32
votes
Tweaks to state laws mean many Americans will be able to benefit from small, simple plug-in solar panels
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- Title
- Power surge: law changes could soon bring balcony solar to millions across US
- Authors
- Oliver Milman
- Published
- Nov 30 2025
- Word count
- 805 words
I'm psyched for this to start to come online. I have rooftop solar, but it was installed professionally and I've filled up my roof.
As of yet, I don't want to install additional ground solar and tie it into my existing system while chasing an updated interconnection.
But if I could just start DIYing a small number of panels into my existing electrical system? Heck yeahhhhhh. I'd absolutely be doing that as weekend project-type territory. It'd be awesome to build a better winter buffer to last longer on all-local solar power.
This would be so cool living in a multifamily unit. I own my unit, but it's basically impossible to get a loan for solar on a multifamily roof with multiple owners, so rooftop solar even just for my portion of the roof is challenging to do. And then the HOA has to get involved because they manage the roof and sidings for the buildings.
But plugin solar panels? It would be SO EASY! No HOA involvement needed and easy to pay for out of pocket. And even a few hundred watts would satisfy a big chunk of my base load at least in summer when I have good sun over head on my back patio. Crossing my fingers to see this catch on nationally.
I agree! The number of triple deckers in my neck of the woods that could handle/host a couple panels on the railings is so promising.
It's one of those no-brainer changes to code and regulation that we'll look back on as frustrating for how long it took to become ubiquitous!
We live in an apartment and I would be so hype to be able to just plug in a solar panel and use that. PGE is getting insanely expensive and where we are in the Bay Area, we get more sunny days than not, so we could feasibly use solar with no issues.
So it just backfeeds to the outlet? What happens if you have it wired like: pannel with 15a breaker > outlet with solar > 30a load?
I'm not an electrician and I don't know how this is wired but I'd imagine this could be a safety concern unless I'm totally miss understanding this.
Death or injury to unsuspecting linemen is what happens. This is a common problem in wintery regions: people keep cheap generators and plug them in with a so-called "generator cable" (a DIY male-to-male cord, much like the evil Christmas light adapters) to power random stuff in their house.
That's not how these work. There are big inverters (I don't know what they're called) that handle lots of panels and work like you're describing, and there are micro inverters that handle only a couple of panels a piece. Micro inverters are what these smaller systems are using and they only feed power when they sense power from the grid. When the power grid goes down they don't work.
Yeah, these are designed to just plug straight into a wall outlet. These systems tend to be pretty small (just a couple panels) so exceeding the current on a 15 Amp breaker would be really unlikely. An in Utah's case it looks like they're going to be limited to 1200 Watt installations which is about 12 Amps, so well below exceeding the breaker.
From my comment below:
I think you kind of missed the scenario I was trying to describe with " 15a breaker > outlet with solar > 30a load"
Let's say the load is more like 20a. That would still normally trip the 15a breaker. If you add 1200 watts of solar in between the breaker and the load then you could potentially feed that 20a load without tripping that breaker.
I was reading up a bit on this the other day - from what I could see, the 800W limit in Germany (where these systems are apparently most popular) is set at a level where it's basically just not considered a realistic risk to the wiring. It can't push a circuit much more than 20% over its expected load (~3.5A extra), so even a worst-case failure won't start a fire; set that against the advantages of allowing it, and the rarity of a worst-case failure in the first place, and I think it makes sense even if it does marginally increase the odds of a Swiss cheese failure.
But that's 0.8kW on a system designed for 230V 16A sockets, so they're already rated for a 3.7kW load. Adding 1.2kW to a system designed around 1.8kW outlets definitely doesn't seem as straightforward... The paper I linked (which I admittedly only skimmed) does discuss Utah's options a little bit, but it looks like it was written before the regulations were finalised, so I'm not sure what they actually went with in the end.
