August eclipse to test European, U.S. grids with solar ramps

A total solar eclipse crosses from Siberia over the Arctic, Greenland, and Iceland to northern Spain and Portugal on August 12, 2026 — the first total eclipse over mainland Europe since 1999. Most of Europe will see a deep partial eclipse in the early evening, while parts of the eastern U.S. and Quebec get a smaller partial eclipse around midday. If you have solar panels, you may notice a temporary dip in output during the event, but the size of that dip depends heavily on where you live and what time the eclipse happens locally.

For most of Spain, Portugal, France, and the UK, the eclipse hits late in the day when the sun is already low, so the actual loss of solar energy for the day is small, around 1%. Farther north and west, where the eclipse happens earlier relative to solar noon, the effect is bigger: Iceland could lose close to 3% of its daily sunlight, Greenland up to 6%. In the U.S., New York may lose about 2% of daily solar energy and Quebec 3-4%, since the eclipse there falls closer to midday.

This matters mainly for grid operators, not individual homeowners, since it affects how much backup power and storage utilities need to bring online as solar output dips and then recovers quickly. Germany, despite losing only about 1% of its daily solar energy, is expected to see the sharpest swing of any region studied, with generation needing to ramp back up fast after the eclipse passes. Homeowners with rooftop solar likely won't need to do anything differently, but may see a brief, temporary drop in their own panel output around the eclipse's peak time in their area.