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Question for those in the know... See lots of press about balcony solar in Germany, and California recently introduced a bill to allow it (I'm guessing other st

Question for those in the know... See lots of press about balcony solar in Germany, and California recently introduced a bill to allow it (I'm guessing other states already allow it; not sure if the CA bill has a chance of becoming law). But how far are we from a more plug and play home solar system that becomes a primary energy source as opposed to a limited secondary source? And what are the issues with it actually becoming a reality? Is it primarily regulatory where government, utilities, installers would fight it tooth and nail to protect revenue and/or the grid? Is it a legit safety issue? I have to imagine safety could be easily addressed in terms of the power management between grid and solar (obviously these balcony units are relatively safe, but tiny in comparison). Installation perhaps has more safety issues (e.g., installing panels on a roof), but I just wonder if it's reasonable to think that a more robust plug and play option will become available or is even already available in certain places. And I feel the need to say this, but this is the type of question I'd immediately turn to an LLM to answer, and I probably will ultimately, but I "still" like getting peoples' on-the-ground experience/expertise.

awjlogan 4mo ago
Regulation aside, a significant issue is physical area. Most people won’t have access to enough area in the right direction to make it a primary source.
trial3 4mo ago
i think it’s kind of the opposite: balcony solar is good for power companies in the same way that them asking you to turn off your lights is good for power companies: if each customer is using less overall power they can serve more customers with existing infra. that obviously depends on time of use and the sun etc, but balcony solar in the USA can’t come fast enough. my electricity in NYC is almost $.40/kWh, a limited secondary source is still huge it makes a lot of sense to me as someone who has casually researched as a way to make the load of an A/C vanish from the perspective of my utility, but i can’t see regulations catching up nationwide soon. any real microinverters can detect the grid being down and shut off to prevent zapping people working on power lines, but the complexities of split-phase power (you can consume on one leg but backfeed on the other leg rather than consume what you generate, which is bad for billing etc) and risks of intra-circuit overload will all freak out americans. we put outlets absolutely everywhere because of how scared we are of extension cords, there’s an education and “am i going to start an electrical file” consumer sentiment obstacle to widespread adoption in the US
- tencentshill 4mo ago
  Have you seen this? Free battery in NYC if you charge it with off-peak power https://everyelectric.com/ https://everyelectric.com/
- arbitrary_name 4mo ago
  i think that is an overly simplistic axiom: the utilities must cover a fixed asset base (poles and wires and transformers), pretty much regardless of how much or whether a household consumes from the grid. the less the utility recoups via billing for energy usage, the bigger the deficit to cover their fixed network costs. they are frequently interested in having you consume energy, to help defray those costs, especially where the marginal cost of the energy is very low. the more users who disconnect, the more the fixed costs must be recouped from a shrinking customer base, triggering more incentive to leave the network. this is called the death spiral. In addition, things like balcony solar don't save them cost: it introduces complexity because they need to safely manage that load, they need to be able to predict and measure it; in my experience working with utilities and network operators for many years, they flat out don't want these distributed generation sources unless they have a lot of say in how they are added to the grid, and how users can be charged for the privilege of generating their own power. that is often a very significant barrier to regulatory change.
  - trial3 4mo ago
    that’s true, i was considering only the perspective of the major city i live in rather than networks with lower ratepayer densities where the economics are probably totally different i do think “fully consumed or gated to never backfeed balcony solar at scale” is all i’m referring to, which i naively hope is a smaller regulatory change than backfeeding
    - 0cf8612b2e1e 4mo ago
      Everything I have seen about balcony solar requires it to be grid dependent and cannot backfeed.