Correct. This has some data showing just how hilariously successful they’ve been in pushing renewables forward here. The bar chart further below says
… and is already demonstrating crazy growth while not even showing data for the current year yet.
Solar power, and in particular modern photovoltaics, has become way, way too cheap to ignore, with supply outpacing demand even still; together with all the awesome research in this space it’s really looking exciting!
Oh! I see what you're saying now, my mistake. Yeah I suppose you could exceed the rated load on a circuit if it had generation on it. Not sure how to fix that, that's an interesting problem.
Reading what @Greg said about germany limiting it to 800w on 230v systems so that it would operate in that 20% safety margin got me thinking. Maybe put a smaller breaker on that circuit.
So put a 10a breaker instead of 15a and cap the solar output to 800-1000w so you're just hitting that same 20% safety margin and you just deal with the fact that you can't run a space heater on that circuit. I can't see this solution actually happening though as it feels like kind of a janky solution and it's sort of missing the point of balcony solar being easy.
I wonder how they are going to handle backfeeding safety with all these little panels. I didn't see anything about it in the article.
Microinverters. They sense power from the grid and then send power back. Power drops out, micro inverters shut off.
The downside is no solar power when the power goes out.
That makes sense, but it also means the safety of the grid relies on the design and correct function of the individual devices. For something where people will be buying the cheapest knock off devices from amazon, I find it concerning, but I hope my concern is overblown. Hopefully the output is small enough that it doesn't create too much risk for people working on the lines in an outage.
Comment box
The UL 1741 standard apparently handles this but I don't know how stringently it would be enforced on the manufacturer level, as you say. It's voluntary I think.
There is negligible risk to the grid though. Household electricity demand is a small part of total demand. The number of units this issue could apply to is a subset of the number of people who would decide to get one, which is a subset of apartment-dwellers, which is maybe 10% of the USA population, which is a subset of total demand. Even if 10% of auto-disconnect functions failed simultaneously (implausible), at the same time as a localized grid blackout (also implausible), the output would be too small to have any meaningful effect. Even in a city, the grid is big ---- the smallest grid in the USA is Texas which is an entire state.
There is a risk to electrical workers because electricity is inherently dangerous. I'm not an electrician but I believe it is standard practice to physically isolate a line before doing maintenance on it. The worry would be that the electrician believes a line is dead but the device is backfeeding because it's broken. If they're operating on a single circuit, that could shock someone, but it's not fatal. Whereas if they failed to follow circuit isolating procedures, the live energy of a whole house could totally kill them. So presumably any electrician is wearing some PPE to begin with. With precautions I speculate the risk is minimal.
Obviously regulation to make sure devices are following the standards would be ideal. But that's for the state government to decide.
If it works in other countries I don't see why it wouldn't work here.
You're correct about the isolation, but they typically isolate on the supply side, because in a centralized generation model, if you cut off the source, everything below it is off by definition. It's not quite that simple because most distribution grids are fed by more than one transmission source, but the power company has a well understood procedure for ensuring a line is dead before working on it.
A lethal amount of electricity can be quite small (in the milliamp range) if the current path passes through the heart. So I think the risk is real for someone working a downed line near an apartment or house that has a faulty unit that's back feeding the main. The worst case is: the line appears to be dead, the lineman tested it and confirmed it was dead, then sometime later one of these panels kicked on and they get zapped.
But as you say, if this is already common elsewhere (Europe), there are stricter regulations around the manufacture of goods that might not translate to a less regulated US market.
The saving grace for a cheap panel is that if it does not have a high quality sine wave source (like a generator, which is designed to work in the absence of other power) would have. This helps because if the frequency collapses or is very low, you're not going to transfer power back through the pole transformer (transformers need AC voltage to work).
I think a big thing with plug in solar is that the generation from these (at least in the context of apartment sized living units) will be lower than the residence's total base load, so for most of the people who would want this, back feeding is pretty unlikely. And in Utah's case, it looks like the law change limits these to pretty small systems.
