Several recent HN posts about "time" and these correlate superbly in relation to the now obvious, to nearly all, global energy issues. Those proactive in a reactive world are often mocked and laughed at until as such passage of time is achieved for those only reactive to learn of the proactive's hindsight choices. For those in the United States aware of the 'behind the scenes' energy grid issues this insight reflects that prices will not be dropping for those electrons we all so depressively require daily just like our air and water. Energy grid decentralization is occurring with the actions of each individual and this article supports exactly that because no one alive can survive in our modern world without those electrons. "Necessity is the mother of invention" only now resonates for some while the futurists here that acted long ago acutely understand this growing trend.
(I note that in the alternate universe where Ed Miliband became PM because he didn't eat a bacon sandwich, we could have had this a decade ago. It is embarrassing to be beaten on environmentalist regulatory efficiency by Germany)
British industry and standards bodies think this is an unsafe plan.
Of course they would because it's work being taken away from them but it would be allowing people to plug generators into ring finals with unidirectional breakers. It's not even guaranteed that the circuit is protected by anything newer than fuse wire or an MCB. No guaranteed earth leakage detection. No guaranteed surge protection. Relying on the cheapest inverters to sync frequency accurately. And
I have more faith in German standards and work ethic than our own.
I find it interesting because often the best way to achieve a safe building code is to learn by allowing with basic guard rails and iterating as things happen. This isn’t ideal for the rare individual impacted by the “things happening,” but collectively we refine and iterate. Our current standards weren’t arrived at by navel gazing - we got the codes we have by experience. It’s hard to realize that from the present that you can’t reasonably learn without doing and by constraining without learning prevents growth and learning.
Are there lessons on safety that need to be learned here? We already know what the happy path looks like, and we've plenty of lessons on what the unhappy path will look like.
It isn't as if electric charge coming from balcony solar panels is some new magical-seeming type of electricity.
Safety is statistical and depends on human behavior. Unexpected behaviors might appear. For example some places require a power outlet on kitchen islands because with out, people will use cords to the wall which creates tripping hazards.
Also, why do wires have to be fixed to joists every 300 mm? It's not about the electrons.
The situation in germany is essentially the same, but that's why net supply by these is limited to 800 W. I don't think anything changes w.r.t. earth leakage, why would the presence of the solar supply change anything from the RCD and fault point of views, respectively?
Not expert but one difference is that in Germany the standard wiring is radial circuits with 16A MCBs while in the UK it's ring wiring with 32A MCBs.
So in the UK we have 2.5mm^2 wires in a ring on a 32A MCBs... Of course a 2.5mm^2 wire is rated ~20A so any issues with the ring (sockets still work since connected from the other branch) can burn the wire before the MCB trips...
The "standard" wiring is 1.5mm² on 16A MCBs which are rated to trip at 1.13-1.45x nominal current (so 18-23 A). So this is already mildly improper because you can pull elevated currents continuously and dramatically shorten the life of the insulation.
He also removed the effective ban on onshore wind construction that was introduced a month after he lost the election, restarting after a decade of lost opportunity.
This Trump-level idiocy that is just never mentioned, even as people blame the gas burned in england on windy days as a cost of wind curtailment, when the curtailment is more a like a third of the cost. Burning gas to power people who chose not to build turbines is the other 2/3rds.
In the alternate world that is tens of billions of gas costs avoided to date and tens of billions more in future.
That seems rather dumb. I wonder why they blocked the Ming Yang thing in Scotland? The UK seems to make quite a lot of dumb energy decisions like blocking UK North Sea gas and then buying North Sea gas from Norway.
Yes it is rather 'dumb'. Apparently the policy is to reset relations with the EU so perhaps selling out to Siemens is deemed preferable, or perhaps they got the usual friendly phone call from Washington D.C, it is difficult to follow. And that's the point: Where is the plan? Where is strategic thinking?
> I note that in the alternate universe where Ed Miliband became PM because he didn't eat a bacon sandwich, we could have had this a decade ago
I read what is happening in exactly the opposite way. To me it shows that Milliand and the government at large do very little with no strategic thinking and no plan (same as the guys before in fairness but this government was supposed to be soo different...) and, in this case, is only reacting in a panic after almost 2 years in office to the pressure of "doing something" because of the Iran war, while also being told (slight mitigating circumstances for Milliband) that it mustn't cost anything. I always picture scenes from The Thick of It/ In the Loop when I imagine how they come up with 'ideas'.
I'm fairly certain securing one's household's access to energy independent of rate increases triggered by a combination of aging infrastructure and data center power demand doesn't have a lot in common with tech bros attempts at reinventing trains badly from first principles but I'm open to hear the argument. Care to unpack that?
> And don't let perfect be the enemy of good. Yes there are times when solar doesn't produce energy, but there are also times where it OVERproduces.
When solar OVERproduces you have to literally pay someone to consume that energy, most probably wind farms, which could be producing energy instead. So you pay actually twice. When the solar underproduces, you need to bring in alternative sources, but those now have to cover all their fixed costs and generate return on investment over this limited timeframe, which means the actual backup prices hit stratospheric levels.
What's the actual cost of solar with actual net-billing?
Home installations just cut it off. In both of these cases.
I did my own battery backed installation. When I'm underproducing I can shed load (I turn off my AC - almost always that's enough, and it's automated by relay). When I'm overproducing (ex - my battery is full and my load is still not enough to consume input) I just don't let the panels generate more current than I can consume.
Managing grid scale power is different concern, and not particularly relevant to small household generation. Especially not relevant in the 800W category for "balcony solar" (which is much smaller than what I'm working with).
Solar is fucking coming, whether you continue to shove head into the ground or not.
It's just way more affordable. Getting easily more affordable as batteries continue to improve.
I honestly doubt I'll still be connected to a local utility grid for electric 10 years from now, and I live in a region of the US that has considerably cheaper grid power than most areas.
When it's too worn out for car use (SoH around 60-70%), it's still perfectly enough to run _everything_ in my house for multiple days - except for the electric sauna, and I'm smart enough to turn it on if there are production issues :D
There's a reason why EV's will never be as cheap as the cheapest ICE shitbox. Just the bare metals in the battery are worth thousands when recycled, even more if the battery is still viable.
Curtailment is when an energy company has successfully bid on delivering electricity for the next block of time (an hour, for example) but it can’t provide that agreed amount of power because it would overload the grid. There are various reasons why that would happen: faults and unexpected lack of demand, for example. In that case the company is paid for the energy it was contracted to deliver, only for that period of time, even though it did not provide power.
