I've looked into this extensively in the US, and there are three headaches from my POV:
1. Most states require special device certification by a "nationally recognized authority" that doesn't seem to fully exist yet. There ARE devices that would almost certainly GET certified, but aren't yet.
2. Ordering panels is a PITA. Most want to sell you either RV/Camping grade (overpriced), or in too large of quantities (e.g. 10x+). If you want to hit under 1,200 Watts meaning just 2x 600 Watt panels, well, nobody wants to ship that. Most popular panel vendors, don't want to sell single-panels, and you're looking at 500% markup for camping/RV style panels (with often worse performance, and proprietary connectors).
3. "Moveable" panel requirements. The laws frequently don't define what that means or what that looks like. It seems to want to essentially ban a small roof install, but stuff like ground-mounting (e.g. even just for the angle), or securing so they don't blow over, is ambiguous. Plus most laws don't exempt you from planning requirements, just utility requirements, so the local city/county can still fine you for your "install."
What I am saying is: I'm absolutely in love with plug-in solar, but unfortunately being an early adopter in the US is going to be annoying. I hope in ten years it will be almost turn-key, just buy a "kit" plug it in, and you're done.
Point 1 isn’t true anymore as of this week. The first UL3700 inverter from Hoymiles just got approved and is being sold by Bright Saver for consumers https://www.brightsaver.org/balcony-solar-kits
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.
If I understand the devices correctly, the current generation of microinverters should meet all power-limit requirements and disconnect if the grid goes away.
You’re correct, but states are looking for UL 3700 compliance, which extends current anti islanding inverter protection requirements to GFCI intelligence and circuit overload protection (you can overload the branch circuit without the breaker tripping, for example). Intelligent EV chargers support these protections, this is the generation version of protections mentioned.
There is near zero actual risk. These systems have been around for a long time and are widely deployed in Europe.
Circuit breakers have been around for a century and work great. You plug something in that pushes or pulls too much current and pop - disconnect.
So while they are absolutely safe, there's huge FUD coming from the utilities who lose revenue AND PROFIT they were getting from you with each system.
Pacific Gas and Electric, Southern California Edison, Florida Power & Light (FPL), Commonwealth Edison (ComEd), Consolidated Edison (ConEd) are all for profit monopolies.
Asking them if it's safe is like asking Microsoft if you should switch away from Word. It does not matter the reasoning, the answer was always going to be the same.
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?
In Uk, If an old (rare) mechanical meter the meter will go backwards, the ideal. If a dumb digital meter the meter will simply pause counting up. If a smartmeter again the import reading will pause but a separate export reading will count up, for which you get no credit or debit but its nice to know. Ideally as battery prices drop you end up buying a battery that soaks up any surplus for later and so you don't lose any back to the grid. If you pay up for a commercially installed solar you can get paid for what you export but with plug in solar you just give it away.
In the UK as a consumer you can (always AFAIK) get a smart meter for free, and your retail supplier is required to offer you a non-zero rate (the "Smart Export Guarantee") for what you export back to the grid. That can be as high as about half the rate to import.
You'd most likely need a different meter (and utility cooperation) 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.
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)
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.
> 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.
If people are interested, the magic word is "islanding" and the key technology you want which makes this stuff safe to deploy is thus "anti-islanding protection".
If your device discovers it has become an "island", generating power with no real grid (maybe there are two similar panels next door but not a 10GW power grid) it switches off. This is not only safer for you, it's also critical for repair people who might be fixing some overhead line miles away and then a dozen stupid devices inject lethal power onto a circuit their operator has assured them is dead - because from their end it was dead.
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.
Yeah I question the overall economics. I wonder if balcony solar is a net negative for the environment.
If you assume the cost of a thing can serve as a rough proxy for the energy inputs of the thing then until you meet RoI you're likely negative (environmentally speaking)
casual if the RoI for these is 4-8 years. and some stats[1] show most renters don't stay in one place that long. Given that the majority of people move at least once inside the RoI period, and may not move to somewhere with a balcony that can set up the solar it's possible that more of these system will end up in a landfill than actually help the environment.
which isn't to say I'm against deregulation here. I don't see any real reason to prevent people from being allowed to set them up so long as they're safe. and certainly some people will get great use out of them. but I also don't think they're as categorically great as they're made out to be.