    - 4mo ago
Filligree 4mo ago
There’s a legit grid stability issue for solar in general, balcony or no. Usage varies second by second, so the grid relies on physical inertia in the form of rotating turbines. Panels have no inertia; therefore, the more you have the less stable the grid gets. That is however something which can be fixed by grid-scale batteries. Or home systems, for that matter, if they have batteries and some equivalent of Victron’s PowerAssist. (Which limits the rate at which power draw can change. Very useful when you use a house-sized generator; it amounts to synthetic inertia. I have a 7kW generator, but a 7kW step load would stall it.)
- mrspuratic 4mo ago
  Plus /actual/ flywheels to compensate for non-synchronous generation: https://www.esbinternational.ie/case-studies/details/moneypoint-synchronous-condenser-flywheel https://www.esbinternational.ie/case-studies/details/moneypo...
  - marcosdumay 4mo ago
    You would need supercapacitors, but you can make an inverter emulate inertia almost as well as flywheels, and more than well enough to not make a difference once you push the energy into a few kilometers of non-zero impedance grid.
    - daedrdev 4mo ago
      supercapacitors are quite difficult because they can explode
      - marcosdumay 4mo ago
        I have some news about flywheels...
- harmmonica 4mo ago
  Ah, this is why I come here. I had no idea that was the case. I feel like there was a story going around recently about how hard it is to restart some power generator if it gets knocked offline. Maybe it was about Hoover Dam now that I think about it (i.e., how bad it would be if the Colorado gets too low).
davidw 4mo ago
Utah passed a balcony solar bill; I think they're the only ones so far. Oregon tried in the short session last year, but it got shut down by fire marshall type people, sadly.
- harmmonica 4mo ago
  Interesting on Utah. Re Oregon, was the fire Marshall acting in good faith in that scenario? Recently reading about fire-truck size in the US I start wondering what the motivation is for some views about things around fire safety (amongst a million other things). Maybe good faith is too cynical. Maybe just hard-to-change attitudes.
  - davidw 4mo ago
    Hah - I was going to mention all the other types of things the fire people seem to be blocking, but decided to stay focused. But yeah, it seemed like 'aversion to change'. "Firefighters might trip over solar panels on balconies" or something kind of far-fetched sounding.
    - harmmonica 4mo ago
      This is funny. You might notice that I write insanely-long comments because these types of things pop into my head every time on HN (better get ahead of it because people will pick apart my quick comment if I don't cover as many bases as possible in the original comment!). Your method is better! I have to learn how to be more "focused" and let folks just do their thing and then reply succinctly like you did here.
      - davidw 4mo ago
        Good plan.
  - daedrdev 4mo ago
    Firefighters are infamous for creating elevator regulations that require being able to rotate a stretcher, which lead to less elevators duet to the immense costs, which is both completely unnecessary and defeats the entire purpose of the regulations for safety since now they have to drag injured people down stairs
mbgerring 4mo ago
It’s primarily a regulatory issue, and more states in the US will approve it over the coming years.
- harmmonica 4mo ago
  I don't see anyone replying to you here, and I don't know what your background is in this, but I think and hope you're spot on here. The more I've read replies in this thread the more I think this is mostly regulatory and maybe slightly a hardware issue (hardware issue is that there needs to be some kind of plug on an electrical panel that would remove the risks of having to pull the face off the panel, install a new breaker and connect the inverter).
  - mbgerring 4mo ago
    I've worked in clean energy for about a decade, building analytics software for DER providers (solar, batteries) and EV companies, and I build large-scale portable battery and solar systems as a hobby. I keep up with the industry and the regulatory environment closely via podcasts, newsletters, and conferences.
colechristensen 4mo ago
>how far are we from a more plug and play home solar system that becomes a primary energy source as opposed to a limited secondary source? We don't need a more plug and play system. A zero agreement interconnection for whatever UL certified 300W-ish scale is fine and should be widely deployed. There needing to be interconnection agreements with your utility and an inspection is not a blocker that needs to be removed. Most places require a licensed electrician for complex work, having the electrician fill out a form and having a utility inspection is how things should be.
