Eclipse 2024: What Happened to Solar Generation Across New York?

Professionals from our forecasting and operations teams began examining the eclipse’s potential effects on solar energy production months ago using solar forecasting tools, which anticipate how much solar energy production the system can expect throughout the day. This data helps our team determine what resources are needed to meet expected demand. If unexpected circumstances arise and solar resources aren’t producing power as initially forecasted, the NYISO’s operations team must dispatch energy from other resources to maintain reliability.

​In the hours leading up to the eclipse, solar resources generated just over 3,000 MWs. As the eclipse crossed New York, solar generation declined to just under 600 MWs by 3:30 pm, an 80% reduction. By 4 p.m., solar generation ramped back up to just under 1,200 MWs before declining again during the early evening hours.

NYISO’s operators maintained system reliability through a sharp decline in solar generation, with actual generation levels landing close to pre-eclipse forecasts. Flexible resources like electricity from hydro-pumped storage, conventional hydro facilities, and fossil-fuel resources were dispatched to make up for the reduced solar generation during the event.

As solar capacity continues to expand in the coming years, new challenges for our forecasting and operations teams will also grow. Continued collaboration with stakeholders, technological innovations, and investment in additional dispatchable resources and transmission infrastructure will help our team keep the lights on ― even when the sun doesn’t shine.