, to evaluate RDE tests fuel use and exhaust emissions in a comparable way to certification driving cycles, indicating how close, or far, real-world driving is from the laboratorial certification test. For this, a new method was developed called road vehicle evaluation method (ROVET), which relies on the cycle vehicle dynamic and on-road trip dynamics for assessing if both tests are comparable. Results from 5 measured vehicles with a portable emissions measurement system (PEMS) through reproducibility tests and 2 case studies, show that the ROVET provides results closer to the certification calculated reference than the most commonly used method in Europe (1% avg. difference for ROVET while 8% avg. difference for MAW_EC, regarding CO2 emission, for example). The use of vehicle dynamics on construction and references of a method could be used to incentivize the regulators to review the references used by the current used methods, which suffers several criticisms since their release. As the regulated methods are in constant update, this study could be useful for helping to improve or to be used as additional method for future vehicle certification procedures. Exibir menos

As the socio-economic need of mankind and population continue to grow, electricity consumption estimates become necessary for energy system planning. In Ghana, residential electricity is currently the second largest and growing rapidly. Unfortunately, adequate and reliable data on electricity consumption of household appliances is insufficient to enhance policy design and implementation. Therefore, the aim of this paper is to comprehensively disaggregate and characterize the residential… Exibir mais

As the socio-economic need of mankind and population continue to grow, electricity consumption estimates become necessary for energy system planning. In Ghana, residential electricity is currently the second largest and growing rapidly. Unfortunately, adequate and reliable data on electricity consumption of household appliances is insufficient to enhance policy design and implementation. Therefore, the aim of this paper is to comprehensively disaggregate and characterize the residential electricity demand in Ghana. Nine scenarios were designed and tested between 2015 and 2050, considering 21 household appliances and 4 lighting technologies under 8 classes of electricity end-uses. A bottom-up approach based on stock accounting model and a technological-based top-down approach were adopted to estimate electricity consumption using demand factors such as population, gross domestic product and appliance ownership. Electricity consumption in 2015 was estimated as 3146 GW h for all scenarios while it varied between 6596 GW h and 19693 GW h by 2050. The results show that seven appliances and one lighting technology consisting of refrigerator, air conditioner, television, freezer, fan, electric iron, washing machine and CFL constituted about 93% of residential electricity consumption in 2015 and are projected to hold a dominant 90% share in 2050. Exibir menos

This work goal was to assess how driving aggressiveness is influenced by the type of road and by the road grade, and consequently their impacts on fuel consumption. For that purpose, 47 drivers were monitored in the Lisbon Metropolitan Area during 6 months, allowing building an extensive 1 Hz real world driving database (∼33,000 trips, totalizing 28.9 million seconds). This database provided distinctive and representative data, allowing assessing the impacts on fuel consumption rates. Results… Exibir mais

This work goal was to assess how driving aggressiveness is influenced by the type of road and by the road grade, and consequently their impacts on fuel consumption. For that purpose, 47 drivers were monitored in the Lisbon Metropolitan Area during 6 months, allowing building an extensive 1 Hz real world driving database (∼33,000 trips, totalizing 28.9 million seconds). This database provided distinctive and representative data, allowing assessing the impacts on fuel consumption rates. Results showed that both road context and aggressive driving behavior impact fuel consumption rates significantly. However, for non-aggressive driving behavior fuel consumption rates increased more with road grade increments (up to 3 times) than for aggressive driving behavior (up to 2.3 times). Furthermore, this study results demonstrated that aggressiveness influences fuel consumption differently across road grades. Aggressiveness impacts are higher for lower road grades, with increased fuel consumption rates by up to 255%. The key findings associated to this research work are that aggressiveness on roads with lower grades tends to correlate with higher percent increase on fuel consumption for all speed ranges. Moreover, aggressiveness seems to correlate with higher fuel consumption on urban streets. Consequently, a reduction in driving under these conditions can offer significant savings in fuel consumption. Exibir menos

Enhanced biogas production from anaerobic co-digestion of pig slurry and horse manure with mechanical pre-treatment. In this study, co-digestion of horse manure and pig slurry was investigated in a continuously stirred tank reactor, with a mechanical pre-treatment. Experiments were conducted at 37°C, with hydraulic retention times of 23 days and increasing shares of horse manure, corresponding to different horse manure to pig slurry ratios (HM:PS) equal to 0:100, 10:90, 13:87 and 20:80, in… Exibir mais

Enhanced biogas production from anaerobic co-digestion of pig slurry and horse manure with mechanical pre-treatment. In this study, co-digestion of horse manure and pig slurry was investigated in a continuously stirred tank reactor, with a mechanical pre-treatment. Experiments were conducted at 37°C, with hydraulic retention times of 23 days and increasing shares of horse manure, corresponding to different horse manure to pig slurry ratios (HM:PS) equal to 0:100, 10:90, 13:87 and 20:80, in terms of percentage of inlet volatile solids (%VS inlet). The results show that the best synergetic effect between the microbial consortia of pig slurry and the high Carbon to Nitrogen ratio (C/N) of horse manure is obtained for the mixture of 20:80%VS inlet, yielding the highest specific methane production (SMP = 142.6 L kgTCOD−1) and the highest soluble chemical oxygen demand (SCOD) reduction (68.5%), due to the high volatile dissolved solids content and soluble chemical oxygen demand to total chemical oxygen demand ratio (SCOD/TCOD). Thus, co-digestion of horse manure and pig slurry is shown to be a promising approach for biogas production and as a waste treatment solution. Furthermore, the analysis provides a methodology for the pre-treatment of these substrates and to investigate into the best combination for improved biogas production. Exibir menos

Global household electricity consumption of appliances is anticipated to double by 2030, with most of the growth expected to occur in developing countries. The rising electricity consumption is triggered by population growth, economic development, change in lifestyle and increasing domestic appliance ownership. In Ghana, population is projected to be 40 million by 2030, with an average annual growth rate of 2.5%. Presently, urban centres account for 55% of the population and 70% of the… Exibir mais

Global household electricity consumption of appliances is anticipated to double by 2030, with most of the growth expected to occur in developing countries. The rising electricity consumption is triggered by population growth, economic development, change in lifestyle and increasing domestic appliance ownership. In Ghana, population is projected to be 40 million by 2030, with an average annual growth rate of 2.5%. Presently, urban centres account for 55% of the population and 70% of the residential electricity consumption. With the government’s efforts of decreasing rural to urban migration through its district industrialization agenda, the evolution of electricity demand becomes uncertain due to the
uncertainty of how “urbanisation” or “ruralisation” influences residential electricity consumption. Consequently, the main objective of this study is to estimate the future demand for electricity in urban and rural contexts (2015-2050) under different migration scenarios (High, Medium, Low). In this study, 21 household appliances and 4 lighting technologies are
categorised under 8 different end-uses and modelled. A hybrid approach is used, combining a bottom-up approach to estimate electricity consumption with top-down data from population, income and appliance ownership. The results of the 3 scenarios show that by 2050 the rural consumption maybe 19%, 67% and 134% of the urban consumption for the High, Medium and Low scenarios, respectively. Exibir menos

This work presents an analysis of electric mobility feasibility and adequacy based on private users' naturalistic driving data. Several scenarios were tested to evaluate different charging event opportunities and their impacts on electric mobility feasibility. In more detail, scenario 1 considered that vehicles would recharge whenever they are stopped for 2, 4 or 6 h, either on weekdays or weekend days; scenario 2 tested the hypothesis of recharging only during the night period; and scenario 3… Exibir mais

This work presents an analysis of electric mobility feasibility and adequacy based on private users' naturalistic driving data. Several scenarios were tested to evaluate different charging event opportunities and their impacts on electric mobility feasibility. In more detail, scenario 1 considered that vehicles would recharge whenever they are stopped for 2, 4 or 6 h, either on weekdays or weekend days; scenario 2 tested the hypothesis of recharging only during the night period; and scenario 3 assumed that vehicles would recharge during the day on weekdays. Furthermore, the potential energy impacts of electric mobility at a city level, by applying a driver and street level approach, were also estimated.
Results revealed that electric mobility is highly feasible for weekday urban trips, while weekend trips due to their higher average distance are less suitable to be performed by EVs. Scenario 1, due to its higher recharging opportunities was found to be the best-case scenario. In this case, the percentage of eligible trips was found to be equal to or higher than 94% and 88% on weekdays and weekend days, respectively. Results showed also the lower electric mobility feasibility if considering only daytime charging, on weekdays (scenario 3). However, if considering night charging (scenario 2), the electric mobility eligibility was found to improve significantly. When considering a street level analysis, the potential reduction in energy consumption ranges in average from −60 to −70%, enabling the visualization of higher EV potential, with increasing potential for reducing energy consumption for increasing road grades. Exibir menos