It is wrong to say that overproducers HAVE to be paid. They don’t. They only have to be paid if there was an agreement to buy that power but for whatever reason the grid can’t take it. Normally if there is a generation surplus, the cheapest companies will win the bid to provide power and the others will simply not be paid.
Here in Finland electricity prices can drop to under 1c/kWh due to renewables, basically every time it's sunny and/or windy electricity is practically free (the transfer costs are static though).
A few times the price has actually been negative, people got paid for using electricity due to overproduction =)
There will be connected batteries in every home solving this problem faster than the fossil fuel lobby can come up with a new talking point about why it’ll never work.
> When solar OVERproduces you have to literally pay someone to consume that energy,
Can't we just throttle the solar panel? In a worst case, you just pull the plug. It's not like a nuclear power plant which needs to be shut down carefully, or am I misunderstanding something?
Not sure how is situation with home installations, factory i work for runs 150kw plant for our own consumption and don't bother with selling, but i know that we can set up how much we want/are allowed to feed back.
I'll question it. Why does it exist? Why can't we just shut off the panels or dump excess energy into a metal rod? Why do we need to have a buyer at all?
It's not a buyer, people are paid to take the energy that would otherwise be wasted. And when energy use is shifted it means you need to generate less later, saving money.
The people who pay that cost to the people using the energy are people running energy generators that suffer wear and tear when they ramp down.
Or sometimes it's a subsidy for the use of clean energy being passed on to ensure the clean energy is actually used, not wasted.
Because otherwise the incentive structures for solar-as-baseload, sweeping the actual cost on the consumers, collapse. The system is built on putting equality sign between oversubscribed solar and coal/gas backups during times of undersubscription.
> When solar OVERproduces you have to literally pay someone to consume that energy, most probably wind farms, which could be producing energy instead.
You don't have to do this with solar, you can just disconnect the panel and have it go a bit hotter. For producers that have a long-ish bringup time, yes, you might need to do this at time.
The situation is slightly complicated by dispatch order, and domestic solar isn't usually dispatchable at all. Grid-scale farms are.
Wind farms don't consume energy, but there is a real issue with how often they have to be "curtailed" (paid to turn off). That is to a great extent due to issues with grid connectivity between Scotland and the rest of the UK, which are (slowly) being worked on.
Wind curtailment is the deliberate reduction of electricity output from wind turbines, despite their capability to generate power under existing wind conditions. This practice is typically implemented by grid operators to maintain the stability of the electrical grid or to address specific operational constraints.
"paid to turn off"
Wind energy providers in some countries are compensated for curtailment, this a form of subsidy for renewables. It can be payed directly by the goverment, or it is added to the price of electricity for consumer.
Cheap home solar installations usually have a disconnect- do they not use those in larger scale installs?
I'm also surprised they aren't using batteries to capture overproduction. They've been clutch in the US, and we're not exactly pushing the envelope of green energy nowadays
When there's an OVERproduction of energy, that really means there's an UNDER-availability of storage. Battery tech continues it's march towards cheaper prices, and alternatives such as thermal storage are making inroads as well.
It borders on criminal to have abundant energy production be disservice.
I'm no energy markets analyst, so take this with a grain of salt, but I think the next major breakthrough for solar (not the slow, inevitable rollout we're seeing now) will be when somebody figures out an economical way export this periodic overproduction. There is basically never a time when humanity as a whole has an overproduction of free energy, but at present we also don't have a way to make money turning this surplus into a tradable product (like oil, coal, LNG, etc.) because all the electric-powered processes for making such products (ammonia, methane, primary aluminum production, etc) require big hunks of capital equipment that lose money unless they're operated more or less continuously. Battery, thermal, pumped hydro, etc. help here, in that enough of it can theoretically turn off-and-on solar/wind power into a continuous load to power your aluminum smelter or whatever.
Even better though, would be a cheap electrically operated methane plant that you could afford to run intermittently. This, plus a peaker natgas generating plant make, effectively, a battery of infinite size, or you can sell it to any of the many eager buyers of natgas.
Building a small, prefab, plant like this, if possible, would seem to be mainly a problem of scale, and therefore it seems likely that China will get to it pretty soon.
Inverters can be configured with export limits to limit, or entirely halt, energy exports based on market or grid signals. Term of art is "curtailment."
This is literally the only sane usage for hydrogen outside of industrial uses, when you have a massive excess of renewables, use it to turn water into pressurised hydrogen.
And when the prices go up, you run that through a grid scale fuel cell and feed it back to the network.
Used 240w modules built in 2010-2012 are worth $60-100 CAD at the moment in small quantities. There will be hundreds of thousands hitting the market (as long as they didn't hit the ground with careless removals) in ~2030+ as microFIT contracts in Ontario expire.
There is no clear path to switching these arrays to Net Metering, as of yet. Prepare for all sorts of unrecycled solar panels and potential loss of renewable capacity that is already installed.
Net metering is really, really smart when the installed base is small relative to the fossil fuel power plant capacity. But it doesn't scale forever. Once it gets up towards 20-40% of the fossil fuel capacity, it goes from an asset to a liability.
Suppose I have a 100MW gas turbine. And suppose there's 1MW of solar installed in my generation network. I don't really care if I sell 80MW at noon and 90MW around dinner time and 50MW through the night, or if instead it's 79MW at noon and 91MW at dinner and 51MW at night. The gas costs about the same irrespective of when I burn it so a bit of a fuel shift doesn't really matter.
But take that 1MW and turn it into 20MW and suddenly we go from 80MW at noon to 60MW at noon, 90MW at dinner to 110MW at dinner and uh oh. You see the problem? Whatever losses I endured at noon I don't get to make up for at dinner because my plant only goes up to 100MW and now we're not just shifting when we burn how much fuel, we're literally having to shift the power generation to a different plant.
Is this example precisely accurate? Absolutely not. But it helps you get a feel for the problem of net metering at scale. The grid can act as a battery for a few % of total generation, but by the time you hit some number, maybe 20% maybe 40% net metering turns from a cool math trick to a real cost on the grid.
Net metering only makes sense as a way to incentivize solar installations. Looking at the economics, it's not something any utility would offer willingly.
It's like if the grocery store let you give them milk for a credit at full price. (Let's ignore the sanitary/health/quality issues that would come up.) You decide to buy a cow and you drink that milk. Sometimes you need more than your cow can give so you buy extra from the store. Sometimes you need less and you sell the extra to the store. Long term, you use as much as your cow produces on average, so you pay the store nothing. But the store has provided a valuable services to you and has incurred expenses in doing so. They have to keep the lights on and maintain a building and pay workers to handle your transactions but they make no money from you. The only way it would work at all is if they made enough money from their non-cow-owning customers to make up for it, and that can only take you so far.
