- A plug-in solar kit is one to four panels plus a microinverter that plugs into a standard outlet.
- The power it makes is used by whatever is running in your home at that moment, which lowers your bill.
- Typical kits are 400-1,200 W, cost $400-1,500 and save $80-350 a year depending on sun and electricity prices.
- It is legal in a growing number of places, including Germany, the UK and nine US states, with conditions.
Plug-in solar goes by many names: balcony solar, plug-and-play solar, portable solar, or the German Balkonkraftwerk (“balcony power plant”). They all describe the same idea. Instead of a roof-mounted system installed by professionals, you hang one or two panels on a railing, fence or patio, plug a cable into an outdoor outlet, and your home starts using free electricity from the sun.
In this article
What’s in the box
- Solar panels. Usually one or two modern panels of 300-450 W each. Some kits use lightweight, glass-free panels for balconies.
- A microinverter. Panels produce direct current (DC). The microinverter converts it to alternating current (AC) that matches your home’s electricity, and it switches off if the grid goes down.
- A cable with a plug. It connects the inverter to a standard outlet.
- Mounting hardware. Clamps or brackets for a railing, wall, fence or ground stand.
- Optional extras: a battery, a monitoring app, or a smart plug to measure output.
How it lowers your bill
Electricity takes the path of least resistance. When the kit is producing, say, 300 W and your fridge, router and TV are using 400 W, the solar power covers 300 W of that and the grid supplies only the remaining 100 W. Your meter records less consumption. You do not need to plug appliances into the solar panel; it feeds your whole circuit. We explain the details in how balcony solar works.
If the kit produces more than your home uses at that moment, the surplus flows back into the grid. In most plug-in laws you are not paid for that surplus, which is why size matters.
How much power does it make?
A lot less than a rooftop system, but not nothing. As a rough guide, each 100 W of panels produces 80-170 kWh a year depending on where you live and how the panels are mounted. An 800 W kit on a sunny, south-facing balcony in the US might make 700-1,100 kWh a year. That covers roughly 7-10% of a typical American home’s use, or much more of a small apartment’s. See how many kWh an 800 W kit produces for regional numbers.
What does it cost and save?
| Kit size | Typical price (2026) | Typical yearly savings |
|---|---|---|
| 360-400 W (1 panel) | $400-650 | $40-150 |
| 800 W (2 panels) | $800-1,300 | $90-300 |
| 1,200 W | $1,200-2,000 | $130-400 |
The spread is wide because savings depend mostly on your electricity price. In California or Connecticut, a kit can pay for itself in three to five years; in states with cheap power, it can take eight to ten. Use our savings calculator to get your own estimate.
Is it legal?
It depends where you live:
- Germany and much of Europe: yes, up to 800 W of inverter output, with simple registration in Germany.
- United Kingdom: yes, since 27 August 2026, up to 800 W with a compliant product. See UK rules.
- United States: nine states have laws, mostly allowing up to 1,200 W. Elsewhere, connecting to your home wiring technically needs utility approval. See our state tracker.
- Australia and Canada: not yet, though both are moving. See current rules.
Who is it for?
Plug-in solar makes the most sense if you:
- Rent, or live in an apartment or condo without roof access.
- Have a balcony, patio, yard or fence that gets at least four to five hours of direct sun.
- Pay a relatively high price for electricity.
- Have some steady daytime use, such as a fridge, working from home or air conditioning.
It makes less sense if your only outdoor space faces away from the sun and is shaded, or if you own a house with a good roof and could install a much larger, cheaper-per-watt rooftop system. We compare the two in plug-in vs rooftop solar.
Is it safe?
Certified kits are designed to be safe for household circuits: the inverter shuts down within a fraction of a second if unplugged or if the grid fails, and output is limited to protect wiring. The real risks come from shortcuts, such as extension cords, uncertified inverters, overloaded circuits or panels that are not properly secured against wind. Read is plug-in solar safe? before you buy.
Next steps
- Check whether it’s allowed where you live.
- Measure your space and note which way it faces.
- Estimate savings with the calculator.
- Compare kits in our buyer’s guide.