Thus, this work focuses on analyzing the effect of different data measurement and analysis methods (i.e. cold-operation, road grade, trip selection and driving style) on CO2 and nitrogen oxides (NOx) emissions based on 13 RDE tests performed in the Lisbon Metropolitan Area, Portugal.
Results show the effects of each parameter such as average difference between drivers (7% in CO2 and 55% in NOx emissions) and between aggressive and normal driving. For road grade, big oscillations happen… Exibir mais

Thus, this work focuses on analyzing the effect of different data measurement and analysis methods (i.e. cold-operation, road grade, trip selection and driving style) on CO2 and nitrogen oxides (NOx) emissions based on 13 RDE tests performed in the Lisbon Metropolitan Area, Portugal.
Results show the effects of each parameter such as average difference between drivers (7% in CO2 and 55% in NOx emissions) and between aggressive and normal driving. For road grade, big oscillations happen during the slope profile, which impacts emissions during all trips. Considering cold-operation, CO2 and NOx emissions are, on average, ~25% and 55% higher, respectively, than in hot-operation. Exibir menos

This work assesses the impacts of aggressive driving behavior on pollutants emissions and energy consumption at a city level. Furthermore, it performs an economic analysis considering the potential avoided emissions and fuel savings and discusses potential policy measures to address this topic. The results showed that aggressive driving significantly impacts energy consumption and emissions, with energy consumption increasing by more than ∼200% and emissions by 330% for aggressive driving… Exibir mais

This work assesses the impacts of aggressive driving behavior on pollutants emissions and energy consumption at a city level. Furthermore, it performs an economic analysis considering the potential avoided emissions and fuel savings and discusses potential policy measures to address this topic. The results showed that aggressive driving significantly impacts energy consumption and emissions, with energy consumption increasing by more than ∼200% and emissions by 330% for aggressive driving compared to non-aggressive driving (in MJ/km and in g/km, respectively). This increment was found to be even higher for diesel vehicles than for gasoline vehicles. On the contrary, gasoline vehicles showed higher percentages of increase for most emissions (CO, NOx and NO). Results also revealed that aggressive driving impacts are higher for local streets when examining the city level. Moreover, the economic analysis showed that significant cost reductions may be achieved by avoiding aggressive driving, reaching up to 52.5 k€ on a daily basis. Exibir menos

Este artigo compara o consumo de energia, as emissões de CO2 e as políticas públicas de duas megacidades, São Paulo (SP) e Xangai (XG), a fim de identificar suas políticas de mitigação de emissões de GEE. Ambas as cidades experimentaram um rápido crescimento dos setores automotivos, resultando em desafios consideráveis ​​de poluição e emissão de CO2. SP implementou com sucesso o etanol e incentivou o crescimento da frota de veículos ligeiros. XG tem geração de energia baseada em carvão e… Exibir mais

Este artigo compara o consumo de energia, as emissões de CO2 e as políticas públicas de duas megacidades, São Paulo (SP) e Xangai (XG), a fim de identificar suas políticas de mitigação de emissões de GEE. Ambas as cidades experimentaram um rápido crescimento dos setores automotivos, resultando em desafios consideráveis ​​de poluição e emissão de CO2. SP implementou com sucesso o etanol e incentivou o crescimento da frota de veículos ligeiros. XG tem geração de energia baseada em carvão e restringe a compra de carros. Investiu na expansão do transporte público e encoraja a eletrificação da mobilidade. Análise tabular de dados secundários foi adotada neste estudo, revelando também que SP expandiu consideravelmente o transporte individual. Apesar dos investimentos em etanol, a cidade não conteve o aumento das emissões de CO2. XG investiu em transporte público e inibiu o transporte individual, mas também não conseguiu conter as emissões de CO2. As políticas de mitigação não evitaram o aumento das emissões de CO2 em ambas as cidades. Para reduzir as emissões de CO2 nos transportes, SP e XG devem se concentrar em políticas públicas para incentivar o transporte público de baixo carbono e limitar a queima de combustíveis fósseis. Exibir menos

The potential of logistic sharing solutions and respective transport capabilities to reduce emissions and mitigate the transport sector's impacts on climate change comes along with benefits to companies with the reduction of overall operating expenses, by reducing transport costs per kilogram and cutting maintenance and personnel costs, as fewer assets are needed. To the public sector, the benefits are still mostly felt in terms of environment as a consequence of the more effective use of… Exibir mais

The potential of logistic sharing solutions and respective transport capabilities to reduce emissions and mitigate the transport sector's impacts on climate change comes along with benefits to companies with the reduction of overall operating expenses, by reducing transport costs per kilogram and cutting maintenance and personnel costs, as fewer assets are needed. To the public sector, the benefits are still mostly felt in terms of environment as a consequence of the more effective use of resources. In fact, in spite the recent emergence of logistics sharing solutions, the topic has not been sufficiently explored under a perspective that: a) highlights the role that municipalities can play to benefit from the sharing economy model and; b) analyzes case studies in which municipalities provide owned assets to be shared by logistics players.

The objective of this paper is to contribute to reduce that hiatus on research by assessing the impact of logistic sharing solutions under a public good perspective. Therefore, the paper analyses the potential impacts of promoting the shared usage of logistic parking infrastructure owned by public authorities. As a demonstration of that potential, the possible benefits of sharing parking spaces dedicated to urban logistics operations by other users were studied, in particular the parents taking children to kindergartens located in the area. The paper is supported by a case study carried out in a Portuguese city and the effects are quantified in metrics of transport performance, energy and environmental criteria. The scenario is compared to a baseline situation (BAU) and results show significant reductions in delay times, travel times, queue lengths and stopped times and increases in average speeds. Also, fuel consumption and emissions present considerable reductions in the tested scenario. Exibir menos

This paper presents an innovative methodology that uses an extensive and complementary real-world dataset to make a scenario-based analysis allowing assessing energy consumption impacts of shifting traffic from peak to off-peak hours. In the specific case of the city of Lisbon, a sample of 40 drivers was monitored for a period of six months. The obtained data allowed testing the impacts of increasing the percentage of traffic shifting from peak to off-peak hours in energy consumption. Both… Exibir mais

This paper presents an innovative methodology that uses an extensive and complementary real-world dataset to make a scenario-based analysis allowing assessing energy consumption impacts of shifting traffic from peak to off-peak hours. In the specific case of the city of Lisbon, a sample of 40 drivers was monitored for a period of six months. The obtained data allowed testing the impacts of increasing the percentage of traffic shifting from peak to off-peak hours in energy consumption. Both average speed and energy consumption variations were quantified for each of the tested percentages, allowing concluding that for traffic shifts of up to 30% a positive impact in consumption can be observed. In terms of potential gains associated to shifting traffic from peak hours, reductions in energy consumption from 0.1% to 0.4% can be obtained for traffic volumes shifts from 5 to 30%. Overall, the maximum reduction in energy consumption is achieved for a 20% traffic shift. Average speed variation follows the same trend as energy consumption, but in the opposite direction, i.e. instead of decreasing, average speed increases. For the best case scenario, considering only the sections of roads with traffic sensors, a 1.4% reduction in trip time may be achieved, as well as savings of up to 6 l of fuel and 14.5 kg of avoided CO2 emissions per day. Exibir menos

This study aims at estimating energy consumption, energy savings and peak demand reduction by introducing different standards and labelling regimes for some household appliances under different gross domestic product (GDP) scenarios for the period 2020–2050. The analysis concentrates on 5 intensive energy consuming appliances: refrigerator, freezer, air conditioner, washing machine and television; and 4 lighting technologies. A bottom-up and a top-down approach were adopted to estimate… Exibir mais

