I'm German, and have installed a small (1.8kWp, 800W inverter) system myself. It's really pretty cool. It was really cheap (our system cost 750€ including installation material for the roof) and saves a lot of money (130€ since September). Ours will have recovered the upfront investment cost within the next 2 years. Our meter is currently turning backwards when we feed in, but will be replaced by a meter that doesn't (then, energy we feed back into the grid will be given away to the grid operator for free).
I forgot the coolest thing about this: We are currently transitioning from a demand-driven grid to a supply-driven grid. Previously, when more power was consumed, power plants upped their production by burning more coal, oil or gas. Now, the consumption needs to be upped when power is available via solar or wind, and reduced when it isn't. Balcony power plants do a very good job of educating and motivating people to do this.
Don't give energy away to the operator, they don't (want to) give you energy for free either. Get something which can soak up excess energy - a battery, an electric water heater, whatever - and run that on whatever excess energy you have. Assuming you don't invest too much money in such a project you'll end up saving a bit more money and you'll avoid being fined for pushing energy into an already overloaded network once everyone and his dog have installed solar which pushes up the voltage from nominal 230VAC to somewhere around 245-250VAC (250VAC is the usual cutoff for inverters where I live (Sweden)).
I installed 14.5 kW of PV panels on the barn roof a few years ago and hooked them up to a 10 kW hybrid inverter. Hybrid inverters can divert energy (from the PV panels or from the net) to a battery which can be used at a later stage to feed consumers in the local installation or to backfeed to the net. Since we currently have a contract which allows us to sell energy at market rates we do not have a battery yet but I don't know yet what the next contract (in 2 years) will look like. Assuming that we can no longer sell at market rates I'll install around 60-80 kWh in battery capacity to soak up excess production and dump the rest in the water heater etc. If we ever get a hybrid or electric car/tractor/whatever I'll add battery capacity so as to be able to charge those with excess energy. By that time we'll be close to ready to go off-grid which is fine by me, electricity prices here in Sweden have skyrocketed due to the demand from (mostly) Germany for excess capacity since you shut down your nuclear power plants. The more transmission capacity is built in the Baltic, the higher our prices get.
A battery isn't profitable for me atm, and I have no problem giving the electricity away.
Do you have a source that shows that shutting down nuclear power plants has in any way influenced German power import? I'd doubt that. Power is imported when it is cheaper to import it than produce it ourselves (there has not been a situation yet where Germany couldn't meet it's own demand).
BTW, on the subject of batteries being too expensive it might be an interesting experiment to see how far you'd get using a common full sine wave UPS with a number of external batteries. Charge the external batteries using the inverter, pull power out of the UPS. Expenditure would consists of a UPS - you'll find these on auction sites, often without or with expired battery packs - and a number of batteries. A reasonably-sized UPS which can deliver a kilowatt or more often uses 24/48/72 volt battery packs, i.e. 2 to 6 lead-acid batteries in series. If you have a way of getting these for a reasonable price it may be worth experimenting with if you're the experimenting type (I am).
Our inverter is built for high-voltage batteries (120V to 580V) so I'm aiming for either using expired EV batteries or - once prices go down more - LiFePO4 battery stacks. As it stands prices are still too high which - calculated over the life span of the batteries combined with compound interest on the investment - makes power from such batteries cost around the same as power taken from the 'net. Battery prices are steadily going down so this situation should change, hopefully within 3 years they'll have gone down so far as to make it a worthwhile investment.
Power is imported when it is cheaper to import it than produce it ourselves
After shutting down the remaining 6, then 3 nuclear power plants it became cheaper to import power from Sweden - which used to be blessed with relatively low electricity prices due to to the large hydro and (diminishing) nuclear generation capacity - than to generate it in Germany. While this might have been positive for Germany and for electricity producers in Sweden it is a definite negative for electricity users in Sweden who have seen their prices skyrocket. As to the direct effects of the nuclear shutdown there's quite a bit written, e.g.
For the first time in many years, Germany became a net electricity importer in 2023. The trade balance for electricity switched from 21 TWh of exports to 22 TWh of imports in the same period. Imports have risen despite sufficient plant capacity in Germany to cover domestic demand entirely. In March 2024, the country announced the shutdown of seven more coal-fired power plant units after the winter, as they are no longer needed to guarantee supply security.
