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BALCONY SOLAR KITSUNITED STATES

Balcony solar calculator

Should you buy balcony solar? Estimate what a plug-in system could produce where you live, how much of it your home would actually use, and how long it takes to pay for itself.

Published by ChoiscoLast verified

System size (panel watts)
W(check the kit's AC rating and your state's cap)
Who is home during the day?
Fine-tune home use

Starting rate: California residential average, January to July 2026 (year to date) (U.S. EIA). Use the number on your own bill if you know it. Exports start at $0 because most plug-in setups are not paid for power sent to the grid. The $1,000 price is only an example.

Your estimated balcony solar result

800 W in California, facing south

Loading sunshine data...

California rules

Law signed Sept. 30, 2026; starts Jan. 1, 2027. Up to 1,200 W per home; system must be certified as plug-in solar.

Read the California details
What this estimate assumes
  • Sunshine: PVGIS 5.3 (European Commission Joint Research Centre), long-run average for your state's Census 2020 center of population, with 14% system losses.
  • Hour-by-hour shape: one real weather year (2020) from PVGIS on your local clock (daylight saving included), scaled to the long-run yearly total.
  • Shade: we cut output by 15% for "some shade" and 40% for "heavy shade". These are our rough figures, not measurements.
  • Home use: 150 W running all the time (fridge, router, standby), plus 150 W or 350 W between 9am and 5pm if someone is home. Change these if you know your own numbers.
  • Output above the inverter limit is lost (clipped).
  • No battery, no price increases, no panel aging, no tax credits.
  • Fit labels are ours: up to 6 years is strong, up to 10 is borderline, longer is poor.

Sunshine data built 2026-10-02. Full method: research methodology.

Why most balcony solar savings estimates are too high

A plug-in system only saves money on power your home uses at the moment the panels make it. In most states, power that flows back out to the grid from a plug-in system earns nothing. So the most important question is not how sunny it is: it is whether something in your home is running while the sun is out.

That is why this calculator works through a full year one hour at a time, using sunshine data for your state from the European Commission's PVGIS tool. Our starting assumption is 150 watts running around the clock (a fridge, a router, devices on standby). Output above what your home is using at that moment flows out to the grid. If you know your own numbers, change them under the inputs.

What changes the answer most

  • Your electricity rate. At California's rates, the same panel saves more than twice what it saves in a low-price state.
  • Daytime use. Working from home, or running a dishwasher or laundry at midday, uses more solar directly.
  • Direction and mounting. A vertical panel on a south-facing railing makes noticeably less than an angled one; east and west lose more; north rarely makes sense.
  • System price. U.S. kits currently cost much more than European ones. See current prices on the kit tracker.

Every assumption is listed under the result and on our methodology page.