This study aims at estimating energy consumption, energy savings and peak demand reduction by introducing different standards and labelling regimes for some household appliances under different gross domestic product (GDP) scenarios for the period 2020–2050. The analysis concentrates on 5 intensive energy consuming appliances: refrigerator, freezer, air conditioner, washing machine and television; and 4 lighting technologies. A bottom-up and a top-down approach were adopted to estimate electricity consumption with the dynamic characteristics of data such as appliance ownership, population and GDP. The summary results indicate that with the implementation of the various energy efficiency scenarios, the energy consumption of the 5 appliances and 4 lighting technologies can be reduced by 24–51% in 2050 while the estimated potential cumulative energy savings range 31–104 TWh for the 30-year period. The peak demand reduction in 2050 ranges 721–2952 MW for all scenarios considered and represents 40–165% of Ghana's peak demand in 2013. Refrigerators were found to account for the highest share of the cumulative energy savings, 37–57%, while televisions contribute the highest, 28–42%, to peak demand reduction by 2050. The methods deployed in this study can easily be adapted for related studies in other countries with even little household load data, providing an important instrument for helping decision makers set adequate energy efficiency policies. Exibir menos

This paper addresses the progress that Portugal is making toward a more sustainable transport sector. A near- and medium- term scenario analysis is performed, based on the energy consumption in the past and on a detailed evaluation of the trends for renewable energy in the transport sector. The near-term scenarios aim at portraying the conditions that allow the country to fulfill the target of 10% renewable share in transportation established by the European Union. The medium-term scenarios… Exibir mais

This paper addresses the progress that Portugal is making toward a more sustainable transport sector. A near- and medium- term scenario analysis is performed, based on the energy consumption in the past and on a detailed evaluation of the trends for renewable energy in the transport sector. The near-term scenarios aim at portraying the conditions that allow the country to fulfill the target of 10% renewable share in transportation established by the European Union. The medium-term scenarios highlight the implications, in terms of emission reduction and of energy independence, deriving from the use of electric vehicles and natural gas, synthetic and fossil, as alternatives to liquid fuels. The results show that electric vehicles would substantially reduce the total energy consumption and the greenhouse gas emissions, while the promotion of routes for synthetic natural gas would contribute to taking advantage of local resources. The paper also provides some insights about the design of future policies to build a more sustainable transport sector. Exibir menos

The popularity of car sharing as part of the urban mobility repertoire has barely increased from a niche contribution in recent decades. Although holding potential to address local issues such as congestion and air quality, but even more crucially to meet the urgent need to mitigate carbon dioxide emissions from traffic, car sharing often meets barriers stemming from local contexts, regulatory environments, and/or lack of political support or consumer awareness. In this article, we discuss the… Exibir mais

The popularity of car sharing as part of the urban mobility repertoire has barely increased from a niche contribution in recent decades. Although holding potential to address local issues such as congestion and air quality, but even more crucially to meet the urgent need to mitigate carbon dioxide emissions from traffic, car sharing often meets barriers stemming from local contexts, regulatory environments, and/or lack of political support or consumer awareness. In this article, we discuss the interdependencies of these barriers and provide some key elements to consider in the future when planning practical implementation, research initiatives, and policy support for car sharing in order to overcome the complex and interrelated barriers. Exibir menos

This research work analyzes and quantifies the impacts of cold start in urban context using naturalistic driving data. Furthermore, an assessment of the influence of ambient temperature on the percentage of time spent on cold start was also performed.
Regarding the impacts of ambient temperature on cold start duration, a higher percentage of time spent on cold start was found for lower ambient temperatures (80% of the time for 0 °C and ~50% for 29 °C). Results showed that, during cold start,… Exibir mais

This research work analyzes and quantifies the impacts of cold start in urban context using naturalistic driving data. Furthermore, an assessment of the influence of ambient temperature on the percentage of time spent on cold start was also performed.
Regarding the impacts of ambient temperature on cold start duration, a higher percentage of time spent on cold start was found for lower ambient temperatures (80% of the time for 0 °C and ~50% for 29 °C). Results showed that, during cold start, energy consumption is >110% higher than during hot conditions while emissions are up to 910% higher. Moreover, a higher increase on both energy consumption and emissions was found for gasoline vehicles than for diesel vehicles. When assessing the impacts on a city perspective, results revealed that the impacts of cold start increase for more local streets.
The main finding of this study is to provide evidence that a higher increase on emissions occurs on more local streets, where most of the population lives. This kind of knowledge is of particular relevance to urban planners in order to perform an informed definition of public policies and regulations to be implemented in the future, to achieve a cleaner and healthier urban environment. Exibir menos

A life-cycle analysis was applied to the road passenger transport, for the European Union with 27 countries (EU27) in 2010, following a basket-of-products methodology and considering three main stages: production, use, and end-of-life of vehicles. Simapro 8 software was used, along with Ecoinvent 3 database and the impact assessment method International Reference Life Cycle Data System (ILCD) 2011 Midpoint+. Changes in vehicle production processes, vehicle constitution, and energy sources for… Exibir mais

A life-cycle analysis was applied to the road passenger transport, for the European Union with 27 countries (EU27) in 2010, following a basket-of-products methodology and considering three main stages: production, use, and end-of-life of vehicles. Simapro 8 software was used, along with Ecoinvent 3 database and the impact assessment method International Reference Life Cycle Data System (ILCD) 2011 Midpoint+. Changes in vehicle production processes, vehicle constitution, and energy sources for vehicle propulsion were analyzed. The policies resulting in a decrease in all impact categories are the use of smaller or lightweight vehicles by positively influencing use, production, and end-of-life of vehicles. The use of more recent vehicles technology or diesel vehicles show substantial reductions in, respectively, five and eight impact categories (out of 15), justifying their adoption in the European fleet. Generally, the most notorious policies compared to the actual transport paradigm, like compressed natural gas (CNG), biofuels, or electric vehicles use, show the greatest reduction in climate change (up to 46%) but also a very significant rise of impacts in the categories that in the conventional basket-of-products already resulted in the worst indicators after normalization. Exibir menos

In this study, co-digestion of horse manure and pig slurry was investigated in a continuously stirred tank reactor, with a mechanical pre-treatment. Experiments were conducted at 37°C, with hydraulic retention times of 23 days and increasing shares of horse manure, corresponding to different horse manure to pig slurry ratios (HM:PS) equal to 0:100, 10:90, 13:87 and 20:80, in terms of percentage of inlet volatile solids (%VS inlet). The results show that the best synergetic effect between the… Exibir mais

In this study, co-digestion of horse manure and pig slurry was investigated in a continuously stirred tank reactor, with a mechanical pre-treatment. Experiments were conducted at 37°C, with hydraulic retention times of 23 days and increasing shares of horse manure, corresponding to different horse manure to pig slurry ratios (HM:PS) equal to 0:100, 10:90, 13:87 and 20:80, in terms of percentage of inlet volatile solids (%VS inlet). The results show that the best synergetic effect between the microbial consortia of pig slurry and the high Carbon to Nitrogen ratio (C/N) of horse manure is obtained for the mixture of 20:80%VS inlet, yielding the highest specific methane production (SMP = 142.6 L kgTCOD−1) and the highest soluble chemical oxygen demand (SCOD) reduction (68.5%), due to the high volatile dissolved solids content and soluble chemical oxygen demand to total chemical oxygen demand ratio (SCOD/TCOD). Thus, co-digestion of horse manure and pig slurry is shown to be a promising approach for biogas production and as a waste treatment solution. Furthermore, the analysis provides a methodology for the pre-treatment of these substrates and to investigate into the best combination for improved biogas production. Exibir menos

This work presents a methodology to help local authorities with the development of an Energy Action Plan (EAP) towards more sustainable municipal energy systems and, simultaneously, ease the related decision process, by using MCDA. The developed methodology was applied to the municipality of Odemira, Portugal. After several interactions with stakeholders, a set of 16 actions was chosen. Once applied the ELECTRE III method, public lighting, the conversion of the swimming pool water heaters for… Exibir mais

This work presents a methodology to help local authorities with the development of an Energy Action Plan (EAP) towards more sustainable municipal energy systems and, simultaneously, ease the related decision process, by using MCDA. The developed methodology was applied to the municipality of Odemira, Portugal. After several interactions with stakeholders, a set of 16 actions was chosen. Once applied the ELECTRE III method, public lighting, the conversion of the swimming pool water heaters for biomass fueled, the matching of bus and train schedules and the installation of solar photovoltaic systems on the municipal exposition park were the best-ranked actions to be adopted. Also, up to 3 kton of carbon dioxide emissions can be avoided per year if the EAP is implemented, being observed higher benefits at the residential and services sectors. The decision of implementing these actions now stands with the municipality, which should start by implementing the most preferred actions first, and then proceed with the implementation of the subsequent actions, according to financial and human resources availability. Exibir menos

The aim of this paper is to assess drivers’ self-perceptions on their driving performance after an experimental on-road monitoring trial in which they received feedback on performance. Drivers’ self-perceptions on their driving performance were compared with their driving data.

