Highlights: October 2022

• New 12-month electricity demand lows were set in the Midwest (MISO) and in Texas (ERCOT) on October 29.

• Wholesale natural gas and electricity prices fell considerably from September to October as temperatures cooled.

• Total U.S. coal stockpiles had a month-over-month increase of 9.9%, reaching 88 million tons in October 2022.

Key indicators

Western U.S. hydroelectric generation rises from a 20-year low during the 2021–22 water year

Data source: U.S. Energy Information Administration, Form EIA-923, Power Plant Operations Report .
Note: Data for 2022 are preliminary; all other data are final. Western U.S. is defined as the Pacific Contiguous and Mountain Census Divisions. A water year is based on the hydrological cycle that runs from October 1 through September 30.

Hydroelectric generation in the western United States increased significantly in the 2021–22 water year relative to the 20-year low it experienced during the 2020–21 water year. During the 2021–22 water year western U.S. hydroelectric generation stood at 161.6 million megawatthours (MWh), a 12.9% increase (18.5 million MWh) relative to the 2020–21 water year (143.1 million MWh). Western U.S. hydroelectric generation can be quite variable because it is heavily dependent on rain and snowpack patterns. Between the 2001–02 and 2019–21 water years, western U.S. hydroelectric ranged from a low of 152.4 million MWh (2014–15 water year) to 217.9 million MWh (2010–11 water year). We consider the western United States to be the Pacific Contiguous and Mountain Census Divisions. A water year is based on the water cycle; precipitation in the fall or early winter does not affect stream and river flows until the following spring and summer. This pattern is particularly true in the western United States.

The increase in western U.S. hydroelectric generation was fueled by increases in precipitation in both the Pacific Northwest and California in the 2021–22 water year relative to the 2020–21 water year. In the Pacific Northwest, according to data from National Oceanic and Atmospheric Administration’s Northwest River Forecast Center, precipitation was up in the Snake River, Upper and Middle Columbia Basins, Columbia River Main Stem, Western Washington basins, and Western Oregon basins. In California, according to the California Department of Water Resources, precipitation from the Northern Sierra 8-Station Index went from 24 inches in the 2020–21 water year to 43 inches in the 2021–22 water year, while precipitation for the San Joaquin 5-Station Index increased from 18.8 inches to 25.3 inches during the same time frame. However, even at the higher precipitation levels in the 2022–21 water year, many basins in the Pacific Northwest and California were still below normal levels.

Data source: U.S. Energy Information Administration, Form EIA-923, Power Plant Operations Report .
Note: Data for 2022 are preliminary; all other data are final. "Western U.S" is defined as the Pacific Contiguous and Mountain Census Divisions. A water year is based on the hydrological cycle that runs from October 1 through September 30.

The increase in western U.S. hydroelectric generation was driven by a 17.4% increase in hydroelectric generation in the Pacific Contiguous Census Division, rising from 112.9 million MWh in the 2020–21 water year to 132.6 million MWh in 2021–22. All three states in the Pacific Contiguous Division had increases—Washington (17.4%, or 19.7 million MWh), Oregon (17.3%, or 5.3 million MWh) and California (14.6%, or 2.2 million MWh). The Mountain Census Division, however, fell by 4%, decreasing from 30.3 million MWh in the 2020–21 water year to 29 million MWh in 2021–22. Although the two largest state generators, Montana (10 million MWh) and Idaho (8.6 million MWh), were essentially flat year over year, other states had decreases. Arizona’s generation decreased by 9.4%, and lower generation in other Mountain states—most notably, Nevada, where generation fell by 23.5%)—helped push total Mountain Division hydroelectric generation lower in the 2021–22 water year. Well-below-normal flow rates in the Lower Colorado River have also reduced hydroelectric generation in Arizona and Nevada.

These regional differences are evident at the plant level. In water year 2021–22, hydroelectric generation expanded by 19% (3.4 million MWh) for the Grand Coulee Dam in Washington, the largest hydroelectric generator in the Pacific Northwest, while generation fell by 10.0% (0.4 million MWh) for the Hoover Dam on the Arizona/Nevada border, the largest hydroelectric generator on the Lower Colorado River Basin.

• Principal Contributor:

• Name: Paul McArdle
  Email: [email protected]