This leaves aside other costs involved with the nuclear phase-out [1] and the knock-on effects of the increased energy prices as well as lower guaranteed availability which is part of the cause of German deindustrialisation. If you doubt whether this actually happening I invite you to peruse a search engine of your preference on the subject which is more effective than me linking to a number of articles from many different sources.
In india, atleast in my state, they let us add solar to our roof and let us give excess energy back to the grid. And they pay us back for the energy that is sent back to the grid
I believe that is such almost everywhere in the world. Alternatives for excess of energy tend to be much more expensive, unless there is no grid to connect to.
That's common on places where there isn't a lot of solar back-feeding the grid. When the amount gets big enough, it short-circuits the grid's cash-flow way before it becomes a nuisance electrically, and the rules change.
Places where they happens a lot run into issues since the sun doesn't always shine when people want power. People generally want to have a power bill of zero after installing these, but that cannot work out - they still need to pay for their share of the grid, plus whatever plan the grid as in place for nights. Depending on how many are doing this, it is possible to be in a point where there is more power than needed on the grid.
Live in an apartment in NYC and would love some way of turning our windows into solar panels. They only thing I've seen is a ~$100 device from a company called grouphug (no affiliation) whereby a small solar panel is stuck to a window via suction cup and can charge a phone (I believe it has a small in-built battery). Laudable but I wonder if it would return the investment.
It won't. These systems are quite large (a single solar panel is approximately 1.2m by 1.7m (4 to 6 ft ?) and even if you put it outside with direct southern exposure and no shade it takes 2-5 years to recoup the investment cost. In the US, you pay less for electricity (in most places) so it would take longer. Behind a window, generated energy will be way less.
Operating electrical power grids requires a very careful balance between production and consumption. Long term trends are regulated on the consumption side through pricing, short term jitter is regulated on the production side through switching power plants on and off.
Traditionally, a power grid only had medium and large power plants, and they are not only connected to the power grid but also a control network. Adding many small power generators poses a problem in how you communicate and coordinate with them.
800w is the maximum being produced, and not all of it will be fed into the grid. And it is unlikely that millions of households have all installed powerplants which are all oriented in the same direction and not shaded.
Germany is 84 million people. If 1% have solar and they currently average to 400 watts (half capacity from their 800 watts because of positional and shading issues) that is 33 Gigawatts. That much power if not managed will cause problems for any grid.
These things just plug into a power outlet. Requirement for Austria is a Smart Powermeter, because the old, analog ones would run in reverse if the solar panels produced more then you are currently using. They may not exceed 800W and are required to turn off if no power grid is detected, e.g. during a power outage. Apart from that, just institutional conservatism and inertia as far as I know.
Because they are potentially deadly in certain failure states. Normally system you expect system to be dead when main switch is turned off. But in this case something might be feeding in power. Same goes for over current protection. You really do not want power when you expect there to be none. Even if you should always check.
This is not really an issue. The inverters used in these cases rely on an existing power supply for synchronization with the electrical grid. If there is no power on the socket, the inverter has no means to generate a sine wave on its own and does not provide power on its cable.
This is true (as far as I know) for ALL inverters, apart from "off grid" solutions, so workers can turn off power on a street level. If that wasn't the case, there would be no way for technical staff to make sure that lines going to multiple homes (with solar) are powered off.
I can how it would not switch on if line power is gone. But what if it is on already, there are not many loads on, and the mains go down? Does it switch off? How does it know?
READ THE OTHER REPLIES FIRST. I'm going to assume you did as they are right about what this can't happen.
When you backfeed like that your neighbors will draw on your power - but they will attempt to draw more than you can provide and so your circuit breakers will trip. The only way backfeeding could be an issue is if you have a very large generator and the area islanded is only a couple neighbors such that the total power use is less than the theoretical max of your house.
That said, linemen are trained to either treat all wires as live or short them to ground. They can never be sure they are not in that rare exception case and mistakes can be deadly.
Technically probably yes, provided you had millions of neighbors, the sun never sets and all big users like kettles and heat pumps kindly switch off as well. If either of those conditions stops being true, then either the frequency or the voltage will drop too much and the panels turn themselves off. In practice these balcony panels are not sufficient in the slightest to power a house, let alone an entire apartment building, and they will turn off almost instantly.
In any given moment the power grid must be 1:1 for production and consumption, and lots of smaller renewables pose a problem for big operators because they need to forecast and balance.