Results indicate that majority of drivers considered the information presented in the feedback reports as being important, particularly in what concerned fuel consumption (fuel spent while driving) and… Exibir mais

The aim of this paper is to assess drivers’ self-perceptions on their driving performance after an experimental on-road monitoring trial in which they received feedback on performance. Drivers’ self-perceptions on their driving performance were compared with their driving data.

Results indicate that majority of drivers considered the information presented in the feedback reports as being important, particularly in what concerned fuel consumption (fuel spent while driving) and aggressiveness (extreme braking and acceleration) indicators. Nonetheless, the same level of importance is not given to indicators that largely influence or not paying any attention to them when driving. Such results might be indicative that participants give preference to fuel efficiency when driving, having the intention to improve fuel consumption, but might find it difficult to understand and apply eco-driving techniques.

The majority of drivers perceived their behaviour suffered ‘little’ to ‘some changes’, particularly in fuel consumption and aggressiveness. The comparison with driving data revealed that drivers increased the incidence of unwanted behaviours when they considered that their performance suffered ‘some changes’. On the contrary, decreases in some indicators, such as aggressiveness, speeding and excess rpm, were observed when ‘no changes’ were perceived by the drivers. These results are indicative that drivers are not correctly aware of changes in their performance. Exibir menos

The objective of this research work was to identify driving behavior patterns for several driving contexts (based on hierarchical street level and weather conditions) from real-world driving data and to assess their impacts on energy consumption. The case study for this work was the city of Lisbon, where driving data from 46 drivers were collected with on-board data loggers for at least 6 months.
The analysis performed in this work provides an insight on the impacts of driving context on… Exibir mais

The objective of this research work was to identify driving behavior patterns for several driving contexts (based on hierarchical street level and weather conditions) from real-world driving data and to assess their impacts on energy consumption. The case study for this work was the city of Lisbon, where driving data from 46 drivers were collected with on-board data loggers for at least 6 months.
The analysis performed in this work provides an insight on the impacts of driving context on driving behavior and consequently on energy consumption. Both infrastructure characteristics and weather conditions were found to cause a speed reduction and an energy consumption increase. Rain intensity was found to increase energy consumption up to 16%, while regarding infrastructure characteristics, for level 4 streets, energy consumption is 54% higher than for level 1 streets. Results provide evidence that drivers tend to drive more calmly (lower speeds and acceleration patterns) for higher rain intensities compared with dry weather. However, more local streets (level 2, 3 and 4 streets) are the ones that present more aggressive driving patterns (in terms of acceleration). Exibir menos

Abstract:
The main purposes of this research were, in a first stage, to assess the impacts of real-time feedback on the driving behavior of bus drivers, considering vehicle age and type and drivers experience and, in a second stage, to identify the main influential variables in fuel consumption. Data was collected with an on-board device used by a Portuguese urban bus transport operator. Significant increases in the performance of undesirable events were observed without real-time feedback… Exibir mais

Abstract:
The main purposes of this research were, in a first stage, to assess the impacts of real-time feedback on the driving behavior of bus drivers, considering vehicle age and type and drivers experience and, in a second stage, to identify the main influential variables in fuel consumption. Data was collected with an on-board device used by a Portuguese urban bus transport operator. Significant increases in the performance of undesirable events were observed without real-time feedback, followed by decreases with the restart of real-time feedback. Higher increases (between 6% and 170%) were observed when driving Mini vehicles in comparison with other bus types, particularly in extreme accelerations, excess rpm, extreme braking, and hard starts. Furthermore, a General Linear Model was applied to assess the most influential variables on fuel consumption. Vehicle type and age are the most influential variables on fuel consumption, with minibuses presenting higher increases when compared with standard buses. Increases up to 3% were observed leading to an extra 3769 liters of fuel consumed when feedback was not provided. Decreases in fuel consumption between 0.3% and 2% were observed with real-time feedback, avoiding the consumption of 4280 L of fuel. The results obtained in this paper provide bus companies with insightful information for the development of future operational strategies and training programs. Exibir menos

This paper develops a performance evaluation of re-routing for passenger and commercial vehicles with a case study in the city of Lisbon, Portugal. The paper examines how the provision of guidance information to drivers affects traffic performance, operational costs and environmental conditions at different spatial references, namely route level and urban network level. The simulation results indicate that the re-routing can not only reduce travel times, but also enhance the efficiency of roads… Exibir mais

This paper develops a performance evaluation of re-routing for passenger and commercial vehicles with a case study in the city of Lisbon, Portugal. The paper examines how the provision of guidance information to drivers affects traffic performance, operational costs and environmental conditions at different spatial references, namely route level and urban network level. The simulation results indicate that the re-routing can not only reduce travel times, but also enhance the efficiency of roads in the city network and as well the traffic performance at the route level of analysis. The improvement at local route levels (such as corridor/route) is more significant than at the city network level. For the urban network level, simulation results suggest that re-routing can bring variations in travel and delays that may reach 2% and 6%, respectively, when a 10% drivers’ compliance rate is considered. Individual drivers are more likely to comply to deviate than urban logistics drivers and bus drivers. Exibir menos

This work studies the effect of external environmental temperature in RDE tests, focusing on the analysis of the cold-start period in energy consumption and NOx emissions. Two vehicles (one diesel and one gasoline) were monitored, covering external temperatures from circa 1°C to 17°C (considered ranges of 5°C up to 15°C) in Lisbon, Portugal. A Portable Emissions Measurement System (PEMS) was used to collect 1 Hz data on vehicle dynamics, road topography, engine data and exhaust gas composition.… Exibir mais

This work studies the effect of external environmental temperature in RDE tests, focusing on the analysis of the cold-start period in energy consumption and NOx emissions. Two vehicles (one diesel and one gasoline) were monitored, covering external temperatures from circa 1°C to 17°C (considered ranges of 5°C up to 15°C) in Lisbon, Portugal. A Portable Emissions Measurement System (PEMS) was used to collect 1 Hz data on vehicle dynamics, road topography, engine data and exhaust gas composition. Data collected on both powertrain configurations is compared and analyzed using European Commission proposed method for RDE tests, as well as other methods to observe the impact of the cold-start phenomena in the normal day-to-day usage of vehicles. For the determination of cold-start periods, coolant temperature data was used as proxy to determine cold and normal operation. Results indicate that the initial ambient temperature have impacts in the duration of the cold-start period during a RDE test but not as relevant as expected, mostly at low temperatures compared to higher temperatures. NOx emissions can be around 30% higher in near 5°C temperatures for the diesel vehicle tested when compared with the other temperatures range. For the gasoline vehicle tested, the effect of the ambient outdoor temperature is not as significant as in diesel vehicles. Exibir menos

The paper assess the impacts of electric cargo bikes, from a public policy perspective and, simultaneously, taking into account variables that cover the urban logistics operators’ interests. Under a public policy perspective, the considered variables evaluate mobility, environmental impacts and indirectly, the quality of life. In terms of private interests, the studied variables cover costs levels (operation and driving) and efficiency. This evaluation aims at clarifying if electric cargo bikes… Exibir mais

The paper assess the impacts of electric cargo bikes, from a public policy perspective and, simultaneously, taking into account variables that cover the urban logistics operators’ interests. Under a public policy perspective, the considered variables evaluate mobility, environmental impacts and indirectly, the quality of life. In terms of private interests, the studied variables cover costs levels (operation and driving) and efficiency. This evaluation aims at clarifying if electric cargo bikes can indeed represent a sustainable mobility policy under specific boundaries, by leading to better environmental and social impacts and not hindering the operational efficiency of urban logistics activities. Exibir menos

The aim of this study was to analyse the impacts of real-time feedback on the driving
behaviour of bus drivers, and to assess the potential impact of the characteristics of these
subjects (age and time working at the company) on such behaviour. Data was collected
with an on-board device installed in buses of a Portuguese urban transport operator. Three
monitoring periods were considered: an initial phase, in which real-time feedback was
given to drivers (phase 1), followed by a… Exibir mais

