A rare annular solar eclipse is approaching, and the state’s largest power grid said it is prepared to meet energy demand despite a forecasted strain on solar power production.
During this Saturday’s celestial event known as the “Ring of Fire,” the moon will cover up to 80% of the sun over North Texas, said Ryan Bennett, the astronomy program director at University of North Texas. D-FW residents should not look at the eclipse without eye protection — sunglasses are not protective enough, and experts are advising people to purchase eclipse glasses online.
The last time an annular solar eclipse took place was roughly 11 years ago, similarly crossing the Southwest region, according to NASA. The next eclipse won’t happen until 2023, with Alaska the only state in its path.
While astronomers and star watchers alike are looking forward to the eclipse, some have concerns about how a lack of potential solar energy will affect the Electric Reliability Council of Texas grid and if any blackouts will occur as a result.
Last Thursday, ERCOT, which serves about 90% of Texas, issued a statement, saying the celestial event will impact the output of photovoltaic generation resources from about 10:15 a.m. to 1:40 p.m. Saturday.
PVGR refers to any equipment, including solar panels, that converts energy from the sun into electricity.
“ERCOT has planned for this forecasted reduced generation and expects grid conditions to be normal,” the energy operator said in a statement on X, the social media site formerly known as Twitter.
The grid operator said it is planning to use “ancillary services” or other energy resources to balance the needs of supply and demand during the eclipse.
Is this eclipse a test of the grid’s capabilities?
Some think the upcoming solar eclipse is a test of the grid’s abilities, especially after intense heat this summer. Triple-digit temperatures and unrelenting heat waves prompted many to crank up their cooling systems, causing the grid to rely heavily on solar power.
However, ERCOT says it has been working with solar vendors in advance to prepare for this event and does not expect any reliability concerns.
“They’ve known about and planned for the eclipse for months in advance, so there’s been plenty of time to get thermal plant and transmission maintenance scheduled and completed, to avoid forced [unexpected] outages,” said Alison Silverstein, an electric system reliability consultant and researcher.
Saturday morning’s eclipse is taking place during moderate fall weather, which is bringing seasonably cooler temperatures to ERCOT’s service area. Therefore, total demand on the grid is forecasted to be moderate due to minimal air conditioning usage, Silverstein added.
“Thermal and wind generation should be able to cover it without much need for solar generation,” she said.
The eclipse’s greatest impact on solar power energy will be at 11:50 a.m., when solar resources are expected to be reduced to 13%, according to a PowerPoint presentation from ERCOT shared at an August board meeting.
On Thursday, ERCOT’s six-day forecast shows supply temporarily dipping around midday Saturday at around 72,864 megawatts. But that number outpaces projected demand and ERCOT still expects to have ample supply throughout the weekend. Forecasts are updated about every hour on average.