4 years is a pretty good payback time, it's a pretty obvious investment if you can afford it, and it's pretty affordable (with the added bonus that if you're renting, you can take it with you). Solar panels tend to last a pretty long time, really the only worry is whether the manufacturer has cheaped out on the electronics (cleaning is literally going to be wiping it with a sponge once a year or so).
(Insulating your house or getting double glazing, for example, takes a lot longer to pay itself back, and these are pretty popular home improvements despite that and the higher outlay)
I see it more as a way for relatively well off people to do a little bit for the environment rather than any sort of solution of high energy prices for the poor. The nice thing, of course, is that the more people buy them, the cheaper electricity is for everyone else, so you're doing everyone else a small favour by having one.
I'll certainly be buying one, not because of the ROI/payback calculation, but just because it's fun to talk about with my kids and a nice thing to do.
Similarly, plug in batteries are on the way (see recently Octopus announcement). I'll probably buy one for the same reasons.
That said, the payback time also looks very favourable, especially relative to a full rooftop install, so you don't even need to be alturistic!
Do you account environmental impact of manufacturing of this device, shipping and energy used to place it in the store, time spent on customer service, people transporting it to their homes etc? How hanging it off balcony will offset that? Isn't that just virtue signalling?
Solar is cheap in terms of environmental impact and embodied energy as well. The balcony and plug-in part just makes the install cheap, which is by far the largest cost of residential solar.
I've looked into this extensively in the US, and there are three headaches from my POV:
1. Most states require special device certification by a "nationally recognized authority" that doesn't seem to fully exist yet. There ARE devices that would almost certainly GET certified, but aren't yet.
2. Ordering panels is a PITA. Most want to sell you either RV/Camping grade (overpriced), or in too large of quantities (e.g. 10x+). If you want to hit under 1,200 Watts meaning just 2x 600 Watt panels, well, nobody wants to ship that. Most popular panel vendors, don't want to sell single-panels, and you're looking at 500% markup for camping/RV style panels (with often worse performance, and proprietary connectors).
3. "Moveable" panel requirements. The laws frequently don't define what that means or what that looks like. It seems to want to essentially ban a small roof install, but stuff like ground-mounting (e.g. even just for the angle), or securing so they don't blow over, is ambiguous. Plus most laws don't exempt you from planning requirements, just utility requirements, so the local city/county can still fine you for your "install."
What I am saying is: I'm absolutely in love with plug-in solar, but unfortunately being an early adopter in the US is going to be annoying. I hope in ten years it will be almost turn-key, just buy a "kit" plug it in, and you're done.
Point 1 isn’t true anymore as of this week. The first UL3700 inverter from Hoymiles just got approved and is being sold by Bright Saver for consumers https://www.brightsaver.org/balcony-solar-kits
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/
Hoymiles just got UL3700 approved this week and sold by Bright Savers
If I understand the devices correctly, the current generation of microinverters should meet all power-limit requirements and disconnect if the grid goes away.
You’re correct, but states are looking for UL 3700 compliance, which extends current anti islanding inverter protection requirements to GFCI intelligence and circuit overload protection (you can overload the branch circuit without the breaker tripping, for example). Intelligent EV chargers support these protections, this is the generation version of protections mentioned.
https://electrek.co/2026/07/20/us-first-ul-3700-balcony-sola...
https://pluginsolarus.com/learn/ul-3700-safety-standard-expl...
https://permitpower.org/wp-content/uploads/sites/35/2026/01/...
https://www.cesa.org/wp-content/uploads/Plug-In-Solar.pdf
State plug in solar legislation tracker: https://www.brightsaver.org/legislation-tracker
(passed in 10 states, 2 awaiting signatures, as of this comment)
There is near zero actual risk. These systems have been around for a long time and are widely deployed in Europe.
Circuit breakers have been around for a century and work great. You plug something in that pushes or pulls too much current and pop - disconnect.
So while they are absolutely safe, there's huge FUD coming from the utilities who lose revenue AND PROFIT they were getting from you with each system.