Buildings get torn down. Roof needs a replacement and the owner doesn't feel like it is worthwhile to redo the solar install for panels that only have 5 years of warranty left, or maybe they want to replace them with higher power models with a fresh warranty. There are any number of reasons why someone might need to offload otherwise functional solar panels.
Currently used solar panels are a hot commodity, with many groups selling them by the pallet, because 10 year old solar panels are still efficient enough to easily pay for themselves. Very few installations will care about specifically how many panels they want, they just want a nameplate output per dollar figure.
Old inverters might not have a second life though.
The UK previously didn't allow small plug in solar panels (the kind that you just plug in to a mains socket) due to, I believe, safety reasons. This has changed within the last few days https://energysavingtrust.org.uk/solar-roadmap/
I believe it’s only legal in Utah so far in the US: they legislated it last year, and apparently half the country is expected to pass a copy-paste version in their next sessions
It hasn't changed... yet. The media noise is because the government has announced that they were reviewing current rules with the aim of allowing "balcony solar" by the end of the year.
For european individuals, yes. For european nations, not in the least. They try to avoid independent consumers and producers of energy with all the regulations they can throw to them.
A quick check of OBI (our main home-improvement chain) shows that I can get that 800w "balcony" plug-and-go system for 300-600 EUR depending on the exact panels and inverter I want, and it's all pre-approved. I have fill in a simple, free form online announcing that I've done so or am planning to, and I'm now technically an energy seller - my local utility pays some for power fed back into the network (not nearly the rate they charge for delivering power, but better than a poke in the eye with a sharp stick). If I don't want to accept 0.08 EUR/kWH, I'm free to plug in a battery for any excess. Our base load when I have my work computer and monitor on during the day is somewhere in the neighborhood of 300w, so I think this would work out well for us. I need to get off my bum and do it.
Shockingly unbureaucratic for Germany.
There is, as one could imagine, somewhat more burden for larger systems that require the involvement of someone who is actually an electrician, but I don't want my neighbors to be able to DIY fire hazards.
What nations are you talking about? E.g. in Germany, you can buy up to 7kW of panels, screw them onto your roof, wire them up with controller and battery and feed up to 800W into local grid, no one is gonna stop you or anything (only thing you need to do is register online with the grid operator if you have >2kW of panels).
Legislation is, in fact, specifically made so people (i.e. landlord) actually can't easily stop you from doing this.
Can anybody explain how these plug-in solar panels work? I am suprised that it's possible to just plug them in to your wall socket.
For instance, isn't it complicated to have their output be in perfect sync with the frequency that comes in via the electricity net? Because to me it seems that if they won't, you will have lower benefits or even a net minus after plugging it in.
> isn't it complicated to have their output be in perfect sync with the frequency
Not especially, given that the inverter has a microprocessor in it. All it has to do is measure the phase of the existing grid.
I don't have references for how it's actually done, but one obvious approach is simply to wait at each zero-crossing for a new half-cycle to cross a voltage threshold before turning on the output. This also implements the requirement to drop out if the grid goes away. It is probably also possible to measure during the "off" side of inverter output PWM, in the same way that variable frequency motor drivers work.
I guess if you can solve phase alignment then another big problem is grid capability?
If everyone plugged one in, could the transmission network reliably deliver the power generated where it's needed? I thought that was a serious long term challenge for utilities wrt solar.
Not a specialist, just from what I heard: There are two things that make it work. First they are not really "independent" like the title says. They sync with the grid frequency. If the grid is down they shut off for safety. The other reason it works is that the grid power inside the home is just what you get as incoming power 〜230V. For example, I think in the US you get 240V or so delivered to your house, but 120V from the plug.
Typically, you have "dumb" panels connected to a mppt-controller/charger/inverter box which is connected to batteries and and electrical plug. This controller tunes voltage/current that is taken from the panels, optionally manages the attached battery and measures and feeds into the grid connection.
Some systems are capable of running in isolation from grid (providing 230V AC on their own), but this is less common and often unnecessary.
My understanding is that plug-in solar inverters do sense what is coming from the grid and phase-sync to it with a PLL, and also adjust voltage accordingly.
"Many consumers want to know how long it will take them to make back the upfront costs of solar"
my answer is that the payback is imediate, right from the first moment watching as energy is generated out of thin air, and the sudden relief from getting off the energy angst missery-go-round, and the sheer borring inertness of solar pv as it does the thing with zero detectable effort, is gratifying and relaxing in a way that money never gives.
I will add that solar pv is increadably robust, and damage tollerant as well, you can drive a claw hammer through a panel, and while it does not improve the performance, the degradation is actualy not that much, and it will continue to function for years
It’s already possible for consumers to know that, I worked on the software that powers the tools that tell US consumers this at Genability ca 2015.
As far as I know, they never cracked the European market, so if you’re interested in working on that, I’m currently available for hire! Info in profile :)
We just got solar panels and a battery installed on our house. I try to be hard-headed about the economics when planning, but I have to say the _experience_ of having done it is exactly as you describe.
The other thing it made me is angry at the political morass that these things seem to be in.
At a technical level I understand the ‘base load’ arguments, but we are throwing away _so much energy_ that’s just there for the taking by not having these everywhere. On most days, our house (in Western North Carolina) gets enough energy from the sun that we net-export to the grid - and we have an EV! There’s just no need for the massive amounts of carbon we are spewing into the air - the energy is just falling onto us!
In the future, providing we’re still around, we’ll look back at a time when we could’ve been getting all our energy needs from just the sun (and wind etc.) and shake our heads in disbelief at those who fought against the idea that we should even think about efficiently using it so viscerally.
The mindset shift towards “how many hours of computer usage did that one panel enable” is like the mindset shift from learning calculus, in some ways. Not quite a paradigm shift, but you gain a new appreciation for conservation of use when it’s a difference between choice of $/kW/hr and “wow, the panel powered that for most of the day”.
At the same time, many people will just use a solar calculator or watch or yard lights etc, oblivious to it all.
Show people a solar powered laptop, a solar powered phone, or a solar powered tablet, then they will be impressed.
Remember the craze about solar powered car competitions?
permacompute + solar would make for quite the $100 laptop competition.
