How much money does balcony solar save per year?

Savings depend on energy used at home as it is generated and the marginal per-kWh price you avoid. The state comparison and calculator use the same hourly-derived model; results are planning estimates.

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

Our $700 reference kit has 800 W of panels and an 800 W inverter, vertical south-facing panels, no additional shade and a constant 300 W household load. Modeled simple payback ranges from 2.7 to 6.7 years across states with signed plug-in legislation. This is a comparison of fixed scenarios; actual savings and permission to install depend on your home and local rules.

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 signed plug-in solar laws, including those not yet in effect. Facing and shade affect the hourly production and self-use. Run your own numbers.

Higher electricity prices can shorten payback, but production and household use also matter. Green bars identify signed legislation, including laws with future dates or conditions. Financial estimates do not establish permission to connect a system.

The math in four steps

Production. Typical-year hourly weather is converted to sunlight on the selected panel angle, then DC output with temperature and fixed losses, then AC output with inverter efficiency and clipping.
Self-use. For every modeled hour, use the smaller of AC production and constant household load. Unused output has zero export value in this model.
Savings. Self-used kWh × the marginal price per kWh you avoid. State averages are a default; fixed charges can make that default overstate savings.
Simple payback. Total upfront cost ÷ first-year savings. Include any electrical and mounting work in your cost.

Why self-use matters so much

At a 300 W constant load, this 800 W reference kit uses 80% of its generation at home.

Baltimore, Maryland: PVGIS ERA5 typical year, 800 W panels and inverter, vertical south-facing mount, no additional shade. Each point uses the same production model as the calculator, with a constant load and no export credit. Actual hourly consumption varies.

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

With the same reference inputs, our model estimates $194 per year for vertical south-facing panels in Portland, Maine, and $239 when tilted 35°. Different location, mounting, tariff and consumption assumptions can produce different estimates; these are scenarios rather than promised savings.

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.