UK households free to install plug-in balcony solar panels from end of August

> I’ve always heard it’s significantly risky to plug power-generation directly into a wall outlet.

Depends on what is generating the power.

Traditional fuel-powered emergency generators are indeed risky, as they are designed to operate on their own. They do not need the grid to be present as they will generate their own sine wave. This means they'll happily feed power outside your house, and nothing is preventing you from getting a giant "bang" when external power is turned on again. For this kind of generators you need a way to XOR the two, usually with a physical interlock turning off the main incoming fuse before the generator fuse can be engaged.

Most solar panels, including those plug-in ones, are designed to operate with a grid present. They don't generate a sine wave, they just sense the incoming wave and "push back". Turn off the external power and they'll stop operating. So no power during an outage, but also no risk of electrocution.

With plug-in sources there's an additional risk, namely that something else on the same fuse can draw power from both the outside grid and from the additional source. The breaker in your mains panel will still trip at (say) 15A, but there's now a second thing supplying current. If that provide an additional 15A, some piece of equipment on that circuit can now draw 30A without tripping any breakers - and its plugs and wiring are not designed for 30A, so they'll catch fire. This has to be avoided by giving the power source its own dedicated hard-wired breaker. Or, in the case of those plug-in PV panels: limit their power to something which is unlikely to cause issues in practice. That 15A wiring isn't going to melt at 16A.

Bills are popping up in state legislatures across the United States to legalize plug-in solar. I wrote about a bill that was up for consideration here in Washington state earlier this year: https://www.brethorsting.com/blog/2026/01/washington-should-...

Unfortunately, the bill didn't make it over the finish line during the 2026 session. The Washington legislature only met for two months this year: https://www.brethorsting.com/blog/2026/01/how-the-washington...

I'm in Seattle, where we enjoy some of the cheapest electricity costs in the country thanks to abundant hydroelectric generation and a public, city-owned utility, but back-to-back 10% rate hikes were just announced for 2027 and 2028, and I hope that spurs our state legislature to take balcony solar more seriously.

Depends on power output.

Has been legal in Germany for some years but inverters have to be limited to 800W output so it doesn't overload the circut. Additionally, you're limited to 4 panels max 2000w peak total.

A lot of companies also offer batteries where the panels directly plug into and then into the wall. That way you're only feeding into your household when you're using it.

If you set it up correctly a lot of households manage to save up to 35% in electricity.

The US is a patchwork, but it is legal in some places, including Utah!

https://grist.org/buildings/balcony-solar-is-taking-state-le...

More in other links on my page too: https://www.earth.org.uk/note-on-G83-lite.html#sources

The main risk factor is people trying to pump too much juice into a wall socket rated for a lesser current. Plus the connector needs to be male - shock risk. The combination of live and male is not generally something you see in households and people may not register that it’s something outside of normal household risk profile.

That plus bit of risk of things being energised that say a lineman thought would be out. This can be mitigated by using systems that only feed in when they sense it’s connected to the grid

U.K. wiring is obviously different

https://youtu.be/Na4LTD1M6nw

Seemed to cover a fair amount of the issues (or non issues)

https://www.brightsaver.org/legislation-tracker has a beautiful day visualization map that shows state by state status!

The broader North East / New England is very far along!

Is plug-in solar explicitly illegal in most states?