Below are the tax credits and other incentives we could identify at the time of publication. Check www.dsireusa.org for an up-to-date list.

Federal tax credit: Uncle Sam will let you deduct 30 percent of what you paid for panels, equipment, installation, and permits from your tax bill. The current credit is in place through 2019; in 2020, the credit declines to 26 percent; then 22 percent in 2021; from 2022 on, it stabilizes at 10 percent. For more details on how to compute the credit, see the IRS's Q&A on Tax Credits for Sections 25C and 25D.

Net metering: When your solar energy system produces electricity you don’t use, it’s pushed onto the grid, and your utility pays you for it in the form of a credit against the electricity you’ll buy when you need more power than your panels can produce. Keep in mind, however, that few solar energy systems in this area over the course of a year produce more total electricity than needed by their houses.

Rebates: The state offers a rebate to ComEd customers that’s tied to the size of the system. It pays $1,500 per kilowatt, capped at 25 percent of total costs or $10,000, whichever is less.

Solar renewable energy certificates (SRECs): Illinois has just begun a program that pays you for the electricity your solar energy system produces; the certificates currently pay an average of about $170 per megawatt hour.

Property tax exemption: It’s not a straight exemption, but once you report the installation of your system to the local assessor’s office it will value it at an amount no greater than the dollar figure it would assign to a conventional HVAC system, and then exempt that increased amount from property taxes.