Short answer
Nothing on its own. A plug-in kit feeds your home's wiring, and whatever is running at that moment uses its power first; the grid supplies the rest. Over a year, our 800 W kit made 580–890 kWh on a railing and 890–1,430 kWh on a patio in nine US cities. That's 0.9–2.3 times what a typical main fridge uses in a year, or at most 4–11 miles a day of EV driving. For air conditioning, timing decides: an upright railing kit makes little in June to August, so a running AC adds at most $0–$8 to its summer savings, against up to $25–$81 for a tilted patio kit. In a power cut the kit stops, so it can't run anything then.
A kit doesn't power one thing
A plug-in kit has no outlet of its own for an appliance. It plugs into a wall outlet and feeds your home's wiring, the same wiring the grid feeds. At any moment, whatever is switched on in your home uses the kit's power first, and the grid supplies whatever is left. If nothing is using it, the power goes out to the grid, which usually earns you nothing (what your meter does with it).
So the useful questions are how much a kit makes, when it makes it, and whether something is running at the same time. Our 800 W kit never puts out more than 800 W at once; an appliance that draws more takes the rest from the grid.
A year of output, next to what things use
The same 800 W kit facing south, upright on a railing and tilted 30° on a patio, in nine cities from Seattle to Miami. A typical main fridge uses 617 kWh a year (EIA's 2020 Residential Energy Consumption Survey). EV miles assume every kWh the kit made went into the car, at 37.1 kWh per 100 miles, so they're a ceiling.
| City | Railing (upright, 90°) | Patio (tilted 30°) | ||||
|---|---|---|---|---|---|---|
| kWh a year | Fridges | EV miles | kWh a year | Fridges | EV miles | |
| Seattle, WA | 580 | 0.9 | 1,570 | 890 | 1.4 | 2,410 |
| Minneapolis, MN | 810 | 1.3 | 2,180 | 1,100 | 1.8 | 2,970 |
| Burlington, VT | 730 | 1.2 | 1,960 | 1,010 | 1.6 | 2,720 |
| Boston, MA | 740 | 1.2 | 2,000 | 1,080 | 1.7 | 2,900 |
| New York, NY | 670 | 1.1 | 1,800 | 1,050 | 1.7 | 2,840 |
| Denver, CO | 890 | 1.4 | 2,390 | 1,320 | 2.1 | 3,540 |
| Los Angeles, CA | 790 | 1.3 | 2,140 | 1,370 | 2.2 | 3,680 |
| Phoenix, AZ | 860 | 1.4 | 2,310 | 1,430 | 2.3 | 3,860 |
| Miami, FL | 640 | 1.0 | 1,710 | 1,240 | 2.0 | 3,330 |
"Fridges" is the kit's year divided by a typical main fridge's year. Each city name opens its railing result page; the state opens that state's plug-in solar law.
Air conditioning: it comes down to timing
An air conditioner only uses the kit's power while both are running. In June to August, an upright railing kit makes little, because the high summer sun glances off upright panels; in most of our cities it made more in winter than in summer (see the months). What it does make in summer, the home's steady 150 W always-on load mostly uses already, so a running air conditioner has little left to take.
A panel tilted 30° faces the summer sun, so it made more from June to August than the railing kit in all nine cities, and much of it went to the grid for nothing. That is the power an air conditioner running at the same time could use instead. The last column is what it would be worth at the state's average rate, if the air conditioner took all of it.
| City | AC use a year | Railing (upright, 90°) | Patio (tilted 30°) | |||
|---|---|---|---|---|---|---|
| Made | To grid | Made | To grid | Worth up to | ||
| Seattle, WA | 1,514 | 150 | 50 | 330 | 180 | $26 |
| Minneapolis, MN | 1,728 | 150 | 40 | 340 | 190 | $31 |
| Burlington, VT | 1,136 | 140 | 30 | 310 | 170 | $40 |
| Boston, MA | 1,136 | 130 | 30 | 310 | 170 | $51 |
| New York, NY | 1,483 | 120 | 20 | 320 | 170 | $49 |
| Denver, CO | 1,396 | 130 | 30 | 360 | 210 | $35 |
| Los Angeles, CA | 1,514 | 110 | 10 | 390 | 240 | $81 |
| Phoenix, AZ | 4,276 | 110 | 10 | 370 | 220 | $34 |
| Miami, FL | 3,112 | 80 | 0 | 300 | 160 | $25 |
"AC use a year" is what homes with air conditioning used on it in the city's Census region in 2020 (EIA's 2020 Residential Energy Consumption Survey, table CE5.3a), not counting the separate fan of a central system. Homes in apartment buildings with 5 or more units used 1,175 kWh.
