Quick Truck Study: FCEV vs BEV lifecycle CO2 emissions - PART 2
A few days ago I published my study Quick Truck Study: FCEV vs BEV lifecycle CO2 emissions on comparing BEV truck’s CO2 to FCEV trucks CO2, which has received a lot of attention. It found that the CO2 output over an average Class 8 truck mileage and life span (65,000 miles per year for 10 years) for BEV and FCEV trucks were very similar in a low emissions 40g/kWh grid.
One of the comments I received, from David Wenger, was that the Nikola H2 usage assumption may be a bit low.
As I was working through the cost and use case implications for my next study of heavy duty FCEV vs BEV, I found that Nikola’s lease numbers weren’t adding up to the 4.6kg/100km for H2 usage (a figure I thought to be optimistic). It turns out that 4.6kg/100km was an early Nikola assumption, and the revised number used in Nikola’s Prospectus is 7.5 miles /kg, or 8.33kg /100km, an 81% increase. Obviously, this will have a significant impact on the final results.
So, Part 2 of this study is a revision to correct an earlier mistake, fall on my sword as it were. All other assumptions and points made in the earlier study remain the same.
Here, we re-run the numbers again, using 8.33kg per 100km for Nikola.
SCENARIO 1 - Average km, very low electricity CO2
STEP 1 – USAGE EMISSIONS
Energy usage
Tesla - <125 kWh/100km (we'll use 125 kWh here)
Nikola – 8.33kg H2/100km (1kg H2 takes 61.2kWh) or 509.8kWh/100km (based on 7.5 miles per kg)
Assumed CO2 output per year (40g/kWh)
Tesla – (1.25kWh/km x 100,000)x 0.04kg CO2 = 5,000kg CO2 per year
Nikola – (5.098kWh/km x 100,000)x 0.04kg CO2 = 20,392kg CO2 per year
STEP 2 - EMBODIED EMISSIONS
Tesla Semi 500 mile - 1,000kWh battery (my assumption) – 83,000kg CO2
(Tesla Semi 300 mile - 600kW battery (my assumption) – 49,800kg CO2)
Nikola – 250kWh battery (Nikola staff) – 20,780kg CO2
STEP 3 - TOTAL – 10 year life-cycle (usage emissions + embodied emissions)
Tesla – 83,000kg embodied + (5,000kg x 10 years) = 133,000kg CO2
Nikola – 20,780kg embodies + (20,392kg x 10 years) = 224,698kg CO2
RESULT - Nikola One/Two has 69% HIGHER CO2 emissions than Tesla Semi at 40g CO2/kwh and 100,000km per year for 10 years in their lifecycle.
SCENARIO 2 - High km, very low electricity CO2
This time we'll take a high mileage usage pattern, typical of larger fleets, assuming 200,000km per year (125,000 miles per year)
Tesla – 83,000kg embodied + (10,000kg x 10 years) = 183,000kg CO2
Nikola – 20,780kg embodied + (40,784kg x 10 years) = 428,617kg CO2
RESULT - Nikola One/Two has 134% HIGHER life-cycle CO2 emissions than Tesla Semi at 40g CO2/kwh and 200,000km per year
SCENARIO 3 - Average km, average electricity CO2
At 400g CO/kWh and 100,000km /year, result is:
Tesla - 83,000kg embodied + (50,000kg x 10 years usage) = 583,000kg CO2
Nikola – 20,780kg embodied + (203,918kg x 10 years usage) = 2,059,964kg C02
RESULT - Nikola One/Two has 253% HIGHER life-cycle CO2 emissions than Tesla Semi at 400g CO2/kwh and 100,000km per year
SCENARIO 4 - Very low km, very low electricity CO2
We'll now assume that the truck does only about 50,000km (30,000 miles) per year, or about half that of average. It is rare that any business will have truck utilization this low.
Tesla - 83,000kg embodied + (2,500kg x 10 years usage) = 108,000kg CO2
Nikola – 20,780kg embodied + (10,195kg x 10 years usage) = 122,739kg C02
RESULT - Nikola One/Two has 14% HIGHER life-cycle CO2 emissions than Tesla Semi at 40g CO2/kwh and 50,000km per year
Obviously, with the new assumption from Nikola, the results are VERY different. Under EVERY scenario, the Tesla creates less lifetime CO2 than the Nikola truck. This climbs higher as the miles traveled increases, and the grid CO2 increases.
I'd now call lifetime CO2 emissions a big win for Tesla Semi
James Carter
Principal Consultant
Vision Mobility
Global Director of Marketing
4yFull presentation here on Hyliion: https://www.sec.gov/Archives/edgar/data/1759631/000121390020015311/ea123187ex99-3_tortoiseacq.htm
Global Director of Marketing
4yJames Carter Great research .... you may want to look into a new company competing in the same space - Hyliion - eliminates the carbon intensity and reduce the greenhouse gas emissions of commercial transportation Class 8 vehicles by being the leading provider of electrified powertrain solutions. https://www.hyliion.com/
Director at Chiltern Utility Solutions LTD
4yIf you were looking at "well to wheel" for the Nicola 1 you would not only need to look at the embodied emissions of fuel cell, and vehicle hydrilogen tank, but also the embodied emissions of the electrolyser, compressor, and tank infrastructure for the filling station + the electrolyser efficiency of around 80%. On the Tesla, you would need to take account of embodied emissions in the charger plus losses in the charging cycle. Together, I believe this would push things further in favour of Tesla. The only way I can think to significantly lower the emissions of Nicola one would be to use electricity which would otherwise be curtailed for the hydrogen production.