The aim of this study was to analyse the impacts of real-time feedback on the driving
behaviour of bus drivers, and to assess the potential impact of the characteristics of these
subjects (age and time working at the company) on such behaviour. Data was collected
with an on-board device installed in buses of a Portuguese urban transport operator. Three
monitoring periods were considered: an initial phase, in which real-time feedback was
given to drivers (phase 1), followed by a period of no feedback (phase 2), and then a final
stage in which feedback was resumed (phase 3). A repeated measures analysis of variance
was performed to assess the impacts of feedback in several driving indicators across the
aforementioned phases. The results revealed that bus drivers accrue benefits from the
feedback received, with significant differences between the three monitoring periods for all
driving indicators analysed. After suspending the feedback, increases between 6% and 55%
of the incidence of undesired driving indicators were observed, mainly in extreme brakes,
extreme accelerations, excess RPM, and hard stops. Such insights can provide bus
operators with new tools to develop programs promoting efficient driving behaviours. Exibir menos

The scope of this study was to evaluate the RDE data analysis methods, including the Vehicle Specific Power methodology (used on MOVES model), applied to 1 Hz on-road data from 3 vehicle propulsion technologies (spark-ignition, compression-ignition and hybrid), collected in Lisbon, Portugal. This approach allowed analyzing and identifying the differences between the methods for each vehicle propulsion technology. Regarding total CO2 emissions and NOx emissions, the application of the methods… Exibir mais

The scope of this study was to evaluate the RDE data analysis methods, including the Vehicle Specific Power methodology (used on MOVES model), applied to 1 Hz on-road data from 3 vehicle propulsion technologies (spark-ignition, compression-ignition and hybrid), collected in Lisbon, Portugal. This approach allowed analyzing and identifying the differences between the methods for each vehicle propulsion technology. Regarding total CO2 emissions and NOx emissions, the application of the methods indicates that the MAW provides an overall difference of around 7% for CO2 and 10% for NOx comparing with the PB method. The PB is conceptually similar to VSP, although an overall 10% for CO2 and 19% for NOx difference was found. Differences on the methods results are due to the use of different approaches and, consequently, lead to different results, which are more explained on this paper. Exibir menos

• Impacts of delayed feedback on eco-driving behavior of passenger vehicle drivers.
• Increases over 5% in fuel consumption and CO2 emissions in both groups.
• Female drivers presented higher increases than male drivers.
• Results related with performance of accelerations, idling and short trips.
• Negative feedback led to short-term improvements and positive to performance decline.

Considering electric mobility as a viable alternative to conventional technologies, it is essential to characterize electric vehicles in terms of their real-world energy use. The objective of this work was to characterize in detail the real-world energy use of battery electric vehicles. An innovative method was developed through a calibration procedure using a group of three electric quadricycles, which were measured in real world on-road conditions for several trips by collecting 1 Hz data on… Exibir mais

Considering electric mobility as a viable alternative to conventional technologies, it is essential to characterize electric vehicles in terms of their real-world energy use. The objective of this work was to characterize in detail the real-world energy use of battery electric vehicles. An innovative method was developed through a calibration procedure using a group of three electric quadricycles, which were measured in real world on-road conditions for several trips by collecting 1 Hz data on vehicle dynamics (speed, acceleration and slope) and energy usage (measured directly at the battery terminals). Using this dataset, and through the adaptation of the vehicle specific power approach for quadricycles, it was possible to estimate electricity consumption with an absolute error between 1.4% and 4.5%. Due to the difficulties and risks associated to direct battery measurements of voltage and current of commercially available light-duty battery electric vehicles, this methodology was expanded and validated to this vehicle class in order to define the second-by-second electricity consumption as a function of the vehicle dynamics, based only on global recharging data per trip. The results obtained for two light-duty battery electric vehicles present similar accuracy and precision when compared to experimental results obtained for the electric quadricycles, with absolute deviations between 5.2% and 7.3%. The development of indirect methodologies to estimate the real-world on-road battery electric vehicle energy use in a prompt and simple way constitutes a powerful tool to evaluate the performance of these vehicles on any real-world trip. Exibir menos

Concerns with environmental impacts of urban mobility have led to the development of alternative solutions, such as battery electric vehicles (BEV), highly applicable to certain sectors namely in urban logistics, since BEV powertrain characteristics are extremely suited for urban driving context. This research work evaluates the adequacy of BEV in urban logistics in Lisbon, based on a real-world application. Vehicle second-by-second data was collected during regular operation of both the… Exibir mais

Concerns with environmental impacts of urban mobility have led to the development of alternative solutions, such as battery electric vehicles (BEV), highly applicable to certain sectors namely in urban logistics, since BEV powertrain characteristics are extremely suited for urban driving context. This research work evaluates the adequacy of BEV in urban logistics in Lisbon, based on a real-world application. Vehicle second-by-second data was collected during regular operation of both the internal combustion engine vehicle (ICEV) and the BEV (for 7 and 3 months respectively). The results demonstrate that BEV allows maintaining the same operation patterns, regarding the number of kilometers travelled per day (60 km), recharging time (6 h), and vehicle dynamics (average speed of 16 km/h for ICEV and 19 km/h for BEV). When comparing the energy impacts of shifting to electric mobility, the BEV allows reducing vehicle usage energy consumption by 76% and by 57% when considering the energy production stage. The logistics operations performance was not affected by the vehicle technology shift, since the operational requirements of the service were maintained and no issues on electric autonomy and recharging periods were observed, confirming the suitability of this vehicle technology for specific urban logistics applications. Exibir menos

Air quality in urban centers constitutes a challenge ahead for most cities. For this reason, the objective of this research work was to evaluate the impacts of changing traffic-related parameters on particulate matter (PM) concentration for several hierarchical street levels using real-world data for the city of Lisbon, Portugal. For that purpose, 2014 data regarding meteorological conditions, traffic volumes, typical vehicle speed, and a vehicle representative of the fleet was used in an air… Exibir mais

Air quality in urban centers constitutes a challenge ahead for most cities. For this reason, the objective of this research work was to evaluate the impacts of changing traffic-related parameters on particulate matter (PM) concentration for several hierarchical street levels using real-world data for the city of Lisbon, Portugal. For that purpose, 2014 data regarding meteorological conditions, traffic volumes, typical vehicle speed, and a vehicle representative of the fleet was used in an air quality dispersion model (CALINE4). The available data allowed building a baseline case for several streets that are representative of the traffic circulation conditions in Lisbon, which was compared with different scenarios: hypothetical introduction of a cordon toll (S1.1 to S1.4) and the implementation of a low emission zone (S2.1 and 2.2). The results indicate that reductions on PM2.5 concentrations from 5 to 42 % may be obtained from the implementation of the scenarios. Overall, this study demonstrates that modeling tools based on real-world data can provide a good approach to study urban policies regarding traffic-related PM exposure. Additionally, implementation of such measures requires an integrated strategy that enables proper enforcement and monitoring, as well as an adequate management of traffic flows between the implementation boundaries. Exibir menos

A method to perform the energy characterization of a vehicle according to the specific power required while driving was developed using public vehicle certification data. Using a portable emission measurement system, fuel consumption was quantified in a second-by-second basis under on-road conditions for 19 vehicles (spark-ignition, compression-ignition and hybrids). This data allowed building generic curves of fuel consumption as a function of the specific power, according to Vehicle Specific… Exibir mais

A method to perform the energy characterization of a vehicle according to the specific power required while driving was developed using public vehicle certification data. Using a portable emission measurement system, fuel consumption was quantified in a second-by-second basis under on-road conditions for 19 vehicles (spark-ignition, compression-ignition and hybrids). This data allowed building generic curves of fuel consumption as a function of the specific power, according to Vehicle Specific Power methodology. Comparing on-road measurements and the model estimates, a R2 higher than 0.9 for conventional and hybrid vehicles was obtained regarding modal fuel consumption. Comparing the fuel consumption measured on the drive cycles performed by each vehicle and the correspondent estimates, an absolute deviation of 9.2% ± 9.2% was found for conventional vehicles and 4.7% ± 1.8% for hybrids vehicles. This methodology was validated and applied to estimate the energy impacts of the best-selling vehicles in Portugal for different driving cycles. This prompt method, that does not require vehicle monitoring, can estimate curves of fuel consumption in g/s, as a function of specific power, which allows quantifying the absolute fuel use for any driving cycle. Exibir menos