Is there something about German electrical systems that let's this just work? I feel like everything I've read about solar for the US isn't this simple.
In fact there is very little difference between plugging the AC side of a single panel into a socket and connecting a set 'the proper way' to your distribution panel. The only difference is overcurrent protection and maybe cable section size. But for single panels this could be a non-issue.
No, there is nothing special technologywise, it's a regulation thing. The thinking goes something like this: The million or two of balcony power plants installed in Germany help the installer's energy bill but the, let's be generous, 2 GWh per year produced are only a drop in the overall bucket, most local produced excess will not even leave your street before consumed. Furthermore, consider that Germany alone produces around 600 TWh of electrical energy per year. But Germany's grid is part of the European grid and yeah, 2 GWh don't even move the needle.
You need a two-way meter, so you'll have to communicate with your power company to get one installed beforehand, but otherwise it's as inconsequential to the grid as plugging in a vacuum cleaner or running a microwave oven.
AFAIK all inverters (except off-grid models) will refuse to work without mains power.
it's also technical requirement, you have to synchronize to existing sine wave.
the main reason such device is bad idea is that you might have power at exposed pins. In this case inverter will not produce any power until you already plugged into socket.
It would work with American electric systems; it's simply illegal to do that (ostensibly for safety reasons, actually for protectionist reasons (ok, maybe also because utilities don't want to build out grid-scale batteries and other smoothing solutions)).
Which could be privatized too, if the incentives were provided.
The safety reasons are actually valid. You can not safely turn off a power-topology with a N-to-N setup. The providers just cant life without that power..
The safety reasons are real though: when linesmen need to do work on the grid, it has to be depowered. This used to be easy to accomplish: just make sure the line is switched off from at the substation and you can be reasonably certain that the line is safe to work on. If Joe Random decides to send his solar power directly into the depowered grid, that would be a Bad Time for the worker involved.
"Protectionist reasons" sounds nice to people who already hate big corporations, but it doesn't make a lot of sense. When the grid is down, it's down. There is no revenue to protect at that point. The actual thing they might want to protect against is big solar farms competing away revenue from fossil fuel plants, but as you'll notice such solar farms are entirely legal.
>The safety reasons are real though: when linesmen need to do work on the grid, it has to be depowered. This used to be easy to accomplish: just make sure the line is switched off from at the substation and you can be reasonably certain that the line is safe to work on. If Joe Random decides to send his solar power directly into the depowered grid, that would be a Bad Time for the worker involved.
<yawn> This argument again? People have been saying the same thing about backup generators forever and it's just not true in practice.
From the POV of your solar or generator the resistance of the neighborhood is basically a short. Breakers will pop if generator and/or or voltage will collapse if solar. If you are out of sync and the grid comes back your hardware will be what leaves the chat, not the grid's
Linesmen are trained to ground their work first because the far bigger hazard to them is miscommunication among upstream coworkers. Better to liquify fuses or hardware than people when that happens.
If "everyone" had solar or a back fed generator it could be a problem but we'll cross that bridge when we get to it. And that bridge would be crossed procedurally on the utility/linesman side (grounding your work mostly already does but more would likely be desired). They're not stupid. They're not gonna trust their lives to the assumption that the hardware upstream and downstream is going to do what they expect.
>"Protectionist reasons" sounds nice to people who already hate big corporations, but it doesn't make a lot of sense. When the grid is down, it's down. There is no revenue to protect at that point. The actual thing they might want to protect against is big solar farms competing away revenue from fossil fuel plants, but as you'll notice such solar farms are entirely legal.
The protectionist angle is that if generation was more local rather than regional there would be much more competition because it would become more economically realistic for municipalities to strike out on their own and/or parter with each other and do so in order to shake off existing overpriced or incompetent utilities.
Well the inverters with which these solar systems work switch off within milliseconds when grid power goes down, so the problem you correctly identified is taken care of. There are also multiple redundant components to ensure this behavior.
> If Joe Random decides to send his solar power directly into the depowered grid, that would be a Bad Time for the worker involved.
You need a special inverter for it to not blow up when the grid is running, and even the cheap $80 grid tie inverters on amazon do this sort of checking before activating.
People with backup generators are also legally mandated to have switchgear that prevents them backfeeding into the mains grid when it is down, for the exact same reasons.