In Phoenix, where homes with air conditioning used the most of any region here (4,276 kWh a year), the railing kit made 110 kWh from June to August and the patio kit 370 kWh. Even the patio kit's whole summer is a small part of a year of cooling there. A kit trims the air conditioner's bill a little; it doesn't run it.
An electric car: only if it's home in the daytime
A car charging from an ordinary outlet uses the kit's power the same way as anything else: only while both are running. A car that's away at work all day gets none of it. If every kWh the kit made all year did go into the car, that would be 1,570–2,390 miles a year from a railing kit and 2,410–3,860 from a patio kit in our cities, or 4–11 miles a day.
For scale: homes that charged an EV at home used 2,363 kWh a year on it in EIA's 2020 survey. The efficiency we use, 37.1 kWh per 100 miles, is the median of the 321 model-year 2026 EV versions on fueleconomy.gov (checked ), measured at the wall, so charging losses are included. Each version counts once, not by how many were sold.
The fridge and everything always on
A fridge, a router and anything on standby run day and night, so they're always there to use the kit's output while the sun is up. That's why our calculator starts every home with a steady 150 W always-on load. Over a year the kit made 0.9–2.3 times what a typical main fridge uses, but a fridge draws only a little at a time. Around midday the kit can make more than the always-on load uses, and our results count the rest as sent to the grid: across a year, the railing kit's home used 50%–63% of its output and the patio kit's 38%–48%.
What a plug-in kit can't do
- Run anything in a power cut. The kit follows the grid's wave and must stop within 2 seconds when the grid goes down. Why it stops. For backup power you need a battery or generator with its own outlet; what a battery adds.
- Supply more than its inverter limit. At 800 W, it covers part of anything drawing more, and the grid supplies the rest.
- Store power for the evening. Without a battery, what nothing uses at the moment it's made goes to the grid.
See your own year
First your state's plug-in solar law, then your address, direction, tilt and rate, hour by hour, with what your home uses and sends to the grid.
What balcony solar can run: questions
Can a balcony solar kit run an air conditioner?
Not by itself. While the kit is making power, an air conditioner running at the same time uses that power first and takes the rest from the grid. How much it helps depends on the mount. Upright on a railing, the kit made only 80–150 kWh from June to August in our nine cities, and the home's always-on load used most of it. Tilted on a patio it made 300–390 kWh, and 160–240 kWh of that went to the grid for nothing, which an air conditioner running at the same time could use instead.
Can plug-in solar charge an electric car?
Only while the car is plugged in at home when the sun is up. Even if every kWh the kit made all year went into the car, that's 1,570–2,390 miles a year from a railing kit and 2,410–3,860 from a patio kit in our cities, 4–11 miles a day, at the median model-year 2026 EV's 37.1 kWh per 100 miles. Homes that charge an EV used 2,363 kWh a year on it in EIA's 2020 survey.
How much power does a balcony solar kit make?
Our 800 W kit facing south made 580–890 kWh a year upright on a railing and 890–1,430 kWh tilted 30° on a patio, across nine cities from Seattle to Miami. At any moment its output tops out at the 800 W inverter limit, so anything drawing more than that takes the rest from the grid.
Will balcony solar keep my fridge running in a power outage?
No. A plug-in kit follows the grid's wave and must stop sending power within 2 seconds when the grid goes down, so it can't power anything in an outage. Keeping a fridge running in an outage takes a battery or generator with its own outlet. Why the kit stops →
How much does a kit save on air conditioning in Phoenix?
Homes with air conditioning in the Mountain South region used 4,276 kWh a year on it in EIA's 2020 survey. Our 800 W kit in Phoenix made 110 kWh from June to August on a railing and 370 kWh on a patio. The patio kit sent 220 kWh of that to the grid; an air conditioner running at the same time would have used it, worth up to $34 at Arizona's average rate.
How we calculated this
Kit output is our calculator's own result, run Oct 16, 2026 through the same steps as a result page: NLR PVWatts v8 hourly output for each city, the 800 W inverter limit, a flat 150 W always-on load, no battery and no credit for power sent to the grid, split into months for our winter guide. "To grid" is the June to August output the always-on load didn't use, and "worth up to" prices it at the state's average residential rate from EIA. What a fridge, an air conditioner and EV charging use comes from EIA's 2020 Residential Energy Consumption Survey (June 2023, revised March 2024): averages per home that has each one, by Census region for air conditioning. The EV efficiency is from fueleconomy.gov's vehicle file. It's an estimate. Our full method.
General information, not financial advice.