Balcony solar is taking off
183 comments
·February 7, 2025wongarsu
ttt3ts
Fewer outages vs US source? I work in the power industry in the US and I am sure this is regionally true but highly doubt it as a blanket statement.
wklauss
U.S. electricity customers averaged five and one-half hours of power interruptions in 2022
Source: https://www.eia.gov/todayinenergy/detail.php?id=61303
In 2023, German households experienced an average of 13.7 minutes of power outages.
Source: https://www.heise.de/en/news/Power-supply-13-7-minutes-of-po...
Not sure if the metrics are 100% comparable (they seem to be?) but points to a huge difference in reliability.
jwr
As an anectdotal data point, I live in Poland (Warsaw) and I can't remember the last time I had a power interruption at my home. I don't use UPSs at all, and my NAS gets years of uptime, unless I decide to reboot it.
This gets much worse if you live in the countryside, for obvious reasons, and I would guess that the German average is mostly driven by countryside, not big cities.
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dylan604
How many hurricanes did Germany have in 2023? How many tornadoes did Germany have in 2023?
Let's not think that weather has nothing to do with any of this. That would just be beyond insulting
tcoff91
Any time the Santa Ana winds pick up in so cal they turn the power off to prevent fires now so yeah the US power infrastructure is shit compared to Germany. Over there it’s all underground because when they rebuilt after ww2 they realized it’s dumb to have it be so easy to blow up your power grid with bombs.
PaulDavisThe1st
Putting it underground doesn't stop it being blown up with bombs.
babypuncher
This is sort of my problem with pushing at-home solar as a primary means to de-carbonize our electricity production. We still need grid access, but with more people not getting their electricity from the grid, the cost to maintain it gets shifted to those who still use it as their primary source of energy. And, well, it's not the poor who are installing kilowatts worth of solar capacity and battery storage on their property.
pkulak
We _need_ grid access, for now. Batteries are getting so crazy cheap. LFP is hitting the market en masse, and right behind that is sodium ion to halve the price again.
And, at least where I am, grid _access_ isn't really the biggest cost, capacity is. My power company would love it if I hooked some batteries up to solar and used that during peak hours so they don't have to upgrade every transmission line between me and a bunch of coal in Idaho. In fact, I know this because they pay me to do *exactly that with time-of-use metering.
* I don't actually have any solar, but I do have an electric water heater and an electric car, which are both huge batteries, and easy to time shift the charging of.
hedora
If you get two EVs equivalent to average size American cars, that’s over 200 kwh of storage.
That’s equivalent to roughly 15 tesla powerwalls, and newer models can charge your (tiny) house battery as needed during power outages.
Having said that, community net metering makes way more sense in urban areas than per-building solar. The idea is that, by law, you can buy a small fraction of a neighborhood wide solar or wind farm (e.g. on a commercial parking lot, or a few blocks away, etc), and the power company offsets your power consumption bill with the electricity your fraction of the solar installation produced.
Moto7451
This is only the case in a few markets that still do 1:1 net metering. I still get charged a grid connection fee (which you’re charged even if you use zero electricity) and when I sell power back to the grid I only am credited the production value and not the full kWh rate. As a result anything I net back I still pay the cost of the transmission infrastructure.
anotherhue
I expect that could be mostly solved by changing the billing metric, pay for the ampacity of the hookup not the energy.
gorbypark
I’ve been looking into doing this on my balcony in Spain. They sell “plug in” solar kits, but I’ve yet to determine if it’s actually legal here. I have a south facing balcony that’s about 1mx3m, so should be able to get about 400-600 watts of panels on the railing.
I actually came across this article in my research and it’s the only thing I’ve found saying it’s legal if it’s under 800w. From what I’m gather it’s just a few solar panels and an inverter that feeds electricity into a socket, more or less. My concern is what happens when there’s a power outage? I’d then be feeding power into a system that’s “denergized”. I know with real solar setups there’s an automatic cutoff when that happens to protect people working on the lines…all the kits i see here mention nothing about a cutoff system.
Tade0
Regarding legality: According to Commission Regulation EU 2016/631 systems under 800W don't qualify as any of the regulated types of power generating facilities, so any law that would limit their installation must be local.
In practice you need to have a two-way meter installed by the power company and you're good to go.
jillesvangurp
I live in Berlin, I have some friends that bought some panels just because they could. I'm considering myself even though I don't get a lot of sunlight on my balcony. I only pay about 60 euro per month. But these kits only cost a few hundred euros. So why not? If it saves me 10 euro per month or so, it would earn itself back in 3-4 years under ideal circumstances. It's not a huge saving obviously.