Here in rural Canada people with generators would often plug into a home outlet just a regular plug during a power outage. Not a good idea and depends on the circuit path if fuse or breakers. It's 120V AC to AC 60Hz anyway. Hey if it keeps power on, allows you to start the furnace, and not freeze, or keep pipes from bursting it will work.
Must be a gross simplification. The nearest power socket is not the right place for the decision where the power goes. You probably want all your sockets supplied with your own electricity, but not the outside world (which makes your distribution board the right place to connect anything).
I have a friend who works for the grid operator in our country. He says that if you, even for a few seconds, become a power generator (as opposed to a load) without being authorized to, they'll notice and there will be an investigation.
edit: Sounds like they do just plug in into the power outlet, and you're allowed to supply power back to the grid. Which makes sense, and is very different from what we have one country over.
It’s puzzling. Just the other day, it was reported that their power surplus was so significant that rates were even negative. So, why are end-users still paying high prices? Is it because of the distribution costs?
There's a big demand-supply mismatch throughout both the 24hr and the 365d cycle, while most consumer prices are flat throughout the day and the year. Solar panel owners are basically using the grid as a big battery, and miffed that electricity storage doesn't come cheap. (They'll discover the same thing if they buy home batteries to store their self-generated power.)
Actually, this is not the case in Germany, as we do not have net metering (feeding into the grid does not give you as much money as consuming from the grid costs).
Distribution is one of the costs. For discussion lets call it 10% of your power bill (someone can find real numbers, but that will work if like me you are too lazy to look it up). However there are other costs - you pay to maintain the backup systems that are not in use. I know of a generator installed in 1920 connected to a coal boiler built in 1880 - this horribly inefficient system (by modern standards) takes about 12 hours to turn on when needed - but gets regular maintenance including pressure testing just to be sure it works for the one time every 5 years when all the other backup systems are not enough - that is not free and you pay for the costs even though you rarely get power from it. (well you probably live in a different part of the world and so could not get power from it - but there is something like it that you are paying for)
The prices were already high before wind and solar power came to be (and for quite many years grid prices where among the lowest in EU, while consumer prices where among the highest). The high consumer prices for electricity in Germany are a result of grid fees, taxes, taxes on grid fees, taxes on taxes, and a lack of political will to lower those.
I live in the UK where we people point at the rest of Europe and say "why are our prices so high here when we have 50+% of our power coming from wind".
> The high consumer prices for electricity in Germany are a result of grid fees
Grid fees are a coverall for "making sure the whole thing runs", which in my mind covers "making sure there's gas (at least that's what we use in the UK) to cover the shortfall when it's not windy". The Gas stations need to be able to spin up to handle the demand, so it's an abritrage where you really want to maximise the amount of wind you use, while paying as little overhead to keep the gas ready to go. It's like being on-call, and having your on-call pay amortized into your regular pay.
Prices fluctuated a lot based on weather and demand. Seeing order of magnitude fluctuations day to day is not uncommon. Prices can be close to zero one day and hit record highs 24 hours later.
A friend of mine put solar panels on the roof of his house in France. He's got a 42U rack with shitloads of servers / more than 200 TB of disks / several 4090 GPUsrendering AI stuff etc., quite the beefy setup and yet at times, on certain days and for a few hours, the solar panel are powering it all (not just the 42U rack but the entire house, including the HVAC). Quite nice.
I'm German, and have installed a small (1.8kWp, 800W inverter) system myself. It's really pretty cool. It was really cheap (our system cost 750€ including installation material for the roof) and saves a lot of money (130€ since September). Ours will have recovered the upfront investment cost within the next 2 years. Our meter is currently turning backwards when we feed in, but will be replaced by a meter that doesn't (then, energy we feed back into the grid will be given away to the grid operator for free).
I forgot the coolest thing about this: We are currently transitioning from a demand-driven grid to a supply-driven grid. Previously, when more power was consumed, power plants upped their production by burning more coal, oil or gas. Now, the consumption needs to be upped when power is available via solar or wind, and reduced when it isn't. Balcony power plants do a very good job of educating and motivating people to do this.
> energy we feed back into the grid will be given away to the grid operator for free
Why would you do that? I'd rather sink all the surplus electricity into a cryptocurrency miner than just give it away to the grid.
You know, not everyone tries to profit from everything all the time.
Maybe not everyone but power grid operators absolutely do.
