In Arizona, a home builder has found a solution to the problem of solar panels generating the most power when it is needed the least. JLC Online reports:

One production builder in Arizona has come up with a workaround that looks like a win for all sides, including builders, homeowners, power companies—and the environment. Prescott, Ariz., builder Mandalay Homes, in partnership with German battery supplier Sonnen, has broken ground on Mountain View, a 323-home development where each house will have a solar array on the roof and a power-storage battery bank in the garage. And rather than be either a threat or a burden to the local utilities, the community’s “solar plus storage” setup will help the power company solve its own difficulties with managing Arizona’s sharp daily swings in energy supply and demand.

The homes in Mountain View will generate about 80% of the power they need, on an annual basis, says Mandalay chief technology officer Geoff Ferrell, and they will qualify for a federal tax credit to offset part of the cost of the solar and battery investment. But unlike solar-equipped homes that don’t have batteries, these battery-equipped homes won’t pump excess power production into the grid during sunny periods when the roof is making electricity, but nobody is home to use it—times when the utility already has more electricity than it can easily handle. Instead, each home’s panels will charge up its own batteries every day, using the home’s own extra solar power. Later in the day, when the utility is struggling to meet its daily peak service demand, the house will stop pulling power from the grid and instead supply its needs from the battery bank. Rather than being part of the problem, these solar-powered houses will be part of the solution.

In return, Arizona Public Service (APS) has agreed to give homeowners a reduced electric rate—as long as the house keeps its side of the bargain by “going dark” (from the utility’s point of view) from 3 to 8 p.m., the crucial peak-demand period. That reduced rate more than pays for the cost to finance the solar-plus-battery system that makes the whole strategy work.

Read more: ARIZONA’S MANDALAY ADOPTS GRID-OPTIMIZED SOLAR-AND-BATTERY SYSTEMS