ERCOT increasingly meets rising demand with solar, wind, and batteries
Note: This data set shows demand in the electric power industry only. ERCOT=Electric Reliability Council of Texas
Since 2021, electricity demand within the Texas electricity grid operated by the Electric Reliability Council of Texas (ERCOT) has steadily increased. In the first nine months of 2025, electricity demand in ERCOT, which manages about 90% of the state's load, reached a record high compared with the same period in previous years. Over those same months, ERCOT had the fastest electricity demand growth among U.S. electricity grids between 2024 and 2025. From January through September 2025, demand for electric power in ERCOT increased 5% compared with the same period in 2024 to 372 terawatthours (TWh), 23% more than the same months in 2021. Since 2023, wind and solar generation, especially utility-scale solar, have been the fastest-growing sources of electricity in ERCOT and are increasingly meeting rising demand.
Utility-scale solar generated 45 TWh of electricity in the first nine months of 2025, 50% more than the same period in 2024 and nearly four times more than the same period in 2021, when utility-scale solar only produced 11 TWh. Wind generation through the first nine months of this year totaled 87 TWh, up 4% compared with the same period in 2024 and 36% since the same period in 2021. Together, wind and solar generation met 36% of ERCOT’s electricity demand in the first nine months of 2025.
Note: The other category includes nuclear, hydroelectric, biomass, batteries, and other nonrenewable sources. ERCOT=Electric Reliability Council of Texas
Natural gas-fired generation also increased after 2021 but flattened more recently. Natural gas-fired generation between January and September increased to 161 TWh in 2023, 24% more than the same period in 2021. Since 2023, natural gas-fired generation remained relatively flat, totaling 158 TWh between January and September 2025. Although it is still the largest source of electricity for ERCOT, natural gas-fired generation averaged 43% in the first nine months of 2025, compared with 47% in the first nine months of 2023 and 2024.
The types of energy sources used for electricity generation can vary on an hourly basis, especially during the summer. Solar output is highest during midday hours, and the increased availability of solar generation in ERCOT in recent years has reduced the need for natural gas-fired generation during that time of the day. Solar generators in ERCOT produced an average of 24 gigawatts (GW) between noon and 1:00 p.m. during the summer months of June through September compared with an average of 12 GW of solar generation at noon in the summer months of 2023. Over the same period, the share of natural gas-fired generation at midday fell from 50% in 2023 to 37% in 2025.
Note: The other category includes nuclear, hydroelectric, biomass, batteries (for 2021 and 2023), and other nonrenewable sources. Summer=June, July, August, and September hourly values for each year; ERCOT=Electric Reliability Council of Texas
Batteries store electricity during daytime when generation from wind and solar is the highest, and they supply electricity when generation from wind and solar is declining. Beginning in October 2024, ERCOT began reporting battery output separately in its hourly grid data. In the summer months of 2025, batteries helped supply electricity in the evening as solar output declined, supplying an average of 4 GW in the 8:00 p.m. hour.
ERCOT’s electricity demand is forecast to grow faster than that of any other grid operator in the United States through at least 2026. In our October Short-Term Energy Outlook, we forecast demand will rise another 14% in the first nine months of 2026 compared with the same period this year, reaching 425 TWh.
Principal contributors: Kimberly Peterson, Tyler Hodge