Rooftop solar is chipping away at the accepted narratives on how to keep the electric grid reliable. The expansion of solar panels on New England roofs is helping keep the lights on during winter, rendering at least one fossil fuel power plant unnecessary, writes Benjamin Storrow. Rooftop solar’s knight-in-shining-armor debut comes amid a growing national debate over the growth of carbon-free power sources like wind and solar and their impact on the nation’s strained electric grid. Grid regulators have warned that as coal and natural gas plants retire in increasing numbers, large swaths of the country could face a heightened risk of blackouts during heat waves and winter storms. But the finding in New England is changing regulators’ view of rooftop solar, which has historically been dismissed as a small, unpredictable source of energy. “I think that the solar finding was just monumental because it’s not something that anyone that I know of had ever considered or put forward as part of the solution,” Philip Bartlett, chair of the Maine Public Utility Commission, told Ben. The influx of solar power also cleared a path for closing the Mystic Generating Station, one of New England’s dirtiest power plants. Customers have been paying a subsidy to keep the plant online after the grid operator said it was necessary to shore up the region’s power supply in cold weather. But now New England’s grid operator says the power plant is no longer needed to prevent blackouts, in part because of rooftop solar installations. That’s good news for the region’s twin goals of cutting planet-warming pollution and keeping the power on during cold, stormy winters. New England’s grid relies heavily on natural gas, which can be a problem in winter when much of the fuel is dedicated to heating homes and other buildings. That has led the region to use carbon-intensive oil as a backup power source. Rooftop solar, however, is easing the need for backup oil. The New England grid operator told federal regulators last week that the new solar, paired with incoming offshore wind power and flat energy demand, has better positioned the region to navigate the next four winters. That’s a stark contrast from recent winters, when the region’s grid struggled to keep up with demand. And it parallels something happening now in Texas, where solar power is helping fill the need for electricity during a devastating heat wave.
| 