> My concern is what happens when there’s a power outage? I’d then be feeding power into a system that’s “denergized”.
This is Germany, they would have studied that topic thoroughly. In short, the certified inverter that you must use for this would indeed shut down in case of a power loss. This is usually called "anti-islanding protection" and not an optional feature for this.
stadeschuldt
In Berlin, you could get it for free through the SolarPLUS[1] subsidy program. My setup (2 panels, inverter and mounts) cost less than 500€ and was fully subsidized.
carlosjobim
Ask yourself why you are interested in an investment that has only meager returns if everything works out well? Is it worth your time thinking about +/- €10 per month? If that's the case, you could probably achieve it just by using a little less electricity.
tbossanova
Or do both?
Jalad
> But these kits only cost a few hundred euros. So why not? If it saves me 10 euro per month or so, it would earn itself back in 3-4 years under ideal circumstances
I'm not saying this is an unreasonable position, but the net present value of an investment that pays 10 euros a month for 4 years is also a couple of hundred euros. So in the end it might be a wash (or might not beat out investing in higher yield projects)
https://www.calculatorsoup.com/calculators/financial/present...
cameldrv
My understanding is that the inverter you get in the kit that you plug into the wall will shut itself off if the power goes out, the same as most larger non off-grid solar systems.
maxerickson
There's a link to a pdf manual for what appears to be a fairly common one here: https://github.com/tbnobody/OpenDTU/discussions/855
The inverter is designed to stop feeding power if the grid drops off.
raphaelj
I've an EcoFlow plug & play inverter, and it automatically shuts off if the grid comes down. That's a requirement for all these devices.
60Vhipx7b4JL
Those are grid tie inverters, they cannot/will not output if no grid is present.
macropin
I'd be interested to find out what sort of anti-islanding techniques they employ. Most inverters are relatively slow to detect grid failure, and if you pull the plug out quickly you might get a shock.
walrus01
At additional cost, one could install a fully manual physical transfer switch which disconnects the PV panels entirely from the gridtie inverter and your apartment's breaker panel, and connects it instead to a charge controller and battery system. Such as one of the nominal 50Ah or 100Ah "48V" Chinese LiFePo4 batteries which come in 2U to 4U rackmount size.
It would be an either/or configuration if done as cheaply as possible such as for a balcony storage system, not capable of both usages simultaneously.
You would then need to have a separate distribution of power from the battery system to your loads. Such as something like a 1000W true sine wave inverter to power essentials like laptop, phone chargers, basic lighting etc during a full power outage.
maxerickson
The small inverters used in these balcony setups aren't setup to provide power without a grid reference.
metalman
The way power is shunted into the grid is very simple.The inverter you have senses the line voltage, and by keeping its voltage a tiny bit higher, "knows" that the power will flow out. nothing to sense and push against and it will idle likely doing an on and off test routine till if finds something to push against. Vs an off grid inverter that is stand alone, and self referential. There are hybrid off/on grid inverters, but they will quickly stop sending current, without a reference voltage, and drop back to battery/solar. As to legalities....,if there is no regulation adressing it, its legal, beurocracys hate that, but there it is. Its not like they wouldn't pin an (unlikely) accident on you either way, so..... and with no batteries, there is more risk in dropping the panel or another mechanical failure than anything electrical
jakewins
> As to legalities....,if there is no regulation adressing it, its legal, beurocracys hate that, but there it is.
This is not law works. Either way there absolutely is regulation in minute detail about backfeeding power into your home, in any jurisdiction in EU or USA I’m aware of
standeven
I really wish we could remove the 100% tariffs on solar panels and EVs from China and let the free market do its thing. It feels like lobbying and red tape are the biggest things holding back the energy transition at this point.
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hedora
We can’t do that. Those are subsidized. That’s completely unfair, unlike in the US, where you get a tax break for buying them.
/s
exabrial
In the USA, given that the vast majority of apartments don't have to pay energy bills, this means they don't have an economic incentive to upgrade appliances, provide adequate insulation during construction, or maintain air seals. My old apartment, constructed in 2002, had dual pane glass, but it had LONG lost its air seals (very cheap 15 year warranty windows). There is zero chance the apartment was going to upgrade the 4000 windows in their complex.