The introduction of alternative vehicle technologies as a response to pressure regarding fossil fuel dependency in the transportation sector poses several questions regarding their impact on travel and driving behaviour and also on the environment. This project aims to assess electric vehicle users’ motivations, daily patterns and vehicle operation and management. Promoted by EMEL – Lisbon’s mobility and parking municipal company – the project was publicized among Lisbon’s electric vehicle… Exibir mais

The introduction of alternative vehicle technologies as a response to pressure regarding fossil fuel dependency in the transportation sector poses several questions regarding their impact on travel and driving behaviour and also on the environment. This project aims to assess electric vehicle users’ motivations, daily patterns and vehicle operation and management. Promoted by EMEL – Lisbon’s mobility and parking municipal company – the project was publicized among Lisbon’s electric vehicle users, who were offered, as an incentive, a green permit which allowed them to park the vehicles for free on the street within the city’s metropolitan central area.
Data were gathered over a period of one year from 25 users (private and fleet drivers) through interviews and on-board diaries, comprising a total of 5,132 trips, 49,785 km travelled and a total of 8,529 kWh charged related to 831 charges. The results indicate that environmental and economic (lower running costs) factors are the main drivers for electric vehicle adoption by private users, whereas fleet drivers mention their company’s image as the motive behind the deployment of this technology in fleets. Private users’ energy consumption and CO2 emissions were also estimated. When compared to conventional internal combustion engine vehicles running on gasoline or diesel, electric vehicles reveal considerable reductions in both energy consumption and CO2 emissions in a Well-to-Wheel life cycle approach. These decreases are between 35–43% for energy consumption and 58–63% for CO2 emissions. Exibir menos

The objective of this study was to characterize mobility patterns and compare the potential application of fully or partially electric propulsion vehicles in two different Portuguese contexts: the Lisbon region (city pattern) and the Island of São Miguel, Azores, Portugal (rural pattern). This characterization was performed by on road monitoring of 9 drivers in Lisbon and 17 drivers in Sao Miguel. São Miguel drivers are those which have a more suitable pattern for using alternative vehicles… Exibir mais

The objective of this study was to characterize mobility patterns and compare the potential application of fully or partially electric propulsion vehicles in two different Portuguese contexts: the Lisbon region (city pattern) and the Island of São Miguel, Azores, Portugal (rural pattern). This characterization was performed by on road monitoring of 9 drivers in Lisbon and 17 drivers in Sao Miguel. São Miguel drivers are those which have a more suitable pattern for using alternative vehicles comparably to the Lisbon region, since they travel about 47% less than the Lisbon population (33 km daily compared to 62 km per day) and, consequently, having a charging time availability about 30% higher. The São Miguel population also has greater presence in lower vehicle specific power (VSP) modes, with an average speed 25% lower than the Lisbon population. São Miguel drivers present greater efficiency in electricity consumption per kilometer (25% more efficient) than the Lisbon sample. Finally, the impacts of using alternative vehicles were quantified, concluding that the alternative technologies would reduce the Well-to-Wheel (WTW) energy consumption per kilometer between 37% and 68%. Exibir menos

This research work consisted on the development of a methodology to assess the economic feasibility of deploying EV charging stations (Park-EV) by quantifying the tradeoff between economic and energy/environmental impacts for EV parking spaces deployment. This methodology was applied to 4 different cities (Lisbon, Madrid, Minneapolis and Manhattan), by evaluating the influence of parking premium, infrastructure cost and occupancy rates on the investment Net Present Value (NPV). The main… Exibir mais

This research work consisted on the development of a methodology to assess the economic feasibility of deploying EV charging stations (Park-EV) by quantifying the tradeoff between economic and energy/environmental impacts for EV parking spaces deployment. This methodology was applied to 4 different cities (Lisbon, Madrid, Minneapolis and Manhattan), by evaluating the influence of parking premium, infrastructure cost and occupancy rates on the investment Net Present Value (NPV). The main findings are that the maximization of the premium and the minimization of the equipment cost lead to higher NPV results. The NPV break-even for the cities considered is more “easily” reached for higher parking prices, namely in the case of Manhattan with the higher parking price profile. In terms of evaluating occupancy rates of the EV parking spaces, shifting from a low usage (LU) to a high usage (HU) scenario represented a reduction in the premium to obtain a NPV = 0 of approximately 14% for a 2500 € equipment cost, and, in the case of a zero equipment cost (e.g. financed by the city), a NPV = 0 was obtained with approximately a 2% reduction in the parking premium. Moreover, due to the use of electric mobility instead of the average conventional technologies, Well-to-Wheel (WTW) gains for Lisbon, Madrid, Minneapolis and Manhattan were estimated in 58%, 53%, 52% and 75% for energy consumption and 66%, 75%, 62% and 86% for CO2 emissions, respectively.
This research confirms that the success of deploying an EV charging stations infrastructure will be highly dependent on the price the user will have to pay, on the cost of the infrastructure deployed and on the adhesion of the EV users to this kind of infrastructure. These variables are not independent and, consequently, the coordination of public policies and private interest must be promoted in order to reach an optimal solution that does not result in prohibitive costs for the users. Exibir menos

The increase of fossil fuel demand raises concerns on availability of resources for future energy demand and on potential environmental impacts. Electric vehicles (EVs) appear as one alternative to shift from fossil fuels to renewable energy resources. This research work analyzes the benefits of the introduction of EVs in a small energy system, the Flores island, Azores, in terms of primary energy and CO2 emissions. Four scenarios were designed considering different penetration rates of EVs… Exibir mais

The increase of fossil fuel demand raises concerns on availability of resources for future energy demand and on potential environmental impacts. Electric vehicles (EVs) appear as one alternative to shift from fossil fuels to renewable energy resources. This research work analyzes the benefits of the introduction of EVs in a small energy system, the Flores island, Azores, in terms of primary energy and CO2 emissions. Four scenarios were designed considering different penetration rates of EVs (Low and High) and different time of recharging strategies (Fixed and Flexible). The high shares of RES in the electricity production system (60–62%) did not guarantee a significant use of RES for the recharging of EVs (10–40%), as the additional electricity required had to be produced mainly from the diesel generators. The flexible recharging strategies allowed doubling the share of RES in the recharging of the EVs when compared to fixed recharging, and consequently double the impact on the reduction of primary energy consumption and fossil fuels imports. While the reduction of primary energy ranged between 0.2% and 1.1%, for CO2 emissions there was a decrease between 0.3 and 1.7%, proving that EVs can help improve the sustainability of energy systems. Exibir menos

This paper evaluates the benefits of introducing electricity powered vehicles (EV) in one island of the Azores archipelago in Portugal, the island of Flores. A Life Cycle Analysis (LCA) for the road transportation sector including EV was performed and the EV impacts in the electricity grid were evaluated. Two scenarios considering the introduction of EV were considered (Scenarios 2 and 3 with a shift in the car stock in 2050 of 30% and 70% to EV) and compared to the baseline scenario (Scenario… Exibir mais

This paper evaluates the benefits of introducing electricity powered vehicles (EV) in one island of the Azores archipelago in Portugal, the island of Flores. A Life Cycle Analysis (LCA) for the road transportation sector including EV was performed and the EV impacts in the electricity grid were evaluated. Two scenarios considering the introduction of EV were considered (Scenarios 2 and 3 with a shift in the car stock in 2050 of 30% and 70% to EV) and compared to the baseline scenario (Scenario 1 with no EV penetration). The results show that, if no alternative solutions are adopted, the road transportation sector LCA energy consumption will increase 58% in 2050, compared to 2009. In the most attractive scenario studied regarding EV integration in Flores, the LCA energy consumption in 2050 decreases by 34% and CO2 emissions by 39%, when comparing with Scenario 1. Moreover, the island’s electricity network is ready for EV arrival, at least until 2020. Thereafter, a smart charging scheme should be implemented to manage the vehicles’ energy demand according to the network technical limitations and the presence of Renewable Energy Sources (RES) should be reinforced, to decrease the island’s dependency on fossil fuels and, consequently, CO2 emissions. Exibir menos

This study presents a methodology to develop scenarios of evolution from 2010 to 2050, for energy consumption and emissions (CO2, HC, CO, NOx, PM) of the road transportation sector (light-duty and heavy-duty vehicles). The methodology is applied to Portugal and results are analyzed in a life-cycle perspective. A BAU trend and 5 additional scenarios are explored: Policy-based (Portuguese political targets considered); Liquid fuels-based (dependency on liquid fuels and no deployment of… Exibir mais