Is it immediate? Sure, there is satisfaction that you are using 'free' electricity. But it does have an upfront cost. I calculated that it would take over 11 years to recoup the investment based on our current usage. Given we already get cheap night-time rates to charge the car and run appliances, it is hard to justify.
Like many UK houses, we have gas central heating too. I guess if we had a battery too (more investment) then we could switch to using electric oil-filled radiators, though they would not heat the whole house. And we could install a hot water tank.
I guess for new builds there is a real opportunity, but for an existing household I'm struggling to see how it works - and I want it to!
I don't think it ever makes sense to switch to electric radiators. It might make sense to switch to a heatpump, but you need to avoid being hugely overcharged by the installers and there are flow issues if you have 8mm piping.
This ROI calculator looks reasonable: https://ukcalculator.com/solar-panel-roi-calculator.html - note that it subtracts the install cost for you, so any case where the final figure is positive is profitable. But of course that depends on whether grid prices go up or down in the next decade ...
Well France did move to electric everything (cooking, hot water, heating) in the past thanks to ample nuclear electricity production (and possibly not too harsh winters). Unfortunately they let their nuclear programme decay and are struggling now (EU grid integration does not help)...
I think a big part of the push to install heat pumps now is that it is understood that electricity production is in dire straights, taking into account that the transition to EV requires a lot of electricity.
>> "Many consumers want to know how long it will take them to make back the upfront costs of solar"
> my answer is that the payback is imediate,
So if I pay $35k for an install, I get a $35k check the first time I connect it to the grid? Pretty sure it doesn't work that way. But it would be a nice subsidy from the government if they were really motivated.
I guess you're saying you start to feel good and validated to have spent the money by seeing _some_ savings every billing period. It's hard to argue with feelings of course, but that's not not the original concern. People want to know how long is it going to take: 1, 5, 10 years or ... never (if panels degrade or break before it will never pay off) to pay off their investment.
"Suddenly" is horrific evidence that the government has no idea how to do long-term plans.
Wait until you tell them you can run cars entirely on electricity from a solar farming. I'm sure they will ignore you until the price of diesel reaches four-digit territory. 1000p today? If only we didn't have to pay these incredible prices, what a miracle that would be..
It's not that government has no idea, it's that around the world, too many "leaders" are directly or strongly indirectly being enriched by the fossil fuel industry and their support industries.
So politicians have a choice: do what's right for the people, or gain more power/money for themselves. Not every one of them chooses poorly, but enough do that it is difficult for real progress to be made.
Don't forget the truly staggering amount of voters who seem to be ideologically opposed to energy independence and self delusion to support those bought politicians.
People earnestly and genuinely spout "But the birds" to wind installations. Why are they so intent on taking any possible excuse? Why do they need to have an opinion on something they know nothing about?
I once read an article that in Berlin the sewage system is flushed with fresh water because too many people have installed water saving toilet flushers. So plenty of people bought these water savers and now the price of water has gone up because the water that is directly flushed needs to be paid too.
The 'balcony power stations' are the same thing. They get subsidised, and you even get a fixed kWh price when pushing into the grid.
The problem is that in the end it will become more expensive for everybody because at times you have a surplus driving the whole sale electricity prices into the negative while still paying fixed prices for injection into the grid.
To make this economically viable, you have to have everyone paying spot prices. Everything else is just green ideology driven inefficiency.
Just to make it clear, I think renewables are an important option for the future. But to make them a viable option of the electricity energy mix, supply and demand, storage and grid capacity need to be taken into account.
Last not least, there is plenty of low hanging fruit to drive CO2 emissions down: drive up the truck tolls. Currently you have potatoes farmed in Germany, driven to Poland to get washed, transported to Italy to be converted to french fries and transferred back to Germany into the super markets.
Same goes for home office, during Covid it was possible for many workers to continue with their work. Does an accountant need to drive to an office every day? Nope. How many business trips could be replaced by a video call?
If the CO2 emissions problem is to be solved rather sooner than later, the money has to be spend efficiently as there isn't enough of it.
The price of water has gone up for a multitude of factors. One of them is water savings in general, but not primarily because the sewage system requires regular flushes. The reason is that water gets paid per qubic meter and includes a fresh water and a waster water component. The assumption is that almost all fresh water you use ends up as waste water. Now, the grid has a very substantial fixed-price component that's largely independent from the actual current volume being used. Putting pipes in the ground and maintaining them there is an actual costly endeavour. If water use now drops, and the baseline cost remains stable, then it's entirely expected that the price per volume rises. It's simple math. The same baseline cost needs to be brought in via less volume.
This will also happen to people that use residential gas. As less and less people use residential gas, the maintenance of the gas network gets distributed among less and less customers.
> The 'balcony power stations' are the same thing. They get subsidised, and you even get a fixed kWh price when pushing into the grid.
They are subsidized on purchase, but the price they get when pushing energy into the grid is by default fixed at 0. The network accepts the power, but there's no payment. It's also capped at 800W delivery, meaning that at peak power generation, you'd earn a whopping 5 cent an hour with the current subsidy for full scale solar power. So in practice, the only benefit owners have is that they draw less power from the net which is much more attractive because of the pricing structure. You can, optionally, register your balcony power station as a regular solar power plant, but then you're subject to a whole bunch of rules and regulations (for example you need a suitable elctricity meter etc.). This option is generally not attractive for such small power generations.
Fundamentally, though, the same issue as with the water and gas network exists with all localized (solar) power generation. If more and more people use the grid only as a backup, or for winter energy needs, then the overhead of maintaining the grid will have a larger cost contribution to the total cost of electricity.
As soon as everybody is paying spot prices, balcony power stations are not economically viable anymore. Even today, on a sunny day, spot prices for electricity are either very low or even negative. The more solar power is available, the lower these prices will be. So your balcony power station is replacing electricity you could get for free anyway. At night, when you are not producing electricity, you still need to buy the expensive electricity from fossil plants.
The reason why personal solar installations are profitable is that you can buy electricity for fixed prices from your local power company. You pay the average of the vastly different low (or negative) prices during the day and the extremely expensive prices on windstill nights. Solar allows you to use your own electricity when the average is below spot prices, and get power for much less when the price you pay is cheaper than spot prices. It's like a state-approved scheme to play the market in the name of decarbonization while actually increasing everybody else's prices and possibly even CO2 emissions.
This is why smart meters are important to providers, they can more accurately model the spot pricing adjustments which means that you actually use LESS fossil fuels. Also most new meter installs support bi-directional metering
There are various good websites for showing the UK generation mix, but pricing seems less public. A lot seems to be done on day-ahead, which is pricing for the whole day not minute by minute. Is there a minute-by-minute ticker? Tariff?
