ERCOT solar generation output doubles, continues to have most US wind output

Solar generation output doubled in the Electric Reliability Council of Texas in fourth quarter 2020 to 21.6 GWh, as Southwest Power Pool had the biggest change in its fuel mix as total renewables jumped 13 percentage points from Q3 to nearly 40% of the total fuel mix for Q4.

The Bonneville Power Administration continues to have the most total renewables market share at 80.3% of its total fuel mix, up 4.4 percentage points year on year, thanks to hydro generation that accounts for 72.5% of the fuel mix, according to BPA data.

Wind generation

Texas leads the nation in total renewable capacity, including wind, solar and battery energy, at 38.573 GW in Q4, thanks to 33.133 GW in installed wind capacity, according to the American Clean Power Q4 2020 market report. Texas also has 5.3 GW of solar capacity and 134 MW of battery storage, both second in the US.

ERCOT has the most wind output among the nation's grid operators at 252.4 GWh in Q4, up 17% year on year, according to ERCOT data. The grid operator also leads in total renewable output for Q4 at 274,597 GWh, an increase of nearly 21% from Q4 2020.

ERCOT currently has 25.121 GW of commercially operable wind capacity, ERCOT spokeswoman Leslie Sopko told Platts in a Feb. 8 email. Another 6.26 GW of new wind capacity has been synchronized to the grid for testing before it is commercially operable.

Five of top 10 states for wind capacity fall in the SPP footprint, according to ACP.

"SPP has seen a steady growth in wind over the last decade, and we don't anticipate that trend ending anytime soon," SPP spokeswoman Meghan Sever told S&P Global Platts in a Feb. 8 email. "With our members building more wind, solar and storage projects and closing traditional generation plants, renewables will continue to lead SPP's generation mix."

SPP set a record in 2020 as the first US independent system operator or regional transmission organization to have wind generation lead its fuel stack at 32%. For Q4, SPP had the largest market share of wind across the US at 36.6% of its total fuel mix, up about 3 points year on year, according to SPP data.

"We're able to reliably integrate record amounts of wind because of our history of prioritizing a diverse fuel mix and working with our members to build a strong transmission system capable of delivering renewable energy across our footprint," Sever said. "We are confident in our ability to reliably manage our growing renewable energy, and we expect to see more and more renewable records set as our generation mix evolves."

SPP had 27 GW of wind capacity at the end of 2020 with 4.092 GW scheduled to be in commercial operation by the end of 2021, however, that number could still change, according to SPP.

Solar generation

ERCOT solar generation output doubled year on year to 21.6 GWh in Q4, according to ERCOT data.

"We continue to see significant growth in new generation resources in the ERCOT region, especially utility-scale solar," Sopko said. "Of the more than 146,000 MW of new capacity currently under study in ERCOT, nearly 90,000 MW is for utility-scale solar projects."

ERCOT currently has 3.854 GW of commercially operable utility-scale solar and another 2.222 GW of utility-scale solar has been synchronized to the grid and is undergoing testing before it becomes commercially operable, Sopko added.

Solar output increased in every region except the California Independent System Operator. However, Cal-ISO continues to lead the US in solar output at 64.8 GWh in Q4, down 10% year on year, according to ISO data. The ISO also leads in solar market share at 11.07% of its total fuel mix in Q4, even as total renewables slipped about 6 percentage points to almost 28% of the total fuel mix in Q4.

Cal-ISO has 14.07 GW of installed solar, according to its December Key Statistics report.

"The California ISO is working to implement the state's renewable energy objectives and supports the state's leadership in a worldwide movement to decarbonize the electric sector," Cal-ISO spokeswoman Anne Gonzales told Platts Feb. 8 in an email. "The ISO stands ready to integrate additional renewable energy resources onto the grid, while maintaining safety, cost effectiveness and reliability."

California state leads the nation in installed utility-scale solar capacity at 13.23 GW, nearly triple any other state and accounting for nearly 30% of all solar capacity in the US, according to ACP. The state added 1.726 GW of solar in 2020, behind only Texas at 2.852 GW installed.

California also leads the nation in battery energy capacity at 876 MW, according to ACP. Although 34 states have some level of battery energy, only three states have more than 100 MW of storage,

The only states without installed solar are Alaska, New Hampshire, North Dakota and West Virginia. Meanwhile, there are 10 states without any wind capacity, mostly in the southeast.