Don't give energy away to the operator, they don't (want to) give you energy for free either. Get something which can soak up excess energy - a battery, an electric water heater, whatever - and run that on whatever excess energy you have. Assuming you don't invest too much money in such a project you'll end up saving a bit more money and you'll avoid being fined for pushing energy into an already overloaded network once everyone and his dog have installed solar which pushes up the voltage from nominal 230VAC to somewhere around 245-250VAC (250VAC is the usual cutoff for inverters where I live (Sweden)).
I installed 14.5 kW of PV panels on the barn roof a few years ago and hooked them up to a 10 kW hybrid inverter. Hybrid inverters can divert energy (from the PV panels or from the net) to a battery which can be used at a later stage to feed consumers in the local installation or to backfeed to the net. Since we currently have a contract which allows us to sell energy at market rates we do not have a battery yet but I don't know yet what the next contract (in 2 years) will look like. Assuming that we can no longer sell at market rates I'll install around 60-80 kWh in battery capacity to soak up excess production and dump the rest in the water heater etc. If we ever get a hybrid or electric car/tractor/whatever I'll add battery capacity so as to be able to charge those with excess energy. By that time we'll be close to ready to go off-grid which is fine by me, electricity prices here in Sweden have skyrocketed due to the demand from (mostly) Germany for excess capacity since you shut down your nuclear power plants. The more transmission capacity is built in the Baltic, the higher our prices get.
A battery isn't profitable for me atm, and I have no problem giving the electricity away.
Do you have a source that shows that shutting down nuclear power plants has in any way influenced German power import? I'd doubt that. Power is imported when it is cheaper to import it than produce it ourselves (there has not been a situation yet where Germany couldn't meet it's own demand).
BTW, on the subject of batteries being too expensive it might be an interesting experiment to see how far you'd get using a common full sine wave UPS with a number of external batteries. Charge the external batteries using the inverter, pull power out of the UPS. Expenditure would consists of a UPS - you'll find these on auction sites, often without or with expired battery packs - and a number of batteries. A reasonably-sized UPS which can deliver a kilowatt or more often uses 24/48/72 volt battery packs, i.e. 2 to 6 lead-acid batteries in series. If you have a way of getting these for a reasonable price it may be worth experimenting with if you're the experimenting type (I am).
Our inverter is built for high-voltage batteries (120V to 580V) so I'm aiming for either using expired EV batteries or - once prices go down more - LiFePO4 battery stacks. As it stands prices are still too high which - calculated over the life span of the batteries combined with compound interest on the investment - makes power from such batteries cost around the same as power taken from the 'net. Battery prices are steadily going down so this situation should change, hopefully within 3 years they'll have gone down so far as to make it a worthwhile investment.
You're answering your own question here:
Power is imported when it is cheaper to import it than produce it ourselves
After shutting down the remaining 6, then 3 nuclear power plants it became cheaper to import power from Sweden - which used to be blessed with relatively low electricity prices due to to the large hydro and (diminishing) nuclear generation capacity - than to generate it in Germany. While this might have been positive for Germany and for electricity producers in Sweden it is a definite negative for electricity users in Sweden who have seen their prices skyrocket. As to the direct effects of the nuclear shutdown there's quite a bit written, e.g.
https://www.cleanenergywire.org/factsheets/qa-germanys-nucle...
4) What changed in electricity imports and why?
For the first time in many years, Germany became a net electricity importer in 2023. The trade balance for electricity switched from 21 TWh of exports to 22 TWh of imports in the same period. Imports have risen despite sufficient plant capacity in Germany to cover domestic demand entirely. In March 2024, the country announced the shutdown of seven more coal-fired power plant units after the winter, as they are no longer needed to guarantee supply security.
This leaves aside other costs involved with the nuclear phase-out [1] and the knock-on effects of the increased energy prices as well as lower guaranteed availability which is part of the cause of German deindustrialisation. If you doubt whether this actually happening I invite you to peruse a search engine of your preference on the subject which is more effective than me linking to a number of articles from many different sources.
[1] https://olivierdeschenes.weebly.com/uploads/1/3/5/0/13506865...
Related article from 3w ago: https://www.theguardian.com/environment/2024/dec/18/if-a-mil...
In india, atleast in my state, they let us add solar to our roof and let us give excess energy back to the grid. And they pay us back for the energy that is sent back to the grid
I believe that is such almost everywhere in the world. Alternatives for excess of energy tend to be much more expensive, unless there is no grid to connect to.