(the reason I'm asking is that I'm skeptical as to how true this is for places that aren't California)
You can see spot prices at the top of grid.iamkate.com for example.
It would be nice to have some belated insight into how the bids look. Like maybe a few random hours released from a week ago?
Oh, and it's half hours. You can't buy or sell five minutes of electricity, just half hours, which is why your smart meter also thinks in half hours. 48 periods per day.
Aha - that led me to https://bmrs.elexon.co.uk/system-prices , which shows that for the last week prices have been hovering in 80-180 range, and there was only one period of negative pricing during the day.
Wow, £100 per MWh and 12% is fossil fuels in the mix at 10:48am ... a bit more Solar adoption and maybe that 12% could go away, it's morning after all.
Which is never, because even then you are still paying some sort of taxes on top of the spot prices and also network fees.
The price of electricity from the network also has to include the price of delivery, while homemade electricity only has to recoup initial investment.
Of course this means given enough home installations (in places with enough sun) the price of electricity from the network will rise, more people will install their own stations, some will even disconnect, rinse and repeat. I read somewhere this exact situation is already playing out already in Pakistan.
To me this illustrates that with renewables (solar and wind) the key is storage. You want to grab all you can during excess production/very low prices periods and then use that for the rest of the day.
You can do exactly that by buying battery packs but (1) they are more expensice pieces of kit than solar panels and (2) capacity and output of DYI/plug in systems is very limited.
A quick check online also says that (in the UK) peak spot prices are usually 7am-10am and 5pm-9pm, which are basically when demand picks up or hasn't dropped yet while solar panels are useless...
> You want to grab all you can during excess production/very low prices periods and then use that for the rest of the day.
Batteries help, but even that is limited in northern countries like the UK. If you look at the data, in July '25, solar produced 2.36 TWh. But in December '25, it was only 0.535 TWh: the output in summer is >4 times the winter output. So either you need to discard 75% of the electricity produced in summer, or you need truly gigantic batteries that store power produced in summer for winter. Both is not economical. Solar is far less efficient in the UK than in, for example, Florida.
In the UK wind contributes more to the grid that solar (not unexpected). Overall the issue with either or both is still that production varies widly over time including within a day.
With solar specifically you have the obvious day/night cycle, which makes storage required to make the most of it.
> I once read an article that in Berlin the sewage system is flushed with fresh water because too many people have installed water saving toilet flushers. So plenty of people bought these water savers and now the price of water has gone up because the water that is directly flushed needs to be paid too.
What is this supposed to mean? You flush less water, therefore water price is more expensive, because flushed water needs to be paid too?
Presumably that the water bill (for tap water) was priced to cover both tap water provisioning and sewage works. But people using (free) rainwater to flush toilets ruined the pricing model, making the tap water price go up.
I honestly don't see the problem, it's probably still worth it (because society still needs to provide less tap water and saves there).
GP is partly right. Most of the cost of sewers is fixed cost: employee salaries, building and maintaining X kilometers of sewers, etc. Some is variable: chemicals, but a small part.
If you, a single person, cut your water usage in half, you pay half as much. But if everybody uses half as much, the system still needs about the same amount of funding. So now you double the per-unit price, and everybody pays the same they were before spending money on water saving features. In this case, even if each person used half as much water, the total water needed isn't cut in half because the sewers need more water to function.
(Also, water isn't "used"; most of it's transported, cleaned, transported, dirtied, cleaned again, transported)
Perhaps that sewers need a certain volume of water flowing in order to function correctly. If that water does not come from toilet flushes, etc then they pump water into them to compensate.
You can spend every euro or dollar only once. If you consider CO2 emissions a critical problem, then you should spend every single dollar as efficiently as possible. Obviously independence of fossil fuels has a value too, as the current situation in the middle east shows.
It would make much more sense to import (renewable) electricity from Spain to Germany than strawberries.
Grids are not set up to move significant percentages of national consumption over longer distances, and expansion is slow, expensive and prone to nimbyism.
Countries already struggle to move electrical energy inside their own borders (e.g. Germany: north=>south), shifting double digit percentages of national consumption across Europe is not gonna happen any time soon. Germany alone plans to spend at least ~€100bn over the next decade on this (internally, not on connecting Spain!).
Much more effective to focus on local generation first than to try and rely on slightly better conditions for solar panels half a continent away.
I have the curse of having an mom who was a smart CPA.
All this stuff root top solar, plug in solar costs at least twice what utility solar. And only makes sense when you have messed up rate setting schemes that enable arbitrage.
But it's not what you want if you want to get the most GW connected as fast as possible.
Like the requirements that new houses have roof top solar. You could get twice as much if you just invested the money in a conventional solar farm.
> But it's not what you want if you want to get the most GW connected as fast as possible.
I agree with rooftop residential solar. The cost per kW is high, each site is fiddly and requires far more labour and paperwork than the extra cost of adding 4kW of solar panels to a large grid scale one.
But plug-in solar bypasses most of that. The cost to the government to allow someone to buy and install a panel on their balcony is effectively nothing. A single 800W panel is not interesting, but the aggregate effect of 10% of households buying an 800W panel at the local shop is an extra 12% of installed solar capacity.
Admittedly that's less than the annual growth rate right now. But it's also almost free.
US costs for rooftop solar (at build time or retrofit) are misleadingly high.
In the EU build time solar roofs overlaps with utility costs but up to 1.5x , and retrofit is say 2x.
To give context. In the EU adding solar to new homes is cost competitive with running existing(!) nuclear plants. In the US only utility scale is competitive with that.
Retrofit rooftop solar is about the same as new nuclear in the US, retrofit is 25% cheaper than new nuclear in the EU.
> Like the requirements that new houses have roof top solar.
As a CPA child, you should understand that the same money is very different when it comes out of a different account.
(everyone watches two critical numbers, income tax and government deficit, so the #1 priority is to hide capital spending somewhere else, in this case by moving it to buyers of new homes)
While true in general, I suspect that this won't change house prices as (I think) those are more driven by supply-demand imbalances rather than the actual costs, and that the increase in costs will go into someone else's profit margin, which may be some mix of the builders (although they're famously opaque from all the sub-contracting) and the land owners.
Regulations like these make the entire renewable energy sector seem like a crazy scam and greenwashing.