Pacific Gas and Electric, Southern California Edison, Florida Power & Light (FPL), Commonwealth Edison (ComEd), Consolidated Edison (ConEd) are all for profit monopolies.
Asking them if it's safe is like asking Microsoft if you should switch away from Word. It does not matter the reasoning, the answer was always going to be the same.
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?
In Uk, If an old (rare) mechanical meter the meter will go backwards, the ideal. If a dumb digital meter the meter will simply pause counting up. If a smartmeter again the import reading will pause but a separate export reading will count up, for which you get no credit or debit but its nice to know. Ideally as battery prices drop you end up buying a battery that soaks up any surplus for later and so you don't lose any back to the grid. If you pay up for a commercially installed solar you can get paid for what you export but with plug in solar you just give it away.
In the UK as a consumer you can (always AFAIK) get a smart meter for free, and your retail supplier is required to offer you a non-zero rate (the "Smart Export Guarantee") for what you export back to the grid. That can be as high as about half the rate to import.
You'd most likely need a different meter (and utility cooperation) 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.
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)
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.
> 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.
If people are interested, the magic word is "islanding" and the key technology you want which makes this stuff safe to deploy is thus "anti-islanding protection".
If your device discovers it has become an "island", generating power with no real grid (maybe there are two similar panels next door but not a 10GW power grid) it switches off. This is not only safer for you, it's also critical for repair people who might be fixing some overhead line miles away and then a dozen stupid devices inject lethal power onto a circuit their operator has assured them is dead - because from their end it was dead.
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
https://www.utilitydive.com/news/virginia-legislature-passes...
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.
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.
> 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.
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?
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.
Yeah I question the overall economics. I wonder if balcony solar is a net negative for the environment.
If you assume the cost of a thing can serve as a rough proxy for the energy inputs of the thing then until you meet RoI you're likely negative (environmentally speaking)
casual if the RoI for these is 4-8 years. and some stats[1] show most renters don't stay in one place that long. Given that the majority of people move at least once inside the RoI period, and may not move to somewhere with a balcony that can set up the solar it's possible that more of these system will end up in a landfill than actually help the environment.
which isn't to say I'm against deregulation here. I don't see any real reason to prevent people from being allowed to set them up so long as they're safe. and certainly some people will get great use out of them. but I also don't think they're as categorically great as they're made out to be.
[1] https://www.redfin.com/news/renters-staying-put-longer/
4 years is a pretty good payback time, it's a pretty obvious investment if you can afford it, and it's pretty affordable (with the added bonus that if you're renting, you can take it with you). Solar panels tend to last a pretty long time, really the only worry is whether the manufacturer has cheaped out on the electronics (cleaning is literally going to be wiping it with a sponge once a year or so).
(Insulating your house or getting double glazing, for example, takes a lot longer to pay itself back, and these are pretty popular home improvements despite that and the higher outlay)
Can you explain why it is "pretty obvious investment"?
What else can you put your money into that will give you 25% a year?
https://magnifina.com/articles/rooftop-solar-yield/
I see it more as a way for relatively well off people to do a little bit for the environment rather than any sort of solution of high energy prices for the poor. The nice thing, of course, is that the more people buy them, the cheaper electricity is for everyone else, so you're doing everyone else a small favour by having one.
I'll certainly be buying one, not because of the ROI/payback calculation, but just because it's fun to talk about with my kids and a nice thing to do.
Similarly, plug in batteries are on the way (see recently Octopus announcement). I'll probably buy one for the same reasons.
That said, the payback time also looks very favourable, especially relative to a full rooftop install, so you don't even need to be alturistic!
Do you account environmental impact of manufacturing of this device, shipping and energy used to place it in the store, time spent on customer service, people transporting it to their homes etc? How hanging it off balcony will offset that? Isn't that just virtue signalling?
Solar is cheap in terms of environmental impact and embodied energy as well. The balcony and plug-in part just makes the install cheap, which is by far the largest cost of residential solar.
Panels have 25+ year lifetimes. Anything after the break even is free energy. There is no material maintenance cost.
You think a balcony solar panel is going to die after 4 years? Why? What makes it different from any other solar panel? They have lives in decades.
You're spouting tired anti-solar talking points. Again, why?
Also, East and South facing apartments are about to see rent increases.