How much money does balcony solar save per year?

In our reference scenario, an 800 W kit facing south saves about $100 to $260 a year in the states with plug-in laws, depending mostly on the local electricity price. Utah is at the low end, California at the high end.

Why doesn't a bigger kit always save more?

Plug-in systems generally earn nothing for power sent to the grid. Once the kit makes more than your home is using at that moment, the extra is wasted, so the last few hundred watts save less than the first.

Does balcony solar qualify for the federal tax credit?

We have not confirmed that any federal credit applies to plug-in kits. The federal residential clean energy credit ended for expenditures after 2025 under the July 2025 budget law, so do not count on a credit in your payback.

Is plug-in solar worth it? Payback by state for a balcony kit

For most people in the states that have legalized it, a south-facing 800 W balcony kit pays for itself in three to seven years. The two numbers that decide it are your electricity price and how much of the kit’s output your home actually uses. Panel brand matters far less.

Payback by state

Scenario: two 400 W panels on an 800 W microinverter, hanging vertically on a south-facing railing with open sky, a 300 W constant daytime load, a $700 kit, and each state's average 2026 residential price (EIA). Green bars mark states with a plug-in solar law. East- or west-facing railings take roughly 20–30% longer; shade takes longer still. Run your own numbers.

Among states with plug-in laws, California, Maine, New York, Connecticut and New Hampshire come out fastest because electricity there costs about 27 to 33 cents per kWh, according to the EIA’s 2026 data. Utah, with sunnier skies but prices near 13 cents, takes about seven years. Hawaii is the extreme case at over 46 cents, though it has no plug-in law yet.

The math in four steps

Production. Sun at your location × panel size × an orientation factor × system losses. A vertical, south-facing panel makes about 64 to 73 percent of what the same panel would make tilted at 20°, in our modeling for the states with plug-in laws.
Self-use. Only what you use at the moment it is produced counts. With a typical always-on load of a few hundred watts, an 800 W kit gets 80 percent or more used.
Savings. Self-used kWh × your price per kWh.
Payback. Kit cost ÷ yearly savings. Solar.com puts typical plug-in kits at $600 to $1,500; we use $700 for an 800 W kit.

Why self-use matters so much

Hourly model on typical-year weather (Greensboro, NC, 35° south-facing array). Assumes a constant background load and no credit for power sent to the grid, which matches the plug-in laws in Vermont and Maine. Real homes vary through the day, so treat this as a guide.

Vermont’s law says plug-in devices get no net metering and exported power is not compensated. Maryland’s regulator warns that some meters may count exported power as zero or add it to your usage. That makes the plug-in math different from rooftop solar: every kWh you send to the grid is worth nothing or less.

Practical consequences:

Size to your background load. Check your smart meter’s lowest daytime hourly reading, or add up what is always on (fridge, router, standby electronics, a dehumidifier).
Shift flexible use to midday. Run the dishwasher or charge an e-bike while the sun is up.
A battery only helps if it is cheap. It shifts midday surplus to the evening, but adds cost and another device to certify.

Comparing estimates

Maine’s Office of the Public Advocate estimated an 800 W system could save a household about $350 a year. Our model gives about $190 for Maine with vertical panels and about $245 if tilted on a stand. The gap comes mostly from mounting angle and self-use assumptions. We prefer a conservative estimate you can beat over a generous one that disappoints.

Run your own numbers

The calculator uses the same model with your state, facing, mounting, shade, kit size and price. For how the factors were derived, see our method and the orientation data.