As I understand it, the US is mostly waiting for UL listing of equipment, which hasn't been a priority because no US locals have allowed them. With Utah and others starting to allow them, UL listing will likely come at some point (hopefully shortly) thereafter.
Not sure I quite get how this works from the wall plug PoV: if you have smart metering on your electricity, will it actually show you drawing less from the grid due to the input provided by the panels to your local wiring etc?
Or is that it actually goes back to the grid and you would pay your bill minus the amount you’ve fed back in?
You'd most likely need a different meter to get credit for power supplied to the grid. These are expected to locally offset current use, so you pull less power through the meter, any surplus generation is a gift to the grid.
To encourage adoption of plug in solar, at least in the US, it can offset your local consumption, but a smart meter doesn't credit power back that flows to the utility to your local distribution.
It is likely not going "back to the grid" unless you have the rest of your house shut down; where the "balcony solar" output is greater than your house usage. These systems are "back-feeding" into your circuits, and if you have it on a circuit that is less heavily loaded than the panels are providing, the other branch circuits are going to sop up that usage before it literally feeds back into the grid.
Huh! Where does this stand in the US? I’ve always heard it’s significantly risky to plug power-generation directly into a wall outlet (though you can do it in a pinch)
> 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-...
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.
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 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
Linemen will always ground a transmission line before doing any work on it, unless live work is authorized, and then other safeguards apply. They never assume a line is actually dead just because it's supposed to be dead; they always assume there might be a backfeed or other source of potential on the line.
The balcony solar rigs (at least the properly designed ones) don't energize the male connector until they detect that it's plugged in. And they de-energize it if the mains/utility power goes out.
> Incorporate partially insulated pins to prevent access to live conductive parts
> Incorporate non-rewireable moulded plug fitted with a BS 1362 fuse not exceeding 5A
And anti-islanding, so it disables when the grid isn't live.
Seems quite reasonable. Also, like, this is a thing balcony solar is being done in lots of regions of the world now. Based on those parts of the world not burning down, not electrocuting people at scale, this is ipso facto all just a sad tired lot of ridiculous FUD.
There is illegal, actively enforced illegal, and then there is 'your house burns down and insurance denies your claim because you didn't follow local laws' illegal
So it costs £400 and can shave up to £100 a year - how it was calculated?
In best case scenario you'll have to hang this thing off balcony for 4 years to break even. Will it be good after 4 years?
I cannot see the economics of that. If it shaves £50, then it's 8 years.
How long do they last? How much maintenance costs (cleaning etc.)
Sounds like a way to stuff the poor with copium device. The rich will get minted and government doesn't have to resolve the problem of expensive electricity for another election cycle.
As I understand it, the US is mostly waiting for UL listing of equipment, which hasn't been a priority because no US locals have allowed them. With Utah and others starting to allow them, UL listing will likely come at some point (hopefully shortly) thereafter.
There's this device: https://usa.apsystems.com/ez1-installers/
And also this: https://connectder.com/
State plug in solar legislation tracker: https://www.brightsaver.org/legislation-tracker
(passed in 10 state, 2 awaiting signatures, as of this comment)
Not sure I quite get how this works from the wall plug PoV: if you have smart metering on your electricity, will it actually show you drawing less from the grid due to the input provided by the panels to your local wiring etc?
Or is that it actually goes back to the grid and you would pay your bill minus the amount you’ve fed back in?
You'd most likely need a different meter to get credit for power supplied to the grid. These are expected to locally offset current use, so you pull less power through the meter, any surplus generation is a gift to the grid.
To encourage adoption of plug in solar, at least in the US, it can offset your local consumption, but a smart meter doesn't credit power back that flows to the utility to your local distribution.
It is likely not going "back to the grid" unless you have the rest of your house shut down; where the "balcony solar" output is greater than your house usage. These systems are "back-feeding" into your circuits, and if you have it on a circuit that is less heavily loaded than the panels are providing, the other branch circuits are going to sop up that usage before it literally feeds back into the grid.
Great! Just in time for winter!
Huh! Where does this stand in the US? I’ve always heard it’s significantly risky to plug power-generation directly into a wall outlet (though you can do it in a pinch)
> 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
> This can be mitigated by using systems that only feed in when they sense it’s connected to the grid
Which are the only ones that are legal.
Linemen will always ground a transmission line before doing any work on it, unless live work is authorized, and then other safeguards apply. They never assume a line is actually dead just because it's supposed to be dead; they always assume there might be a backfeed or other source of potential on the line.
The balcony solar rigs (at least the properly designed ones) don't energize the male connector until they detect that it's plugged in. And they de-energize it if the mains/utility power goes out.
Those risks are covered.
https://www.gov.uk/government/consultations/plug-in-solar
> Incorporate partially insulated pins to prevent access to live conductive parts
> Incorporate non-rewireable moulded plug fitted with a BS 1362 fuse not exceeding 5A
And anti-islanding, so it disables when the grid isn't live.
Seems quite reasonable. Also, like, this is a thing balcony solar is being done in lots of regions of the world now. Based on those parts of the world not burning down, not electrocuting people at scale, this is ipso facto all just a sad tired lot of ridiculous FUD.
U.K. wiring is obviously different
https://youtu.be/Na4LTD1M6nw
Seemed to cover a fair amount of the issues (or non issues)
https://www.utilitydive.com/news/virginia-legislature-passes...
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?
There is illegal, actively enforced illegal, and then there is 'your house burns down and insurance denies your claim because you didn't follow local laws' illegal
So it costs £400 and can shave up to £100 a year - how it was calculated? In best case scenario you'll have to hang this thing off balcony for 4 years to break even. Will it be good after 4 years? I cannot see the economics of that. If it shaves £50, then it's 8 years.
How long do they last? How much maintenance costs (cleaning etc.)
Sounds like a way to stuff the poor with copium device. The rich will get minted and government doesn't have to resolve the problem of expensive electricity for another election cycle.
Panels have 25+ year lives. Anything after the break even is free energy. There is no material maintenance cost.
Also, East and South facing apartments are about to see rent increases.