Western U.S. hourly electric power supply: August 9-15, 2026
Grand Coulee Dam on the Columbia River in eastern Washington State, United States.
> photo by Adam Jones, Ph.D., CC BY-SA 3.0, via Wikimedia Commons - October 10, 2009.
more information
Grand Coulee Dam History
U.S. Bureau of Reclamation
by Allyn Svoboda
August 31, 2026
U.S. Energy Information Administration (EIA) Hourly Electric Grid Monitor is the data source for this report. The data is “preliminary.” EIA disclaimer is at the end of this report.
Charts below created from Hourly Grid Monitor data for Northwest, Southwest and California regions. These regions comprise the U.S Western electric system interconnection.
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[above charts]
U.S. Western Interconnection electric generation from all energy sources: August 9-15, 2026. Linecurrents.live charts, U.S. Energy Information Administration (EIA) Hourly Electric Grid Monitor data.
Natural gas combustion, hydroelectric dams and solar energy contributed the largest individual shares of electric generation in the Western Interconnection for the week beginning August 9, 2026.
| 39.1% | natural gas | |
| 15.8% | hydroelectric | |
| 15.0% | solar + solar w/storage | |
| 11.0% | coal | |
| 9.4% | wind | |
| 7.4% | nuclear | |
| 1.2% | geothermal | |
| 1.0% | other | |
| 0.1% | petroleum |
Non-combustion energy sources - Wind, Solar, Nuclear, Geothermal, Hydroelectric and Other - combined supplied:
MegaWatt-hours (Mwhr)
8,235,537
% total electric power generated
49.72%
Hourly electric generation by type for each day
DAILY 24-HOUR CHARTS below for the week beginning August 9, 2026 show hourly results for:
U.S. Energy Information Administration (EIA) non-combustion electric generating categories - color areas.
total of all electric energy sources, including combustion -gray line.
Linecurrents.live charts created from U.S. Energy Information Administration (EIA) data.
DAILY TRENDS
24-hour charts above reveal patterns:
Windpower production is less during mid’-day hours, but increases in late afternoon
Hydroelectric increases in early evenings to compensate for loss of solar generation and the evening increase in electric consumers’ demand.
MAXIMUMS and MINIMUMS
Mega-Watthours per Hour
systemwide
132,147 maximum
72,410 minimum
non-combustion sources
Hydroelectric
25,587 maximum
10,540 minimum
Solar + Solar with storage
39,969 maximum
Wind
15,292 maximum
2,620 minimum
Nuclear
7,325 maximum
7,138 minimum
Geothermal
1,229 maximum
1,091 minimum
Notes
Disclaimer: The information submitted by reporting entities is preliminary data and is made available "as-is" by EIA. Neither EIA nor reporting entities are responsible for reliance on the data for any specific use.
Standalone battery energy is not shown in this report because:
battery energy storage systems (BESS) do not generate (produce) electricity.
hourly values are negative (-) when absorbing power from other electric generating sources delivered by the electric transmission or distribution system, and positive (+) when releasing stored energy.
Solar with co-located battery systems is included in this report because the solar portion is a generating source. Battery charging from on-site solar may deduct electric supply during daylight hours, and be released during evening, overnight and early morning hours. Net electric flow is negative at times, similar to standalone batteries charging.