Plug-in and balcony solar
Plug-in solar, often called balcony solar, is a small photovoltaic kit that connects to a home through a standard outlet instead of a permanent wiring job. Ten US states have now passed laws that exempt qualifying devices of roughly 1,200 watts from the utility interconnection process, starting with Utah in 2025. This section currently holds one guide, a dated table of the enacted laws read from the statutes, with a break-even price table for a small kit; more pages will be added as the laws and the safety standard settle.
The pages here keep legality and value apart on purpose. A law can make a device permissible and still leave it a poor purchase, because a kit of a few hundred watts only saves money on the electricity the household uses at the moment it is made, and several of the laws pay nothing for the rest. The state-law page is a dated table of enacted statutes with bill numbers, caps, notice duties and tenant provisions, each checked against the legislature's own text where it could be reached. It is the page to open first, because the rule in your state decides which of the other questions matter.
Two cautions apply throughout. Nothing here is legal or electrical advice: statutes, effective dates and certification requirements change, and a landlord, an association or a local building department can add conditions the state law does not mention. And no page assumes the federal residential clean energy credit, which the IRS states is not available for property placed in service after December 31, 2025. Cost examples carry their inputs on the page, and any comparison to rooftop solar uses the DOE Q1 2025 residential benchmark of $2.95 per watt DC as a comparison line, never as a price for a kit.
Every guide in this section
How to use this section
Start from the question that blocks you. If you are asking whether a kit is allowed where you live, open the dated table of enacted state laws. It lists each statute, the wattage cap, any notice duty to the utility and the safety standard the law names, and it separates laws already in force from those that start in 2027, as of October 23, 2026.
If the law in your state is settled and the question is whether the kit is worth buying, the same page prices a break-even point with every input printed, and the main solar cost guide shows the rooftop benchmark that such a kit should be compared against. A kit that cannot export for pay only saves money on power used while the sun is up, so the household load at midday matters more than the rated watts.
| Your question | What settles it | Start with |
|---|---|---|
| Is a plug-in kit legal in my state | The enacted statute and its effective date | Plug-in solar legal states |
| Do I have to tell my utility | The notice clause in the state law | Plug-in solar legal states |
| Can my landlord or association say no | Lease terms and governing documents | HOA solar rules |
| Will the kit keep power on in an outage | Whether grid-tied equipment stays energized | Solar in a power outage |
A kit and a rooftop system on one scale: price per watt
Rooftop solar is judged by a price per watt, and a plug-in kit can be judged the same way, which is the quickest test of whether a listing is reasonable. The arithmetic needs two inputs that this site prints beside every result: a production factor of 1,200 kWh per kW of panel a year, which is an example and not a measurement of your balcony, and the value of each kilowatt-hour the household actually uses. One watt of panel then makes 1.2 kWh a year, so over ten years it makes 12 kWh, and a kit repays itself in ten years only if its price per watt is no higher than 12 times the value of a kilowatt-hour.
The rooftop comparison line is the U.S. Department of Energy's Q1 2025 residential benchmark of $2.95 per watt DC (modeled market price for an 8 kW system, 2024 dollars, checked October 30, 2026), a national modeled figure that is a comparison line and not a quote. Run through the same production factor, a rooftop system at that price needs each kilowatt-hour to be worth about 24.6 cents to repay in ten years. A kit has no such threshold to cross, because it has no installer labor to pay for, but it has a ceiling of its own, shown below, and the ceiling falls fast when part of the output goes unused. No federal credit is in any figure, since it does not apply to systems placed in service after 2025.
| Value of each kWh used | Kit price ceiling if all output is used | Kit price ceiling if 70 percent is used | Rooftop line, for reference |
|---|---|---|---|
| 15 cents | $1.80 per watt | $1.26 per watt | $2.95 per watt needs 24.6 cents |
| 25 cents | $3.00 per watt | $2.10 per watt | $2.95 per watt needs 24.6 cents |
| 35 cents | $4.20 per watt | $2.94 per watt | $2.95 per watt needs 24.6 cents |
Read across a row and the point is plain. At 25 cents a kilowatt-hour, a kit that is used completely can cost as much per watt as the rooftop line, or slightly more, and still repay in ten years, but a kit that wastes 30 percent of its output has to cost $2.10 per watt or less. The single most useful thing to learn before buying is therefore how much of a small kit's output the home can use at midday, and the full table with dollar amounts for an 800 W kit is on the state-law page.
Questions this section does not answer, and where they live
A kit raises questions that belong to other topics on this site. Whether the panels keep a home running in an outage depends on how grid-tied equipment behaves when the line is dead, which the outage guide explains for rooftop systems and which applies to most plug-in devices as well. Whether a condominium or townhouse association can say no is a question of governing documents and state access law, covered in the HOA rules guide. Renters should start with the tenant provisions in the state-law table, since most rooftop programs, including those in the income-qualified programs guide, require owning the roof.
Because the laws are new, dates matter more here than in most sections. Every state entry on the state-law page carries the date it was checked, and several effective dates fall in 2027. Treat a statement about a state that is older than a few months as a reason to open the state's own legislature page, which the guide links for each act it could read.
Sources and verification
- IRS, Residential Clean Energy Credit. Checked October 23, 2026.
- Utah Legislature, H.B. 340 (2025), enrolled. Checked October 23, 2026.
- UL Solutions, plug-in solar certification announcement. Checked October 23, 2026.
- U.S. Department of Energy, Solar Photovoltaic System Cost Benchmarks (Q1 2025), residential $2.95 per watt DC. Checked October 30, 2026.