That's common on places where there isn't a lot of solar back-feeding the grid. When the amount gets big enough, it short-circuits the grid's cash-flow way before it becomes a nuisance electrically, and the rules change.
Places where they happens a lot run into issues since the sun doesn't always shine when people want power. People generally want to have a power bill of zero after installing these, but that cannot work out - they still need to pay for their share of the grid, plus whatever plan the grid as in place for nights. Depending on how many are doing this, it is possible to be in a point where there is more power than needed on the grid.
Live in an apartment in NYC and would love some way of turning our windows into solar panels. They only thing I've seen is a ~$100 device from a company called grouphug (no affiliation) whereby a small solar panel is stuck to a window via suction cup and can charge a phone (I believe it has a small in-built battery). Laudable but I wonder if it would return the investment.
It won't. These systems are quite large (a single solar panel is approximately 1.2m by 1.7m (4 to 6 ft ?) and even if you put it outside with direct southern exposure and no shade it takes 2-5 years to recoup the investment cost. In the US, you pay less for electricity (in most places) so it would take longer. Behind a window, generated energy will be way less.
This seems about the perfect energy technology: affordable, self install, clear ROI, no permits necessary, no distorting subsidies.
I very much want one of these in Finland, but our provider KSOY said no no no.
Posing the question, is there a valid technical reason or is it just institutional conservatism and inertia ?
Operating electrical power grids requires a very careful balance between production and consumption. Long term trends are regulated on the consumption side through pricing, short term jitter is regulated on the production side through switching power plants on and off.
Traditionally, a power grid only had medium and large power plants, and they are not only connected to the power grid but also a control network. Adding many small power generators poses a problem in how you communicate and coordinate with them.
"Connecting Solar to the Grid is Harder Than You Think" https://www.youtube.com/watch?v=7G4ipM2qjfw
Although 800w per household shouldn't make a difference for the grid.
800w for your house won't make a difference. Multiply by millions of households and that is real power that will make a difference.
800w is the maximum being produced, and not all of it will be fed into the grid. And it is unlikely that millions of households have all installed powerplants which are all oriented in the same direction and not shaded.
Germany is 84 million people. If 1% have solar and they currently average to 400 watts (half capacity from their 800 watts because of positional and shading issues) that is 33 Gigawatts. That much power if not managed will cause problems for any grid.
These things just plug into a power outlet. Requirement for Austria is a Smart Powermeter, because the old, analog ones would run in reverse if the solar panels produced more then you are currently using. They may not exceed 800W and are required to turn off if no power grid is detected, e.g. during a power outage. Apart from that, just institutional conservatism and inertia as far as I know.
Because they are potentially deadly in certain failure states. Normally system you expect system to be dead when main switch is turned off. But in this case something might be feeding in power. Same goes for over current protection. You really do not want power when you expect there to be none. Even if you should always check.
This is not really an issue. The inverters used in these cases rely on an existing power supply for synchronization with the electrical grid. If there is no power on the socket, the inverter has no means to generate a sine wave on its own and does not provide power on its cable.
This is true (as far as I know) for ALL inverters, apart from "off grid" solutions, so workers can turn off power on a street level. If that wasn't the case, there would be no way for technical staff to make sure that lines going to multiple homes (with solar) are powered off.
I can how it would not switch on if line power is gone. But what if it is on already, there are not many loads on, and the mains go down? Does it switch off? How does it know?
It watches the incoming AC waveform and matches that. If there is no waveform it has nothing to match and so it shuts off.
READ THE OTHER REPLIES FIRST. I'm going to assume you did as they are right about what this can't happen.
When you backfeed like that your neighbors will draw on your power - but they will attempt to draw more than you can provide and so your circuit breakers will trip. The only way backfeeding could be an issue is if you have a very large generator and the area islanded is only a couple neighbors such that the total power use is less than the theoretical max of your house.
That said, linemen are trained to either treat all wires as live or short them to ground. They can never be sure they are not in that rare exception case and mistakes can be deadly.
Balcony solar requires the 50Hz of the energy grid. If you turn off the main power they will stop feeding into the system.
So if enough of your neighbors have these panels then the grid never gets turned off.
Technically probably yes, provided you had millions of neighbors, the sun never sets and all big users like kettles and heat pumps kindly switch off as well. If either of those conditions stops being true, then either the frequency or the voltage will drop too much and the panels turn themselves off. In practice these balcony panels are not sufficient in the slightest to power a house, let alone an entire apartment building, and they will turn off almost instantly.
