Can you go off-grid with solar in Illinois?

We found no Illinois law requiring a home to connect to the utility grid. Building and occupancy rules are set locally, though, and counties regulate construction in unincorporated areas differently, so check with your village or county building and zoning office before you plan an off-grid home.

Because winter output drops sharply. A December or January month often produces only about a third of what a June month does, even though Illinois panels average about 1,200 kWh per kW over a full year near Chicago. A grid-tied home banks summer surplus as bill credits for winter. An off-grid home has no bank, so it has to be sized for the darkest weeks of the year.

Off-grid designers commonly size batteries for several days without sun, and most off-grid systems include a backup generator for long cloudy stretches. See solar in an Illinois winter.

The grid-tied system also earns the utility rebate and Illinois Shines, bringing our estimate to about $10,800, and a battery can earn about $4,050 back through the storage rebate. See what a home battery costs.

• The utility solar rebate. Illinois law pays the $300/kW rebate only for systems interconnected to the utility's distribution system.
• Bill credits for exports. Net metering, which credits surplus power at the supply rate for systems connected since 2025, requires a grid connection.
• The battery rebate. The storage rebate is paid for batteries enrolled in the utility's virtual power plant, which needs a connection.
• A backup source. Without the grid, the generator is your only fallback.

What you'd save is mainly the fixed monthly charges. The Citizens Utility Board put Ameren's 2026 customer and meter charges at about $14.51 a month combined.

Pair grid-tied solar with a battery and a backup panel. Standard solar shuts off during an outage for line workers' safety, but a battery system can disconnect from the grid and run your chosen circuits as an island, then recharge from the panels each day. You keep the rebates and bill credits, and the grid covers the winter shortfall.

See does solar work in a power outage? and whole-home vs. essentials backup.

• A remote cabin or outbuilding where running a utility line would cost more than the system.
• Seasonal or light use, such as a summer cabin that doesn't need winter power.
• A personal choice where independence matters more than cost.

For a year-round family home on ComEd or Ameren lines, grid-tied solar with a battery almost always costs less. Get a free quote to compare both for your home.