It’s getting easier and cheaper to turn sunlight into electricity. The big question now is what to do with a power source that turns the current system on its head.
In Colorado, Xcel Energy will spend $4 million trying to answer that question by installing special batteries around Stapleton, which has one of Denver’s highest concentrations of rooftop solar panels.
Currently, power from those panels returns straight to Xcel’s larger electricity grid.
As part of the project, Xcel will deploy six “utility-scale” units this fall along its main power line for North Central Park and Eastbridge. The batteries will grab electricity from the panels and store it until it’s most needed, rather than giving it up to the grid.
“More and more people want to have solar, and more and more people want to have renewable energy. We want to be sure we’re able to manage that,” said Michelle Aguayo, a spokeswoman for Xcel Energy.
The batteries will reduce the amount of returning electricity that Xcel has to fit on its lines. If that solar power stays in the neighborhood, Xcel may be able to avoid costly upgrades to the power lines to Stapleton.
In the bigger picture, batteries may better equip Xcel to handle the spikes in demand that happen when, for example, all of Stapleton’s air conditioners activate on a summer afternoon. Batteries can concentrate the slow, steady flow of solar power into strategic spurts.
Xcel’s project is novel, but it’s on the small end of what this technology may soon do. In Los Angeles, a utility hopes that a “mega-battery” will serve tens of thousands of homes for hours during usage spikes, potentially replacing an entire gas power plant within five years.
Xcel also will be testing in-home batteries at individual residences this spring, to be provided by Sunverge Energy.
The company Northern Reliability will provide the larger utility batteries.
Xcel also will be testing a utility-scale solar array and battery system at the Panasonic “aerotropolis” near DIA, which will be capable both of operating as an independent micro-grid and of connecting to the regional grid.
Overall, Xcel hopes to better handle spikes in demand, drive down energy costs and accommodate more solar generators on its system.