[dead]
In any given moment the power grid must be 1:1 for production and consumption, and lots of smaller renewables pose a problem for big operators because they need to forecast and balance.
I got the feeling that people were just not telling their electricity provider that they were doing this.
Have your cake and eat it ? https://solarbringer.de/solar-inselanlage-mit-netzunterstuet...
Yes, this is exactly my configuration! 3.5kw panels, 9kwh battery. Saves at least 1/2 of the daily power usage.
> the panels simply plug into power sockets
Is there something about German electrical systems that let's this just work? I feel like everything I've read about solar for the US isn't this simple.
In fact there is very little difference between plugging the AC side of a single panel into a socket and connecting a set 'the proper way' to your distribution panel. The only difference is overcurrent protection and maybe cable section size. But for single panels this could be a non-issue.
Source: i installed a set of solar panels myself.
Well, that's if you have a single-phase installation.
But that overcurrent protection is huge. Even more if your house walls are flammable.
No, there is nothing special technologywise, it's a regulation thing. The thinking goes something like this: The million or two of balcony power plants installed in Germany help the installer's energy bill but the, let's be generous, 2 GWh per year produced are only a drop in the overall bucket, most local produced excess will not even leave your street before consumed. Furthermore, consider that Germany alone produces around 600 TWh of electrical energy per year. But Germany's grid is part of the European grid and yeah, 2 GWh don't even move the needle.
You need a two-way meter, so you'll have to communicate with your power company to get one installed beforehand, but otherwise it's as inconsequential to the grid as plugging in a vacuum cleaner or running a microwave oven.
AFAIK all inverters (except off-grid models) will refuse to work without mains power.
it's also technical requirement, you have to synchronize to existing sine wave.
the main reason such device is bad idea is that you might have power at exposed pins. In this case inverter will not produce any power until you already plugged into socket.
It would work with American electric systems; it's simply illegal to do that (ostensibly for safety reasons, actually for protectionist reasons (ok, maybe also because utilities don't want to build out grid-scale batteries and other smoothing solutions)).
Which could be privatized too, if the incentives were provided.
The safety reasons are actually valid. You can not safely turn off a power-topology with a N-to-N setup. The providers just cant life without that power..
The safety reasons are real though: when linesmen need to do work on the grid, it has to be depowered. This used to be easy to accomplish: just make sure the line is switched off from at the substation and you can be reasonably certain that the line is safe to work on. If Joe Random decides to send his solar power directly into the depowered grid, that would be a Bad Time for the worker involved.
"Protectionist reasons" sounds nice to people who already hate big corporations, but it doesn't make a lot of sense. When the grid is down, it's down. There is no revenue to protect at that point. The actual thing they might want to protect against is big solar farms competing away revenue from fossil fuel plants, but as you'll notice such solar farms are entirely legal.
>The safety reasons are real though: when linesmen need to do work on the grid, it has to be depowered. This used to be easy to accomplish: just make sure the line is switched off from at the substation and you can be reasonably certain that the line is safe to work on. If Joe Random decides to send his solar power directly into the depowered grid, that would be a Bad Time for the worker involved.
<yawn> This argument again? People have been saying the same thing about backup generators forever and it's just not true in practice.
From the POV of your solar or generator the resistance of the neighborhood is basically a short. Breakers will pop if generator and/or or voltage will collapse if solar. If you are out of sync and the grid comes back your hardware will be what leaves the chat, not the grid's
Linesmen are trained to ground their work first because the far bigger hazard to them is miscommunication among upstream coworkers. Better to liquify fuses or hardware than people when that happens.
If "everyone" had solar or a back fed generator it could be a problem but we'll cross that bridge when we get to it. And that bridge would be crossed procedurally on the utility/linesman side (grounding your work mostly already does but more would likely be desired). They're not stupid. They're not gonna trust their lives to the assumption that the hardware upstream and downstream is going to do what they expect.
>"Protectionist reasons" sounds nice to people who already hate big corporations, but it doesn't make a lot of sense. When the grid is down, it's down. There is no revenue to protect at that point. The actual thing they might want to protect against is big solar farms competing away revenue from fossil fuel plants, but as you'll notice such solar farms are entirely legal.