They might not have much of an impact on property values (certainly no more than the plethora of existing building regulations). But we shouldn't be surprised if as a result people vote for a candidate whose campaign promise consists of picking up a grenade launcher and blowing up windmills.
On the one hand, it's been obviously economically a good idea to require this for about a decade, both because PV is cheap and would pay for itself even at full price and also because doing it construction time is cheaper than doing it later.
Even moreso now, because PV is now cheaper per square metre than tiles or fences, even if you don't hook it up to the grid afterwards.
On the other hand, this is the UK so maybe. They did Brexit and somehow Farage hasn't been deported for the consequences.
So where are these solar panels that are providing this energy independence being made? In Europe, right?
Because if they were being made in, e.g., China, that wouldn’t really be independence any more than being a trust fund nepo baby makes you a great success.
"We periodically need replacements for our magical energy making machines" is a problem, but it is orders of magnitude less severe than "we will run out of fuel for our furnaces tomorrow."
That said, "running out" of oil isn't necessarily real problem for the US, as we're net exporters of oil. Although the oil we export isn't the same kind as the oil we refine, we could build refineries to refine our own oil and achieve "independence" that way. It'd just be less profitable.
But whether you like China or not, buying their panels and equipment to make yourself energy independent is a reasonable option, especially if (when) their products are good quality and priced well.
Your independence is only at risk if China decides to stop offering you the things you need. In that case, your future supplier will have to change. But not only is that unlikely to happen, it's irrelevant to the NOW. In the NOW, you could be buying tons of what you need to become self-sufficient.
> Once you've bought the panel, unlike oil, that's it. The panel doesn't remember its national origin.
Until there's a geopolitical event occurs and your supply chain gets cut off so any expansion, warranty, or replacement units cannot arrive, so you're stuck at the your current level of deployment (which may or may not be sufficient for your needs).
That is a problem. The only way it could be worse is if your technology required a constant supply of input from a foreign country...
From a geopolitical standpoint running a country on locally produced renewable power is obviously the least risky approach, even if you get cut off from further expansion of your renewable production.
This is normal business. Suppliers change due to all kinds of reasons. If you are planning any major build and you haven't also planned contingency cases, including alternate suppliers, then you are not qualified to be in charge of such a build.
And it's not like you cannot find good alternatives outside of China. They may be more expensive, but they exist (and are high quality - Germany).
Solar panels are piss-cheap to make. They are literally just glass with a transistor on them (huge oversimplification)
All of the materials used are readily available and manufacturing is not incredibly difficult. Inverters and control circuitry is way more of a risk than the panels themselves but there are stockpiles and sources that are good for many places
That's certainly an issue, but much, much less critical than gas.
Are people really suggesting the opposite: that the renewables transition should not occur, and the EU should continue to burn gas from more and more desperate sources, until it can be onshored?
That's nowhere near the level of dependency that fossil fuels bring.
Barring significant damage, you can maintain approximately your current level of power generation for years at a time without more than routine maintenance.
Fossil fuel power requires constant input of, well, fossil fuels.
So while what you're saying is true, it would be a ludicrous stretch to say that it brings solar panels within a few orders of magnitude of fossil fuels in terms of dependency on foreign powers.
Historically panels are generally considered to be exhausted after 30 years of service, although even that means they're down to 80% of their original capacity.
The more failure prone component is the inverter, by a huge margin.
Warranty lives tend to be in the 20+ year range and potential lifespan even higher, so .. kinda?
By coincidence I had my solar panels installed round about the time construction started on Hinkley Point C. They've already paid back their installation cost. I don't expect to replace them any time soon.
Several recent HN posts about "time" and these correlate superbly in relation to the now obvious, to nearly all, global energy issues. Those proactive in a reactive world are often mocked and laughed at until as such passage of time is achieved for those only reactive to learn of the proactive's hindsight choices. For those in the United States aware of the 'behind the scenes' energy grid issues this insight reflects that prices will not be dropping for those electrons we all so depressively require daily just like our air and water. Energy grid decentralization is occurring with the actions of each individual and this article supports exactly that because no one alive can survive in our modern world without those electrons. "Necessity is the mother of invention" only now resonates for some while the futurists here that acted long ago acutely understand this growing trend.
Fairly boilerplate article, but the bit that is news is the UK balcony solar permitting. Better longread: https://solarenergyconcepts.co.uk/post/plug-in-solar-uk/
Government press release with a long list of pull quotes: https://www.gov.uk/government/news/government-to-make-plug-i...
(I note that in the alternate universe where Ed Miliband became PM because he didn't eat a bacon sandwich, we could have had this a decade ago. It is embarrassing to be beaten on environmentalist regulatory efficiency by Germany)
British industry and standards bodies think this is an unsafe plan.
Of course they would because it's work being taken away from them but it would be allowing people to plug generators into ring finals with unidirectional breakers. It's not even guaranteed that the circuit is protected by anything newer than fuse wire or an MCB. No guaranteed earth leakage detection. No guaranteed surge protection. Relying on the cheapest inverters to sync frequency accurately. And
I have more faith in German standards and work ethic than our own.
I find it interesting because often the best way to achieve a safe building code is to learn by allowing with basic guard rails and iterating as things happen. This isn’t ideal for the rare individual impacted by the “things happening,” but collectively we refine and iterate. Our current standards weren’t arrived at by navel gazing - we got the codes we have by experience. It’s hard to realize that from the present that you can’t reasonably learn without doing and by constraining without learning prevents growth and learning.
Are there lessons on safety that need to be learned here? We already know what the happy path looks like, and we've plenty of lessons on what the unhappy path will look like.
It isn't as if electric charge coming from balcony solar panels is some new magical-seeming type of electricity.
Safety is statistical and depends on human behavior. Unexpected behaviors might appear. For example some places require a power outlet on kitchen islands because with out, people will use cords to the wall which creates tripping hazards.
Also, why do wires have to be fixed to joists every 300 mm? It's not about the electrons.
“Unidirectional breakers” aren’t a thing for AC circuits.
https://www.bgelectrical.uk/uk/circuit-protection/devices/rc... Right there, both bidirectional and unidirectional breakers.
The situation in germany is essentially the same, but that's why net supply by these is limited to 800 W. I don't think anything changes w.r.t. earth leakage, why would the presence of the solar supply change anything from the RCD and fault point of views, respectively?
Not expert but one difference is that in Germany the standard wiring is radial circuits with 16A MCBs while in the UK it's ring wiring with 32A MCBs.
So in the UK we have 2.5mm^2 wires in a ring on a 32A MCBs... Of course a 2.5mm^2 wire is rated ~20A so any issues with the ring (sockets still work since connected from the other branch) can burn the wire before the MCB trips...
