Visitors entering a code-locked central control room at Green Mountain Power (GMP)’s Colchester, Vt., headquarters instinctively lower their voices, whispering in deference to operators relaying orders from behind semicircular clusters of screens. It’s an intimidating space; one side of the black-walled room is taken up by a display showing a sprawling, yellow-lit maze of connections and symbols: a map of electricity flowing across the local grid. Technicians here have the daunting job of managing that vast, interconnected network; controlling hundreds of breaker switches; monitoring solar and hydroelectric electrical output; and anticipating energy demand spikes to keep Vermont’s lights on. When there’s an outage, these operators help coordinate the painstaking work of bringing the system back online.
Decarbonizing the U.S. electrical system is not as simple as replacing every fossil-fuel-burning power station with a wind farm or a solar field. Unlike coal and natural gas, renewable resources are intermittent—meaning they don’t work when the wind doesn’t blow or the sun doesn’t shine. A major shift to renewables will require electric grids to be reconstructed to account for those limitations, a massive and costly undertaking. National leaders have made plenty of pledges to address both emissions and resilience, but have been slow to implement real-world solutions. Lately, Green Mountain Power and other forward-thinking power companies have begun bridging that gap, piloting the complex systemwide reconstruction and engineering workarounds necessary to create a reliable, carbon-free power grid before it’s too late.
Rural Panton, Vt., is home to GMP’s newest effort to remake the electric system: a “microgrid” attached to a solar power plant, which can distribute its electricity to parts of the nearby community in case they get cut off from the main energy network due to falling trees or heavy snows, common occurrences in this isolated New England town. GMP engineers spent two years modeling electrical scenarios and testing components to make sure the system would work safely. “I can come up with 10,000 reasons why you wouldn’t pursue this,” says Josh Castonguay, VP of engineering and innovation at GMP, standing near a 4.9-megawatt storage battery that helps power the grid when the sun isn’t shining, and which doubles as a local energy supply for the town in an emergency. “This won’t work. That won’t work. They’re all things that you’ve just gotta engineer through.” When activated this month, the Panton system will become the first U.S. utility-built community microgrid able to run on renewable energy without a fossil-fuel backup.