This study presents a methodology to develop scenarios of evolution from 2010 to 2050, for energy consumption and emissions (CO2, HC, CO, NOx, PM) of the road transportation sector (light-duty and heavy-duty vehicles). The methodology is applied to Portugal and results are analyzed in a life-cycle perspective. A BAU trend and 5 additional scenarios are explored: Policy-based (Portuguese political targets considered); Liquid fuels-based (dependency on liquid fuels and no deployment of alternative refueling infrastructure); Diversified (introduction of a wide diversity of alternative vehicle technology/energy sources); Electricity vision (deployment of a wide spread electricity recharging infrastructure); Hydrogen pathway (a broad hydrogen refueling infrastructure is deployed). Total life-cycle energy consumption could decrease between 2 and 66% in 2050 relatively to 2010, while CO2 emissions will decrease between 7 and 73% in 2050 relatively to 2010. In 2050 the BAU scenario remains 30% above the 1990 level for energy consumption and CO2 emissions; the other considered scenarios lead to 4 to 29% reductions for energy consumption and 10 to 33% for CO2 emissions in 2050 compared to the BAU. Therefore, alternative vehicle technologies are required in the long-term, but changes in taxation and alternative transportation modes policies are crucial for achieving short-term impacts. Exibir menos

This paper presents a study undertaken to understand the plug-in vehicle acceptance and probable utilization behaviour in terms of charging habits and utility factor (probability of driving in electrical mode). A survey was designed to be answered via World Wide Web, throughout 3 months and only accessible to Portuguese inhabitants. The survey was composed by biographical and car ownership info, mobility patterns, awareness toward plug-in vehicle technologies, price premium and, finally… Exibir mais

This paper presents a study undertaken to understand the plug-in vehicle acceptance and probable utilization behaviour in terms of charging habits and utility factor (probability of driving in electrical mode). A survey was designed to be answered via World Wide Web, throughout 3 months and only accessible to Portuguese inhabitants. The survey was composed by biographical and car ownership info, mobility patterns, awareness toward plug-in vehicle technologies, price premium and, finally, potential buyer’s attitudes regarding charging vehicles with electricity from the grid. An explanation of how each vehicle technology works in the case of a regular hybrid (HEV), a plug-in hybrid (PHEV) and a pure electric vehicle (EV) was provided. A total sample of 809 volunteers answered the survey, aged above 18 years old, 50% male and 50% female. The results allowed the estimation of the typical daily driving distance, the Utility Factor curve for plug-in hybrid future users, the charging preferences for future users of pure electric or plug-in hybrid vehicles and the necessary feebates to promote the market penetration of such technologies. Other correlations were also analyzed between driving patterns, type of owned car, price premium and the willingness to buy pure electric and plug-in hybrid vehicles. The main policy implications are that an increase of awareness campaigns is necessary if the government intends to support the plug-in electric vehicle technology widespread and a minimum of 5000 € investment per ton of avoided CO2 will be necessary in a year. Exibir menos

This paper presents a Life Cycle Analysis for these vehicles in terms of energy consumption and CO2 emissions, focusing on the impacts of alternative vehicle technologies for the Taxi, combining the fuel life cycle (Tank-to-Wheel and Well-to-Tank) and vehicle materials Cradle-to-Grave.
An internal combustion engine diesel taxi was used as the reference vehicle for the currently available technology. This is compared to battery and fuel cell vehicle configurations. Accordingly, the following… Exibir mais

This paper presents a Life Cycle Analysis for these vehicles in terms of energy consumption and CO2 emissions, focusing on the impacts of alternative vehicle technologies for the Taxi, combining the fuel life cycle (Tank-to-Wheel and Well-to-Tank) and vehicle materials Cradle-to-Grave.
An internal combustion engine diesel taxi was used as the reference vehicle for the currently available technology. This is compared to battery and fuel cell vehicle configurations. Accordingly, the following energy pathways are compared: diesel, electricity and hydrogen (derived from natural gas steam reforming).
Full Life Cycle Analysis, using the PCO-CENEX drive cycle, (derived from actual London Taxi drive cycles) shows that the fuel cell powered vehicle configurations have lower energy consumption (4.34 MJ/km) and CO2 emissions (235 g/km) than both the ICE Diesel (9.54 MJ/km and 738 g/km) and the battery electric vehicle (5.81 MJ/km and 269 g/km). Exibir menos

The main objective of this research is to analyze the impact of the market share increase of hydrogen based road vehicles in terms of energy consumption and CO2, on today's Portuguese light-duty fleet. Actual yearly values of energy consumption and emissions were estimated using COPERT software: 167112 TJ of fossil fuel energy, 12213 kton of CO2 emission and 141 kton of CO, 20 kton of HC, 46 kton of NOx and 3 kton of PM. These values represent 20–40% of countries total emissions. Additionally… Exibir mais

The main objective of this research is to analyze the impact of the market share increase of hydrogen based road vehicles in terms of energy consumption and CO2, on today's Portuguese light-duty fleet. Actual yearly values of energy consumption and emissions were estimated using COPERT software: 167112 TJ of fossil fuel energy, 12213 kton of CO2 emission and 141 kton of CO, 20 kton of HC, 46 kton of NOx and 3 kton of PM. These values represent 20–40% of countries total emissions. Additionally to base fleet, three scenarios of introduction of 10–30% fuel cell vehicles including plug-in hybrids configurations were analysed. Considering the scenarios of increasing hydrogen based vehicles penetration, up to 10% life cycle energy consumption reduction can be obtained if hydrogen from centralized natural gas reforming is considered. Full life cycle CO2 emissions can also be reduced up to 20% in these scenarios, while local pollutants reach up to 85% reductions. For the purpose of estimating road vehicle technologies energy consumption and CO2 emissions in a full life cycle perspective, fuel cell, conventional full hybrids and hybrid plug-in technologies were considered with diesel, gasoline, hydrogen and biofuel blends. Energy consumption values were estimated in a real road driving cycle and with ADVISOR software. Materials cradle-to-grave life cycle was estimated using GREET database adapted to Europe electric mix. The main conclusions on CO2 full life cycle analysis is that light-duty vehicles using fuel cell propulsion technology are highly dependent on hydrogen production pathway. The worst scenario for the current Portuguese and European electric mix is hydrogen produced from on-site electrolysis (in the refuelling stations). In this case full life cycle CO2 is 270 g/km against 190 g/km for conventional Diesel vehicle, for a typical 150,000 km useful life. Exibir menos

This work reports the use of near infrared (NIR) spectroscopy to determine some important biodiesel properties: the iodine value, the cold filter plugging point, the kinematic viscosity at 40 °C and the density at 15 °C. Principal component analysis was used to perform a qualitative analysis of the spectra and partial least squares regression to develop the calibration models between analytical and spectral data. The results support that NIR spectroscopy, in combination with multivariate… Exibir mais

This work reports the use of near infrared (NIR) spectroscopy to determine some important biodiesel properties: the iodine value, the cold filter plugging point, the kinematic viscosity at 40 °C and the density at 15 °C. Principal component analysis was used to perform a qualitative analysis of the spectra and partial least squares regression to develop the calibration models between analytical and spectral data. The results support that NIR spectroscopy, in combination with multivariate calibration, is a promising technique applied to biodiesel quality control, in both laboratory and industrial-scale samples. Exibir menos

This work reports the use of near infrared (NIR) spectroscopy to determine the esters content in biodiesel as well as the content in linolenic acid methyl esters (C18:3) in industrial and laboratory-scale biodiesel samples. Furthermore, calibration models for myristic (C14:0), palmitic (C16:0), stearic (C18:0), oleic (C18:1), linoleic (C18:2) acid methyl esters were also obtained. Principal component analysis was used for the qualitative analysis of the spectra, while partial least squares… Exibir mais

This work reports the use of near infrared (NIR) spectroscopy to determine the esters content in biodiesel as well as the content in linolenic acid methyl esters (C18:3) in industrial and laboratory-scale biodiesel samples. Furthermore, calibration models for myristic (C14:0), palmitic (C16:0), stearic (C18:0), oleic (C18:1), linoleic (C18:2) acid methyl esters were also obtained. Principal component analysis was used for the qualitative analysis of the spectra, while partial least squares regression was used to develop the calibration models between analytical and spectral data. The results confirm that NIR spectroscopy, in combination with multivariate calibration, is a promising technique to assess the biodiesel quality control in both laboratory-scale and industrial scale samples. Exibir menos