This loophole is a major source of energy waste, and there's not a great way around it unless apartments are forced to bundle bulk energy costs with rent, which has other undesirable side effects.
itsoktocry
>In the USA, given that the vast majority of apartments don't have to pay energy bills, this means they don't have an economic incentive to upgrade appliances, provide adequate insulation during construction, or maintain air seals.
I don't understand this argument.
Someone is paying the bill (the owner), and they are also paying for maintaining air seals and upgrading appliances (you don't bring your own). Why don't you think there are economic incentives?
In fact, I'd argue there are greater incentives to do this for the building owner: greater scale and more efficiencies.
tass
I think OP might be saying apartment owners don’t pay the bills (because the apartment tenants do).
Then the argument makes sense.
lizknope
I've rented 3 different apartments in the US. I always had to pay electricity myself. The water was included as part of the rent.
digdugdirk
That's what the previous comment is saying - the tenant is responsible for the electricity cost, but has no ability to make capital improvements/investments to increase efficiency. Meanwhile, the apartment owner has no incentive to make those same investments, because they aren't on the hook for the monthly energy costs. It's a mismatched set of incentives that results in cheaper, low efficiency apartment buildings and higher energy usage across the country.
panick21_
In theory people should consider electricity cost when selecting where they live. Maybe there is an issue with getting that information. But I think this is the same with all renting, not just apartments.
joshstrange
Just a datapoint, I had an apartment (2019) that had all utilities included (water, electric, no gas in the building). I wondered many times if they would be able to detect a bitcoin mining operation or if they would notice.
pastage
We had a guy who found a direct connection to the grid and it was noticed, reading the article the setup was in the 2-5kW range. How many goes unnoticed is another issue.
dylan604
Back in the olden days of hot lights, grow houses could be detected by the large amount of electricity being used.
hk1337
Pretty sure OP meant apartment landlords/owners. I can see how you mistook it though, I had to read it a couple of times. Initially, you think individual apartments (i.e. renters) not apartments as in the owners/landlords of the apartments.
lcnPylGDnU4H9OF
"Vast majority of apartments" seems to be referring to the building/complex owner, not individual renters. In other words, you pay the energy bill but you don't have a say in which efficiency upgrades are implemented.
abdullahkhalids
In principle, there is an incentive - renters should be picking apartment buildings which are more energy efficient. So buildings should be competing on this metric. But, in practice, renters have no reasonable way of knowing which buildings are more efficient. And buildings will not volunteer this information.
You could mandate buildings get an energy efficiency assessment. But I imagine that will go the way of carbon credits contracts and such - mostly lies.
crucialfelix
Apartments in the EU and UK are required to have EPC Energy Performance Certificate.
By January 2030, all residential buildings in the EU must meet at least an E energy efficiency rating, and by January 2033, this will rise to a D rating or better. By 2040, all buildings must achieve an A or B rating.
cogman10
Energy efficiency happens when an apartment is built or remodeled. The right way to improve it is regulations mandating things like minimum insulation.
I wouldn't say that an energy efficiency assessment hurts, but it's also limited in what it can do to improve the situation. An apartment built with 0 insulation and natural gas heating just isn't going to be environmentally friendly without completely bulldozing the complex.
Transparency is good, but I think most renters really just won't care.
abdullahkhalids
Many car owners certainly care about gas mileage. It might not be the most important factor but there is some consideration for it. Similarly, renters could care if informed. But cars and apartments are very different products, and you can get somewhat reasonably cheap+accurate estimates of the efficiency of one but not the other. So the whole point is moot.
newyankee
What may be useful is clear law that makes it mandatory to share energy usage over past 3 years or so and the associated costs.
janalsncm
Mandate apartments report typical (median or mean) energy costs. No assessment necessary.
dredmorbius
You can often get average monthly billing from the utility company on request.
My experience is that apartment units tend to have low utility rates anyhow, particularly in larger buildings where only 1 or 2 of 6 surfaces (walls, floor, ceiling) will have any outside exposure.
If you're not too particular about temperature, it's often possible to "coast" based on the heating/cooling of your neighbours rather than heating or cooling your own space. Temperate climates such as California further reduce need for interior climate control, though construction is also correspondingly less well weather-proofed (insulated, wrapped, weather-stripped) than in colder, hotter, or more humid climates.
hansvm
The provider (landlord) and payer (tenant) being two distinct entities is part of the problem, but the other part is that the landlord actively hides that sort of information. If you ask how much water costs, they'll likely not answer, might throw out some fuzzy idea of it being normal, perhaps give you the rate per gallon, and definitely not tell you about the actively leaking pipe whose costs the tenants have to share or about the outdated appliances using 3x too much water. You don't learn about that till you're trapped in a lease, and the amount they're scamming you isn't usually worth the activation energy of taking legal action or moving.