Not to say that back feeding to the grid would be impossible, but not as likely as with a larger home solar installation.
That said, I think these inverters are usually designed to follow the frequency of the grid and to stop outputting power as soon as there's no power coming in from the grid. So I'd imagine as a regulatory point, states would be interested in only allowing systems that automatically cut power as soon as grid power drops for safety.
I'm very, very interested in this tech.
I've got one small 200w panel that can charge up a pair of 350w/h batteries in about five hours. Doesn't even have to be strong/direct sunlight either, that panel makes juice on low light just fine. Handy for when power goes out as those batteries can run a fridge, the water pump, the furnace, and the pellet stove for several hours at a time. They can also recharge lanterns, flash lights, phones, and run lights or fans or other smallish appliances. I just picked these up because they were on clearance and I wanted to play with the tech. It's kinda cool carrying around electricity like water.
The two batteries are light and small enough to fit right in a backpack, which is great for running small electrical power tools like a leaf blower or weed eater. I'd love to ditch the gasoline power tools for an electric set, they last longer and are lighter overall, plus I don't have to worry about making sure all my batteries are compatible with the power tools. Most of the companies do vendor lock in - no thanks, this way it's universal and I don't get fleeced buying low quality power tool batteries. The tools cost far less if they are just simple electric outlets with no battery tech built in. The money is better spent on a big battery pack and some extension cords.
I'd need a 1200w portable battery to run the chainsaw (for one hour's operation time total). At that size the word 'portable' is debatable, however with lithium-sulphur batteries coming, a ten pound battery that can manage 3000w could cost under three hundred bucks in a couple of years time. That would really put the nail in the coffin for gas power tools (which are a far greater polluter than automobiles - gas power tools have no catalytic converters).
I have a big roof (about 1800 sq ft) that's in direct sunlight from about an hour after sunrise all the way through sunset. If I covered that thing in solar panels, even on an overcast winter day it would still get enough light to produce a couple thousand watts of charging power. All that's missing is a big base load battery like this 50kw model or perhaps something even more aggressive.
I've got a great generator that runs on gas, natural gas, or propane. Quiet as a person talking plus puts out clean inverted power too, won't fry any electronics. The circuit panel has a pair of 50A breakers (from 1962, still working) and is wired to be fed from a proper 4-prong generator hookup in the garage. All I have to do is flip the master switch to keep it disconnected from the grid so I don't blow some poor electrician off of a pole further up the road. Then it can power all the outlets, no fussing with extension cords.
Put all this together and I'd have a steady flow of power coming into the big battery from solar all the time, and the ability to switch over to generator power to run the entire house (even big ticket items like the dryer or oven or water heater simultaneously). Anything extra the generator is making (it idles around 3000w) gets dumped back into the battery. If grid power goes down, I can coast for ages on the solar and solar storage. The water heater (115gal westinghouse) keeps the water hot almost an entire week so I wouldn't even need the generator to shower.
I prefer smaller portable propane tanks but with this system I could go in for a larger one. They aren't that expensive. The propane and natural gas are super cheap fuel sources in the USA - we make so much of it as fracking byproducts that they regularly burn it off into the air in their rush to get oil. We've had to pass laws to get companies to ban flaring the wells and stop them wasting natural gas. :p
I also need to invest in heat pumps. They don't do so well in winter under sub-freezing temperatures, but they are killer air conditioner replacements at a fraction of the power consumed.
That setup means I don't have to care about the power grid, since I've got everything I need to roll my own. Our electric prices have tripled over the last five years (>$500/mo) so I am not a fan of the power company. I am going to invest in building out something like this just to get them off my back. If they want to change state laws to make that easier then great, I'm all for it.
Ditch the idea of a unified power grid completely, focus on micro-grids instead. It's not exactly solar punk living yet but it's a step in the right direction for sure. It'll do until I can get a fridge-sized small modular nuclear reactor to step in for the generator. :)