The "standard" wiring is 1.5mm² on 16A MCBs which are rated to trip at 1.13-1.45x nominal current (so 18-23 A). So this is already mildly improper because you can pull elevated currents continuously and dramatically shorten the life of the insulation.
He also removed the effective ban on onshore wind construction that was introduced a month after he lost the election, restarting after a decade of lost opportunity.
This Trump-level idiocy that is just never mentioned, even as people blame the gas burned in england on windy days as a cost of wind curtailment, when the curtailment is more a like a third of the cost. Burning gas to power people who chose not to build turbines is the other 2/3rds.
In the alternate world that is tens of billions of gas costs avoided to date and tens of billions more in future.
At the same time they are banning wind turbines leaders (Chinese companies) from opening factories in the UK... [1][2]
[1] https://www.bbc.co.uk/news/articles/c995xjxk97mo
[2] https://www.energyvoice.com/insights/energy-opinion/594763/m...
That seems rather dumb. I wonder why they blocked the Ming Yang thing in Scotland? The UK seems to make quite a lot of dumb energy decisions like blocking UK North Sea gas and then buying North Sea gas from Norway.
Yes it is rather 'dumb'. Apparently the policy is to reset relations with the EU so perhaps selling out to Siemens is deemed preferable, or perhaps they got the usual friendly phone call from Washington D.C, it is difficult to follow. And that's the point: Where is the plan? Where is strategic thinking?
> I note that in the alternate universe where Ed Miliband became PM because he didn't eat a bacon sandwich, we could have had this a decade ago
I read what is happening in exactly the opposite way. To me it shows that Milliand and the government at large do very little with no strategic thinking and no plan (same as the guys before in fairness but this government was supposed to be soo different...) and, in this case, is only reacting in a panic after almost 2 years in office to the pressure of "doing something" because of the Iran war, while also being told (slight mitigating circumstances for Milliband) that it mustn't cost anything. I always picture scenes from The Thick of It/ In the Loop when I imagine how they come up with 'ideas'.
These policies were in their manifesto, they just take some time to enact, even with a majority government.
Distributed energy production / storage is the key for resiliency in the future.
Every solar farm doesn't need to be China Size - it doesn't even need to be a "farm", just put them on roofs.
And don't let perfect be the enemy of good. Yes there are times when solar doesn't produce energy, but there are also times where it OVERproduces.
Wild that you're getting downvoted for saying something so obvious. Weird.
Not weird if you’ve been participating in discussions on clean energy since the beginning of this century.
The inevitability of the energy transition has been obvious for so long, and even when it’s done there will be cranks insisting that it’ll never work.
That's the same kind of problem solving that thought making self driving Teslas is the solution for infrastructure problems.
I'm fairly certain securing one's household's access to energy independent of rate increases triggered by a combination of aging infrastructure and data center power demand doesn't have a lot in common with tech bros attempts at reinventing trains badly from first principles but I'm open to hear the argument. Care to unpack that?
Politics of solar, at work
> And don't let perfect be the enemy of good. Yes there are times when solar doesn't produce energy, but there are also times where it OVERproduces.
When solar OVERproduces you have to literally pay someone to consume that energy, most probably wind farms, which could be producing energy instead. So you pay actually twice. When the solar underproduces, you need to bring in alternative sources, but those now have to cover all their fixed costs and generate return on investment over this limited timeframe, which means the actual backup prices hit stratospheric levels.
What's the actual cost of solar with actual net-billing?
Home installations just cut it off. In both of these cases.
I did my own battery backed installation. When I'm underproducing I can shed load (I turn off my AC - almost always that's enough, and it's automated by relay). When I'm overproducing (ex - my battery is full and my load is still not enough to consume input) I just don't let the panels generate more current than I can consume.
Managing grid scale power is different concern, and not particularly relevant to small household generation. Especially not relevant in the 800W category for "balcony solar" (which is much smaller than what I'm working with).
Solar is fucking coming, whether you continue to shove head into the ground or not.
It's just way more affordable. Getting easily more affordable as batteries continue to improve.
I honestly doubt I'll still be connected to a local utility grid for electric 10 years from now, and I live in a region of the US that has considerably cheaper grid power than most areas.
My current EV has a 38kW battery.
When it's too worn out for car use (SoH around 60-70%), it's still perfectly enough to run _everything_ in my house for multiple days - except for the electric sauna, and I'm smart enough to turn it on if there are production issues :D
There's a reason why EV's will never be as cheap as the cheapest ICE shitbox. Just the bare metals in the battery are worth thousands when recycled, even more if the battery is still viable.
If you ever are looking to implement that EV battery as house backup, this repo might be useful: https://github.com/dalathegreat/Battery-Emulator
I did mine with it and old leaf 24kwh battery (~60k km). After all the safety margins I get ~15 kwh out of the battery.
This is not how curtailment works.
Curtailment is when an energy company has successfully bid on delivering electricity for the next block of time (an hour, for example) but it can’t provide that agreed amount of power because it would overload the grid. There are various reasons why that would happen: faults and unexpected lack of demand, for example. In that case the company is paid for the energy it was contracted to deliver, only for that period of time, even though it did not provide power.
It is wrong to say that overproducers HAVE to be paid. They don’t. They only have to be paid if there was an agreement to buy that power but for whatever reason the grid can’t take it. Normally if there is a generation surplus, the cheapest companies will win the bid to provide power and the others will simply not be paid.
Here in Finland electricity prices can drop to under 1c/kWh due to renewables, basically every time it's sunny and/or windy electricity is practically free (the transfer costs are static though).
A few times the price has actually been negative, people got paid for using electricity due to overproduction =)
There will be connected batteries in every home solving this problem faster than the fossil fuel lobby can come up with a new talking point about why it’ll never work.
> When solar OVERproduces you have to literally pay someone to consume that energy,
Can't we just throttle the solar panel? In a worst case, you just pull the plug. It's not like a nuclear power plant which needs to be shut down carefully, or am I misunderstanding something?
Yes that's exactly how it works, it's called curtailment.
You can limit amount you feed back into network.
Not sure how is situation with home installations, factory i work for runs 150kw plant for our own consumption and don't bother with selling, but i know that we can set up how much we want/are allowed to feed back.
>you have to literally pay someone to consume that energy,
Here's the thing. That's a rule and not a technical problem. Absolutely no reason to do this other than rules and regulations.
Yes, but even more so, it's a good sensible rule!