- harmmonica 4mo ago
  Apologies if my reply here is not understanding you, but this is counter to my experience. Plenty of people still want to handle their own energy production even if they have grid access. I've built off-grid houses. Most of the utility production is already renewable. Many people still choose to live off grid even though that's the case. It would be epic if there was a plug and play, house-scale option because the cost of installation today is... epic (so epic in fact that the overall cost of install has actually gone up even though material costs have come down). Admittedly off-grid installs are a tiny fraction of places on the planet, but it's the trigger that led me to ask about this. Perhaps you're just responding because I brought up grid tie (fair!), but I'm wondering why not aspire to remove the blocker, which would mean de-risking the installation so that laypeople could do it without having to get an electrician involved (which is what's so amazing about balcony).
  - colechristensen 4mo ago
    If you want grid tie-in, a certified professional needs to be in the loop to verify all of the rules are being followed because incorrect setups are dangerous to other people. Also insurance probably doesn't want to insure your home if someone with questionable knowledge is setting up wiring and energy production. Outside of cities, outside of grid tie, setting up your own micro-grid often can be done without any external intervention. You have to know things to do it though, I don't think it is a desirable state of things for just blind plug and play.
locallost 4mo ago
It can't be more or much more than the 800W as currently done in Germany because it would not be safe with the way electricity is delivered to a home. The reason is: when you pull electricity from the grid, the fuse would blow if you tried to pull too much current (e.g. you connect four hair dryers on the same outlet). It blows to prevent the wiring in your home from overheating and catching on fire. With balcony solar, you plug it in your home outlet which is already behind the fuse, which means the fuse cannot react and cut off power if you try to feed in more than the capacity allows. You could be maxing out on the current you are pulling from the grid, and then on top of that you would be adding your balcony solar. Why it's allowed at all in Germany and other places is because the fuse will blow above 10A and the wiring in the house is 16A, so there was always a buffer or overcapacity in the wiring, presumably just in case. So they allowed 800W of balcony solar which is roughly 3.5A and still there is some wiggle room left. Also why pull from the grid at all: your appliances actually just use the electricity from the grid. In Germany and I guess most of Europe they run a three phase system, so your balcony solar might not be in the same physical circuit as your appliances in use. With balcony solar your meter just offsets your consumption with whatever you are feeding it at the moment. From the grid standpoint if you are running something using 800W and feeding in 800W, it's 0. Of course it can work without this too, but this defeats the purpose of balcony solar, which is plug it in and it works simplicity.
- harmmonica 4mo ago
  This is very interesting and helpful info! I guess my fantasy is that a standard electrical panel would eventually have a literal plug on it where you could plug a larger system in, just as you would an outlet in the balcony situation, and then it would I think be, using your word, in "front" of the "fuse" (using quotes because I'm not sure I have the behind/in front of language correct, and when you use fuse here in the states it would be a breaker, I guess, not an actual fuse). This solution would of course have to mitigate things like fire risk, or blowing up the house or grid itself. I'm just hopeful it's coming because I think the install rate would go through the, pardon me, roof.
  - Kaliboy 4mo ago
driverdan 4mo ago
A standard rooftop solar install with micro inverters is already pretty much plug and play. Wiring it up is the easy part. Even a more complex system with large centralized inverters and battery backup can be about as plug and play as a desktop computer if you use an all-in-one inverter/charger/controller. The challenge is scale. You can't take 10kW of solar and plug it into an outlet. It requires more hardware and wiring than that.
- DANmode 4mo ago
  but you CAN just plug all of your stuff into the inverter.