Biodiesel is produced mainly by a transesterification reaction which involves the reaction of vegetable oils, animal fats or waste oils with an alcohol (such as methanol) in the presence of a catalyst (such as sodium hydroxide or methoxide). Since the presence of contaminants can cause severe engine problems, the assessment of the biodiesel quality is very important. This work reports the use of near infrared (NIR) spectroscopy to determine the content of water and methanol in industrial and… Exibir mais

Biodiesel is produced mainly by a transesterification reaction which involves the reaction of vegetable oils, animal fats or waste oils with an alcohol (such as methanol) in the presence of a catalyst (such as sodium hydroxide or methoxide). Since the presence of contaminants can cause severe engine problems, the assessment of the biodiesel quality is very important. This work reports the use of near infrared (NIR) spectroscopy to determine the content of water and methanol in industrial and laboratory-scale biodiesel samples. A qualitative analysis of the spectra by principal components analysis was carried out and partial least squares regression was used to develop calibration models between spectral and analytical data. The results indicate that the use of NIR spectroscopy, in combination with multivariate calibration, is a promising technique to assess the biodiesel quality in both laboratory-scale and industrial-scale samples. Exibir menos

The transesterification of vegetable oils, animal fats or waste oils with an alcohol (such as methanol) in the presence of a homogeneous catalyst (sodium hydroxide or methoxyde) is commonly used to produce biodiesel. The quality control of the final product is an important issue and near infrared (NIR) spectroscopy recently appears as an appealing alternative to the conventional analytical methods. The use of NIR spectroscopy for this purpose first involves the development of calibration models… Exibir mais

The transesterification of vegetable oils, animal fats or waste oils with an alcohol (such as methanol) in the presence of a homogeneous catalyst (sodium hydroxide or methoxyde) is commonly used to produce biodiesel. The quality control of the final product is an important issue and near infrared (NIR) spectroscopy recently appears as an appealing alternative to the conventional analytical methods. The use of NIR spectroscopy for this purpose first involves the development of calibration models to relate the near infrared spectrum of biodiesel with the analytical data. The type of pre-processing technique applied to the data prior to the development of calibration may greatly influence the performance of the model. This work analyses the effect of some commonly used pre-processing techniques applied prior to partial least squares (PLS) and principal components regressions (PCR) in the quality of the calibration models developed to relate the near infrared spectrum of biodiesel and its content of methanol and water. The results confirm the importance of testing various pre-processing techniques. For the water content, the smaller validation and prediction errors were obtained by a combination of a second order Savitsky-Golay derivative followed by mean centring prior to PLS and PCR, whereas for methanol calibration the best results were obtained with a first order Savitsky-Golay derivative plus mean centring followed by the orthogonal signal correction. Exibir menos

This research work addresses the comparison of trip dynamics, energy consumption, CO2 and NOx Well-to-Wheel impacts of 5 transportation alternatives (conventional and electric bicycles, conventional and electric vehicles and an urban bus) in Lisbon, Portugal. On-road monitoring of a specific route in Lisbon revealed that bikers using electric bicycles increased their average speed between 8% and 26% compared to their use of the conventional bicycle, especially in the route sections with… Exibir mais

This research work addresses the comparison of trip dynamics, energy consumption, CO2 and NOx Well-to-Wheel impacts of 5 transportation alternatives (conventional and electric bicycles, conventional and electric vehicles and an urban bus) in Lisbon, Portugal. On-road monitoring of a specific route in Lisbon revealed that bikers using electric bicycles increased their average speed between 8% and 26% compared to their use of the conventional bicycle, especially in the route sections with positive slopes (up to 49% increases). Electric bicycles result in a Tank-to-Wheel energy consumption of 0.028 MJ/km, allowing an average autonomy of 46 km between recharging. When comparing the 5 transportation alternatives, the electric bicycles presented a higher travel time of 13.5%, 1.9% and 7.8% over the bus, low powered electric vehicle, and standard electric vehicle/conventional technologies, respectively. Regarding the Well-to-Wheel energy consumption analysis, the results indicated that, when compared to the other transportation solutions, the electric bicycle only uses 11%, 3%, 1%, 2% and 4% of the energy required when using the low powered electric vehicle, standard electric vehicle, conventional gasoline and diesel technologies and bus, respectively. Furthermore, the analysis of Well-to-Wheel emissions reveals that the electric bicycle has 13% and 4% lower CO2 emissions and 12% and 4% lower NOx emissions when compared to the low powered and standard electric vehicles, respectively. This research work allows sustaining that bicycles can be considered interesting solutions for urban trips, with comparable trip times to other transportation modes, as well as zero local emissions and reduced Well-to-Wheel pollutant impacts, contributing significantly for the improvement of the overall urban air quality. Exibir menos

This work’s aim was to quantify the energy consumption, the trip travel and the driving dynamics on specific routes in Lisbon, Portugal. Six electric and conventional bicycles and motorcycles were monitored, and a methodology to quantify the power required in each driving second was developed: Motorcycle and Bicycle Specific Power (MSP and BSP respectively). MSP and BSP allows characterizing energy consumption rates based on on-road data and to define real-world operation patterns (driving… Exibir mais

This work’s aim was to quantify the energy consumption, the trip travel and the driving dynamics on specific routes in Lisbon, Portugal. Six electric and conventional bicycles and motorcycles were monitored, and a methodology to quantify the power required in each driving second was developed: Motorcycle and Bicycle Specific Power (MSP and BSP respectively). MSP and BSP allows characterizing energy consumption rates based on on-road data and to define real-world operation patterns (driving power distribution), as well as to benchmark the different propulsion technologies under the same baseline of specific power. For negative MSP and BSP modes, the conventional and the electric motorcycles and bicycles demonstrated a similar pattern. However, their behavior was different for positive modes, since electric technologies allow reaching higher power conditions. The methodology developed estimates accurately the energy consumption (average deviation of −0.19 ± 6.76% for motorcycles and of 1.41 ± 8.91% for bicycles). The MSP and BSP methodologies were tested in 2 Lisbon routes. For the electric motorcycle an increase in trip time (+36%) was observed when compared to the conventional one, while for the electric bicycle a 9.5% decrease was verified when compared to the conventional one. The Tank-to-Wheel (TTW) energy consumption for motorcycles was reduced by 61% when shifting to electric mobility, while a 30% Well-to-Wheel (WTW) reduction is obtained. For the electric bicycles, an additional energy use is quantified due to the battery electricity consumption. Exibir menos

This paper aims at assessing the impacts of on-board devices that provide real-time feedback and eco driving training on bus drivers’ behavior. Rodoviária de Lisboa S.A., a Portuguese bus passenger-transport company, uses since 2008 a data logger and a managing software platform, GISFROT, developed by the company, to collect real-time operation data and to identify undesirable driving behaviors. These devices indicate to the driver undesirable driving behavior events through a sound signal… Exibir mais

This paper aims at assessing the impacts of on-board devices that provide real-time feedback and eco driving training on bus drivers’ behavior. Rodoviária de Lisboa S.A., a Portuguese bus passenger-transport company, uses since 2008 a data logger and a managing software platform, GISFROT, developed by the company, to collect real-time operation data and to identify undesirable driving behaviors. These devices indicate to the driver undesirable driving behavior events through a sound signal. Drivers also participate in annual in class training sessions on eco-driving techniques. The device is currently installed in 100 buses and approximately 600 drivers use these vehicles under regular daily operation, while driving in the Lisbon metropolitan area. An analysis of data collected from 2010 to 2013 was performed to characterize driving behavior of the sample of drivers. Two monitoring periods, a first one with sound feedback followed by a period without sound feedback, were considered. A comparison between periods was performed regarding the percentage of times drivers were in undesirable driving events such as hard brakes and hard accelerations, among others. This analysis also considered drivers characteristics (age and time working at company) and vehicle characteristics (bus age and type). The comparison between monitoring periods indicates that without sound feedback, inexperienced drivers and senior drivers tend to increase percentage of time in undesirable events, particularly when driving mini buses and articulated buses. These increases are mainly observable in extreme brakes and accelerations and hard stops, with rises between 8% and 291%. Exibir menos