People don't even bother to argue why it's bad, they've just seen so many headlines telling them it's bad they don't question it.
I'll question it. Why does it exist? Why can't we just shut off the panels or dump excess energy into a metal rod? Why do we need to have a buyer at all?
It's not a buyer, people are paid to take the energy that would otherwise be wasted. And when energy use is shifted it means you need to generate less later, saving money.
The people who pay that cost to the people using the energy are people running energy generators that suffer wear and tear when they ramp down.
Or sometimes it's a subsidy for the use of clean energy being passed on to ensure the clean energy is actually used, not wasted.
All upside, no problems at all.
Because otherwise the incentive structures for solar-as-baseload, sweeping the actual cost on the consumers, collapse. The system is built on putting equality sign between oversubscribed solar and coal/gas backups during times of undersubscription.
> When solar OVERproduces you have to literally pay someone to consume that energy, most probably wind farms, which could be producing energy instead.
You don't have to do this with solar, you can just disconnect the panel and have it go a bit hotter. For producers that have a long-ish bringup time, yes, you might need to do this at time.
The situation is slightly complicated by dispatch order, and domestic solar isn't usually dispatchable at all. Grid-scale farms are.
Wind farms don't consume energy, but there is a real issue with how often they have to be "curtailed" (paid to turn off). That is to a great extent due to issues with grid connectivity between Scotland and the rest of the UK, which are (slowly) being worked on.
Wind curtailment is the deliberate reduction of electricity output from wind turbines, despite their capability to generate power under existing wind conditions. This practice is typically implemented by grid operators to maintain the stability of the electrical grid or to address specific operational constraints.
https://www.enlitia.com/resources-blog-post/what-is-wind-cur...
"paid to turn off" Wind energy providers in some countries are compensated for curtailment, this a form of subsidy for renewables. It can be payed directly by the goverment, or it is added to the price of electricity for consumer.
https://www.cleanenergywire.org/news/renewable-curtailment-c...
My understanding is that all inverters sold at this moment, in the EU, need to have demand response and grid curtailment mechanisms by law.
Cheap home solar installations usually have a disconnect- do they not use those in larger scale installs?
I'm also surprised they aren't using batteries to capture overproduction. They've been clutch in the US, and we're not exactly pushing the envelope of green energy nowadays
When there's an OVERproduction of energy, that really means there's an UNDER-availability of storage. Battery tech continues it's march towards cheaper prices, and alternatives such as thermal storage are making inroads as well.
It borders on criminal to have abundant energy production be disservice.
I'm no energy markets analyst, so take this with a grain of salt, but I think the next major breakthrough for solar (not the slow, inevitable rollout we're seeing now) will be when somebody figures out an economical way export this periodic overproduction. There is basically never a time when humanity as a whole has an overproduction of free energy, but at present we also don't have a way to make money turning this surplus into a tradable product (like oil, coal, LNG, etc.) because all the electric-powered processes for making such products (ammonia, methane, primary aluminum production, etc) require big hunks of capital equipment that lose money unless they're operated more or less continuously. Battery, thermal, pumped hydro, etc. help here, in that enough of it can theoretically turn off-and-on solar/wind power into a continuous load to power your aluminum smelter or whatever.
Even better though, would be a cheap electrically operated methane plant that you could afford to run intermittently. This, plus a peaker natgas generating plant make, effectively, a battery of infinite size, or you can sell it to any of the many eager buyers of natgas.
Building a small, prefab, plant like this, if possible, would seem to be mainly a problem of scale, and therefore it seems likely that China will get to it pretty soon.
No you don’t, you could just ground it. Paying them is a choice.
Inverters can be configured with export limits to limit, or entirely halt, energy exports based on market or grid signals. Term of art is "curtailment."
https://en.wikipedia.org/wiki/Curtailment_(electricity)
"If you find dollar bills on the ground you need to pay someone to collect it as litter"
Charge batteries, do electrolysis, or a multitude of other uses (I know some companies do that already)
This is literally the only sane usage for hydrogen outside of industrial uses, when you have a massive excess of renewables, use it to turn water into pressurised hydrogen.
And when the prices go up, you run that through a grid scale fuel cell and feed it back to the network.
Used 240w modules built in 2010-2012 are worth $60-100 CAD at the moment in small quantities. There will be hundreds of thousands hitting the market (as long as they didn't hit the ground with careless removals) in ~2030+ as microFIT contracts in Ontario expire.
There is no clear path to switching these arrays to Net Metering, as of yet. Prepare for all sorts of unrecycled solar panels and potential loss of renewable capacity that is already installed.
Net metering is really, really smart when the installed base is small relative to the fossil fuel power plant capacity. But it doesn't scale forever. Once it gets up towards 20-40% of the fossil fuel capacity, it goes from an asset to a liability.
Suppose I have a 100MW gas turbine. And suppose there's 1MW of solar installed in my generation network. I don't really care if I sell 80MW at noon and 90MW around dinner time and 50MW through the night, or if instead it's 79MW at noon and 91MW at dinner and 51MW at night. The gas costs about the same irrespective of when I burn it so a bit of a fuel shift doesn't really matter.
But take that 1MW and turn it into 20MW and suddenly we go from 80MW at noon to 60MW at noon, 90MW at dinner to 110MW at dinner and uh oh. You see the problem? Whatever losses I endured at noon I don't get to make up for at dinner because my plant only goes up to 100MW and now we're not just shifting when we burn how much fuel, we're literally having to shift the power generation to a different plant.
Is this example precisely accurate? Absolutely not. But it helps you get a feel for the problem of net metering at scale. The grid can act as a battery for a few % of total generation, but by the time you hit some number, maybe 20% maybe 40% net metering turns from a cool math trick to a real cost on the grid.
Net metering only makes sense as a way to incentivize solar installations. Looking at the economics, it's not something any utility would offer willingly.
It's like if the grocery store let you give them milk for a credit at full price. (Let's ignore the sanitary/health/quality issues that would come up.) You decide to buy a cow and you drink that milk. Sometimes you need more than your cow can give so you buy extra from the store. Sometimes you need less and you sell the extra to the store. Long term, you use as much as your cow produces on average, so you pay the store nothing. But the store has provided a valuable services to you and has incurred expenses in doing so. They have to keep the lights on and maintain a building and pay workers to handle your transactions but they make no money from you. The only way it would work at all is if they made enough money from their non-cow-owning customers to make up for it, and that can only take you so far.
Could you elaborate on this? Why would people remove a working solar system?
Buildings get torn down. