Solar on storage units? Here’s how Illinois is making it happen.

Illinois is putting solar panels on the roofs of Public Storage facilities, part of a plan for 60 such projects across the state. Ten are already online, including a 763-kilowatt array in Justice, a Chicago suburb, that started generating power in March. These are "community solar" projects, meaning you don't need panels on your own roof to benefit. Instead, households and small businesses can subscribe to a share of the power generated and get a credit on their electric bill.

This is part of a broader push in Illinois, which has more installed community solar capacity than any other state, including California. A 2016 state law created incentives for these projects, and a law passed last fall raised the size limit for qualifying projects from 2 megawatts to 10 megawatts. Most community solar in Illinois has gone on rural land or industrial sites, with only about a fifth built on rooftops so far, mostly in the Chicago area. Utility ComEd says it plans to have more than 400 community solar arrays running by the end of this year, with about 100 of those on rooftops.

For the Public Storage rooftop projects specifically, once complete they're expected to cover 5 million square feet of roof space, add 44 megawatts of solar capacity, and deliver $36 million in total savings for subscribers. If you live in Illinois, especially near Chicago, this means more chances to sign up for a community solar subscription without installing anything on your own home. Availability and savings will depend on which projects are accepting subscribers in your area.