The protectionist angle is that if generation was more local rather than regional there would be much more competition because it would become more economically realistic for municipalities to strike out on their own and/or parter with each other and do so in order to shake off existing overpriced or incompetent utilities.
Well the inverters with which these solar systems work switch off within milliseconds when grid power goes down, so the problem you correctly identified is taken care of. There are also multiple redundant components to ensure this behavior.
> If Joe Random decides to send his solar power directly into the depowered grid, that would be a Bad Time for the worker involved.
You need a special inverter for it to not blow up when the grid is running, and even the cheap $80 grid tie inverters on amazon do this sort of checking before activating.
How is that different than people having backup generators?
People with backup generators are also legally mandated to have switchgear that prevents them backfeeding into the mains grid when it is down, for the exact same reasons.
Here in rural Canada people with generators would often plug into a home outlet just a regular plug during a power outage. Not a good idea and depends on the circuit path if fuse or breakers. It's 120V AC to AC 60Hz anyway. Hey if it keeps power on, allows you to start the furnace, and not freeze, or keep pipes from bursting it will work.
Must be a gross simplification. The nearest power socket is not the right place for the decision where the power goes. You probably want all your sockets supplied with your own electricity, but not the outside world (which makes your distribution board the right place to connect anything).
I have a friend who works for the grid operator in our country. He says that if you, even for a few seconds, become a power generator (as opposed to a load) without being authorized to, they'll notice and there will be an investigation.
edit: Sounds like they do just plug in into the power outlet, and you're allowed to supply power back to the grid. Which makes sense, and is very different from what we have one country over.
[dead]
It’s puzzling. Just the other day, it was reported that their power surplus was so significant that rates were even negative. So, why are end-users still paying high prices? Is it because of the distribution costs?
It is because of merit order. The most expensive generator of energy sets the price for all the energy.
https://en.wikipedia.org/wiki/Merit_order
There's a big demand-supply mismatch throughout both the 24hr and the 365d cycle, while most consumer prices are flat throughout the day and the year. Solar panel owners are basically using the grid as a big battery, and miffed that electricity storage doesn't come cheap. (They'll discover the same thing if they buy home batteries to store their self-generated power.)
Actually, this is not the case in Germany, as we do not have net metering (feeding into the grid does not give you as much money as consuming from the grid costs).
Distribution is one of the costs. For discussion lets call it 10% of your power bill (someone can find real numbers, but that will work if like me you are too lazy to look it up). However there are other costs - you pay to maintain the backup systems that are not in use. I know of a generator installed in 1920 connected to a coal boiler built in 1880 - this horribly inefficient system (by modern standards) takes about 12 hours to turn on when needed - but gets regular maintenance including pressure testing just to be sure it works for the one time every 5 years when all the other backup systems are not enough - that is not free and you pay for the costs even though you rarely get power from it. (well you probably live in a different part of the world and so could not get power from it - but there is something like it that you are paying for)
The high prices people pay is the cost of having power when it’s not windy/sunny
The prices were already high before wind and solar power came to be (and for quite many years grid prices where among the lowest in EU, while consumer prices where among the highest). The high consumer prices for electricity in Germany are a result of grid fees, taxes, taxes on grid fees, taxes on taxes, and a lack of political will to lower those.
I live in the UK where we people point at the rest of Europe and say "why are our prices so high here when we have 50+% of our power coming from wind".
> The high consumer prices for electricity in Germany are a result of grid fees
Grid fees are a coverall for "making sure the whole thing runs", which in my mind covers "making sure there's gas (at least that's what we use in the UK) to cover the shortfall when it's not windy". The Gas stations need to be able to spin up to handle the demand, so it's an abritrage where you really want to maximise the amount of wind you use, while paying as little overhead to keep the gas ready to go. It's like being on-call, and having your on-call pay amortized into your regular pay.
It's a give and take between profits and taxes, a wonderful symbiosis of neoliberal politics and the oligopoly.
Prices fluctuated a lot based on weather and demand. Seeing order of magnitude fluctuations day to day is not uncommon. Prices can be close to zero one day and hit record highs 24 hours later.
A friend of mine put solar panels on the roof of his house in France. He's got a 42U rack with shitloads of servers / more than 200 TB of disks / several 4090 GPUsrendering AI stuff etc., quite the beefy setup and yet at times, on certain days and for a few hours, the solar panel are powering it all (not just the 42U rack but the entire house, including the HVAC). Quite nice.
[dead]