BobAliceInATree
My washer/dryer had to be replaced, and I was able to convince my landlord to split the additional cost of a heat-pump dryer. (The QoL improvement is great since there's no vent in the unit, though it's unclear if my energy bills are actually lower).
But he's just a single-unit condo landlord, and I'm a pretty good tenant, so we have a good relationship. I can't imagine a multi-unit corporation doing this.
mattlondon
So what it is just entirely free electricity? Someone must be paying for it somehow otherwise every apartment would be a bitcoin mine by now.
jandrese
The tenant pays for the utilities. Because the apartment complex is not paying for they they have no incentive to install energy efficiency upgrades and will instead install only the cheapest hardware they can buy.
itronitron
Wouldn't the property owner have an incentive?
hooverd
Because they're not paying for it, the tenant is.
maxerickson
Building more would likely help somewhat. If supply and demand are matched up, supply has to compete.
Retric
It’s rarely obvious to tenants that their only exterior wall is extremely inefficient.
20-30$/month very quickly pays for a new sliding glass door, but it’s hardly going to get people to swap apartments.
maxerickson
I guess I'm not sure what your point is. Are you worried that building more and having apartment landlords competing for tenants will work out poorly?
I wouldn't really expect people to be switching apartments to save $30 a month, but I would sort of expect them to give some preference to the more comfortable apartment that bragged about their reduced energy costs when they were otherwise switching.
croisillon
> they are so popular the term Balkonkraftwerk (balcony power plant) has been coined
i woud argue that it is not how German works, word coining is not a metric of its popularity
wongarsu
It's like saying that the fact that the word "balcony power plant" exists is a sign of how popular it is in the English speaking world. Except that German compound words are seen as more legitimate because they lack the spaces and sound German.
croisillon
Thanks! You wrote it much better than I did!
_nalply
Quite the opposite. Balkonkraftwerk sounds immediately clear and convincing.
German Wikipedia has an article about it: https://de.wikipedia.org/wiki/Balkonkraftwerk
ahofmann
Nah, any German word with Kraft in it, is a strong sign of it's popularity ;-)
Balkonkraftwerk sounds powerful. Not like Aufhängesolarpaneel, or Steckersolargerät.
red369
Kraftwerk even!
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Gigachad
>With solar balconies, no such consent is required unless the facade is listed as of historic interest or there is a specific prohibition from the residents’ association or the local authority.
In Australia, there is no chance you'd get away with this since basically every strata bylaw document bans non typical balcony furnature and its a struggle to just get those fake plant wall coverings or even hanging your clothes out to dry.
nielsole
While that stance is about Spain, in Germany only a recent law change brought about by a petition has given balcony solar privileged status, making it harder for landlords to forbid them. Change is possible.
Gigachad
Apartments in Australia work seemingly different to the rest of the world where there is almost never a central landlord that owns the whole building, but every apartment has an individual owner and the rules are voted on by the owners.
Sometimes the state government steps in to make certain rules invalid such as banning pets. But an attempt to let people dry their clothes on the balcony recently failed. And I can see almost zero chance of allowing solar panels since they do have a significant aesthetic impact on the building along with safety concerns around panels getting ripped off in the wind. Most buildings already have solar on the roof but it mostly just powered the lifts and hallway lights.
_carbyau_
I spent years renting/owning apartments. Now fortunate to own a mortgage/house.
The amount of freedom open to you is ridiculous. It is like becoming a "first class" citizen - a "homeowner" that the politicians pander to. It is ridiculous.
To deal with apartment living is to deal with bureaucracy/politics/bullshit. And even when the people are lovely - like my last apartment building - the incentives don't align to make for sensible long term decisions for the whole building.
Solar panels with or without battery? Electric car charging? Bike shed? Heatpump-everything? Upgrade building insulation? Arrange the garden to be useful? These are now options available to me on the basis of money alone - no permission from others required.
It is stupid. I know that apartment living can be more efficient per capita in so many ways, better for city planning and public transport etc etc.