awjlogan 4mo ago

Regulation aside, a significant issue is physical area. Most people won’t have access to enough area in the right direction to make it a primary source.

trial3 4mo ago

i think it’s kind of the opposite: balcony solar is good for power companies in the same way that them asking you to turn off your lights is good for power companies: if each customer is using less overall power they can serve more customers with existing infra. that obviously depends on time of use and the sun etc, but balcony solar in the USA can’t come fast enough. my electricity in NYC is almost $.40/kWh, a limited secondary source is still huge it makes a lot of sense to me as someone who has casually researched as a way to make the load of an A/C vanish from the perspective of my utility, but i can’t see regulations catching up nationwide soon. any real microinverters can detect the grid being down and shut off to prevent zapping people working on power lines, but the complexities of split-phase power (you can consume on one leg but backfeed on the other leg rather than consume what you generate, which is bad for billing etc) and risks of intra-circuit overload will all freak out americans. we put outlets absolutely everywhere because of how scared we are of extension cords, there’s an education and “am i going to start an electrical file” consumer sentiment obstacle to widespread adoption in the US

tencentshill 4mo ago
Have you seen this? Free battery in NYC if you charge it with off-peak power https://everyelectric.com/ https://everyelectric.com/
arbitrary_name 4mo ago
i think that is an overly simplistic axiom: the utilities must cover a fixed asset base (poles and wires and transformers), pretty much regardless of how much or whether a household consumes from the grid. the less the utility recoups via billing for energy usage, the bigger the deficit to cover their fixed network costs. they are frequently interested in having you consume energy, to help defray those costs, especially where the marginal cost of the energy is very low. the more users who disconnect, the more the fixed costs must be recouped from a shrinking customer base, triggering more incentive to leave the network. this is called the death spiral. In addition, things like balcony solar don't save them cost: it introduces complexity because they need to safely manage that load, they need to be able to predict and measure it; in my experience working with utilities and network operators for many years, they flat out don't want these distributed generation sources unless they have a lot of say in how they are added to the grid, and how users can be charged for the privilege of generating their own power. that is often a very significant barrier to regulatory change.
- trial3 4mo ago
  that’s true, i was considering only the perspective of the major city i live in rather than networks with lower ratepayer densities where the economics are probably totally different i do think “fully consumed or gated to never backfeed balcony solar at scale” is all i’m referring to, which i naively hope is a smaller regulatory change than backfeeding
  - 0cf8612b2e1e 4mo ago
    Everything I have seen about balcony solar requires it to be grid dependent and cannot backfeed.
  - 4mo ago

Filligree 4mo ago

There’s a legit grid stability issue for solar in general, balcony or no. Usage varies second by second, so the grid relies on physical inertia in the form of rotating turbines. Panels have no inertia; therefore, the more you have the less stable the grid gets. That is however something which can be fixed by grid-scale batteries. Or home systems, for that matter, if they have batteries and some equivalent of Victron’s PowerAssist. (Which limits the rate at which power draw can change. Very useful when you use a house-sized generator; it amounts to synthetic inertia. I have a 7kW generator, but a 7kW step load would stall it.)

mrspuratic 4mo ago
Plus /actual/ flywheels to compensate for non-synchronous generation: https://www.esbinternational.ie/case-studies/details/moneypoint-synchronous-condenser-flywheel https://www.esbinternational.ie/case-studies/details/moneypo...
- marcosdumay 4mo ago
  You would need supercapacitors, but you can make an inverter emulate inertia almost as well as flywheels, and more than well enough to not make a difference once you push the energy into a few kilometers of non-zero impedance grid.
  - daedrdev 4mo ago
    supercapacitors are quite difficult because they can explode
    - marcosdumay 4mo ago
      I have some news about flywheels...
harmmonica 4mo ago
Ah, this is why I come here. I had no idea that was the case. I feel like there was a story going around recently about how hard it is to restart some power generator if it gets knocked offline. Maybe it was about Hoover Dam now that I think about it (i.e., how bad it would be if the Colorado gets too low).

davidw 4mo ago

Utah passed a balcony solar bill; I think they're the only ones so far. Oregon tried in the short session last year, but it got shut down by fire marshall type people, sadly.

harmmonica 4mo ago
Interesting on Utah. Re Oregon, was the fire Marshall acting in good faith in that scenario? Recently reading about fire-truck size in the US I start wondering what the motivation is for some views about things around fire safety (amongst a million other things). Maybe good faith is too cynical. Maybe just hard-to-change attitudes.
- davidw 4mo ago
  Hah - I was going to mention all the other types of things the fire people seem to be blocking, but decided to stay focused. But yeah, it seemed like 'aversion to change'. "Firefighters might trip over solar panels on balconies" or something kind of far-fetched sounding.
  - harmmonica 4mo ago
    This is funny. You might notice that I write insanely-long comments because these types of things pop into my head every time on HN (better get ahead of it because people will pick apart my quick comment if I don't cover as many bases as possible in the original comment!). Your method is better! I have to learn how to be more "focused" and let folks just do their thing and then reply succinctly like you did here.
    - davidw 4mo ago
      Good plan.
- daedrdev 4mo ago
  Firefighters are infamous for creating elevator regulations that require being able to rotate a stretcher, which lead to less elevators duet to the immense costs, which is both completely unnecessary and defeats the entire purpose of the regulations for safety since now they have to drag injured people down stairs

mbgerring 4mo ago

It’s primarily a regulatory issue, and more states in the US will approve it over the coming years.

harmmonica 4mo ago
I don't see anyone replying to you here, and I don't know what your background is in this, but I think and hope you're spot on here. The more I've read replies in this thread the more I think this is mostly regulatory and maybe slightly a hardware issue (hardware issue is that there needs to be some kind of plug on an electrical panel that would remove the risks of having to pull the face off the panel, install a new breaker and connect the inverter).
- mbgerring 4mo ago
  I've worked in clean energy for about a decade, building analytics software for DER providers (solar, batteries) and EV companies, and I build large-scale portable battery and solar systems as a hobby. I keep up with the industry and the regulatory environment closely via podcasts, newsletters, and conferences.