But fuck that. A lot has to change until apartments become desirable as anything than a temporary stayover.
decimalenough
As far as I can tell from 5 min on Google, balcony solar is straight up banned in Australia. As in, there are no approved models or installers, and you can't DIY anything electrical without invalidating your home insurance.
A shame, because I'm renting a house, and while I'm obviously not going to invest in rooftop solar, a portable balcony setup I could take with me or easily sell the next time I move would be handy.
Gigachad
You can set up a low voltage DC solar setup + battery yourself, but you aren't allowed to do anything that connects to the grid without the proper licenses/certifications.
But I'd say the reason you can't find product licensed to do it is because the amount of savings to be had with some panels hanging of the balcony is pretty minimal, the difficulty of securing them properly so they aren't ripped off in a storm is pretty high, and no owners corp would allow it just for visual reasons alone.
Australia has an absolute abundance of empty land, no trees and sun raining down on it. Makes more sense to invest in these installations and just wire it in to the grid rather than zip tieing panels to your balcony rails.
SinFulNard
One option could be to join something like this: https://haystacks.solargarden.org.au/
The big caveat is you have to sign up with their retail partner, the pricing structure is interesting - you aren't actually paid based on what is generated (or at least from memory).
macropin
AS/NZ standards prohibit these sorts of systems. Even most models of Victron inverters are not "approved" for grid use without an approved external anti-islanding device, which also vary depending on which energy distributer your are connecting to. Apparently Victron got fed up with dealing with CEC and paying the annual fees to be approved.
nikeee
It was pretty cumbersome in Germany, too. Balcony solar is now considered the same as a satellite dish, which doesn't require special permission.
jccooper
This is impractical in the US as things currently stand; most utilities have a permitting process for a grid tie (anything that backfeeds the grid) and smartmeters are capable of detecting and reporting any backfeed.
Mostly the technical aspects are not a problem (most modern meters are two-way); you'd just need a policy like the one in Germany allowing de minimis backfeed.
JKCalhoun
If you are actually tying the solar-panel into your house's "grid" couldn't you also make additional mods between your electrical-panel and the meter to prevent backfeed?
Or, maybe an inline battery that the solar panel tops off.
mattlondon
Do you just hook up and inverter and run your electricity meter "in reverse" then? Is that how this works?
milianw
initially yes but then the local power supplier will come and install a bidirectional meter
pintxo
In Germany, as long as the inverter output is capped at 800W (and solar Wp at 2kWp), no bidirectional meter is needed.
locallost
If you have an old analogue meter it will run in reverse, but this is illegal (you are reducing your metered usage of grid electricity, but the price of that includes grid transmission costs, taxes etc). The modern ones have a separate meter if you want to feed it to the grid, but it's not worth it, there are some fees for that so you'd end up with a few bucks every year.
So the way it works, you plug it in, and your appliances can use it and not the electricity from the grid. The excess you don't use gets fed in the grid, generally for free. You save basically on all the taxes, transmission costs etc, which are the majority of the price, if you use your own electricity. The more you can use, the more you will save.
mystified5016
If your home is fully solar powered and you are making more then you're using at the moment, then yes, the meter counts backwards.
Most of the time though, your production will be less than your consumption, so your meter will simply not count the watts you don't pull from the grid.
Asmod4n
They are so popular in Germany, you can sometimes even buy them in supermarkets.
walthamstow
I assume Germany has 'the middle aisle' in Lidl and Aldi like we do in the UK? Solar panels are exactly the kind of thing I would expect to find there :D
Asmod4n
yup, exactly there :)
daemonologist
I think it is simple - electricity from solar panels is cheaper than electricity from the utility companies, which have been too slow to build out solar farms of their own, and it is fashionable to boot. ("Fashionable" is not exactly the word I want; I mean that it would be less popular with your friends and neighbors to operate a coal-fired generator on your balcony.)
DamonHD
Suggested a similar thing to the energy minister in the UK ~2009, but officials nixed it:
welder
Here's a company a friend started for balcony solar in Germany:
In Germany on a south-facing balcony, producing your own electricity from solar panels is cheaper than the transmission costs of the power company. Meaning that even if the power company somehow had a too-cheap-to-meter fusion power plant, getting that electricity to you is more expensive than you making your own solar power.
Part of this is that transmission costs are higher in Germany than e.g. in the US, partially because Germany has a much more robust system with far fewer outages. How to structure these costs will likely become a bigger topic as more people produce their own electricity but still expect the grid to be there when they need it.