colechristensen 4mo ago

>how far are we from a more plug and play home solar system that becomes a primary energy source as opposed to a limited secondary source? We don't need a more plug and play system. A zero agreement interconnection for whatever UL certified 300W-ish scale is fine and should be widely deployed. There needing to be interconnection agreements with your utility and an inspection is not a blocker that needs to be removed. Most places require a licensed electrician for complex work, having the electrician fill out a form and having a utility inspection is how things should be.

harmmonica 4mo ago
Apologies if my reply here is not understanding you, but this is counter to my experience. Plenty of people still want to handle their own energy production even if they have grid access. I've built off-grid houses. Most of the utility production is already renewable. Many people still choose to live off grid even though that's the case. It would be epic if there was a plug and play, house-scale option because the cost of installation today is... epic (so epic in fact that the overall cost of install has actually gone up even though material costs have come down). Admittedly off-grid installs are a tiny fraction of places on the planet, but it's the trigger that led me to ask about this. Perhaps you're just responding because I brought up grid tie (fair!), but I'm wondering why not aspire to remove the blocker, which would mean de-risking the installation so that laypeople could do it without having to get an electrician involved (which is what's so amazing about balcony).
- colechristensen 4mo ago
  If you want grid tie-in, a certified professional needs to be in the loop to verify all of the rules are being followed because incorrect setups are dangerous to other people. Also insurance probably doesn't want to insure your home if someone with questionable knowledge is setting up wiring and energy production. Outside of cities, outside of grid tie, setting up your own micro-grid often can be done without any external intervention. You have to know things to do it though, I don't think it is a desirable state of things for just blind plug and play.

locallost 4mo ago

It can't be more or much more than the 800W as currently done in Germany because it would not be safe with the way electricity is delivered to a home. The reason is: when you pull electricity from the grid, the fuse would blow if you tried to pull too much current (e.g. you connect four hair dryers on the same outlet). It blows to prevent the wiring in your home from overheating and catching on fire. With balcony solar, you plug it in your home outlet which is already behind the fuse, which means the fuse cannot react and cut off power if you try to feed in more than the capacity allows. You could be maxing out on the current you are pulling from the grid, and then on top of that you would be adding your balcony solar. Why it's allowed at all in Germany and other places is because the fuse will blow above 10A and the wiring in the house is 16A, so there was always a buffer or overcapacity in the wiring, presumably just in case. So they allowed 800W of balcony solar which is roughly 3.5A and still there is some wiggle room left. Also why pull from the grid at all: your appliances actually just use the electricity from the grid. In Germany and I guess most of Europe they run a three phase system, so your balcony solar might not be in the same physical circuit as your appliances in use. With balcony solar your meter just offsets your consumption with whatever you are feeding it at the moment. From the grid standpoint if you are running something using 800W and feeding in 800W, it's 0. Of course it can work without this too, but this defeats the purpose of balcony solar, which is plug it in and it works simplicity.

harmmonica 4mo ago
This is very interesting and helpful info! I guess my fantasy is that a standard electrical panel would eventually have a literal plug on it where you could plug a larger system in, just as you would an outlet in the balcony situation, and then it would I think be, using your word, in "front" of the "fuse" (using quotes because I'm not sure I have the behind/in front of language correct, and when you use fuse here in the states it would be a breaker, I guess, not an actual fuse). This solution would of course have to mitigate things like fire risk, or blowing up the house or grid itself. I'm just hopeful it's coming because I think the install rate would go through the, pardon me, roof.
- Kaliboy 4mo ago

driverdan 4mo ago

A standard rooftop solar install with micro inverters is already pretty much plug and play. Wiring it up is the easy part. Even a more complex system with large centralized inverters and battery backup can be about as plug and play as a desktop computer if you use an all-in-one inverter/charger/controller. The challenge is scale. You can't take 10kW of solar and plug it into an outlet. It requires more hardware and wiring than that.

DANmode 4mo ago
but you CAN just plug all of your stuff into the inverter.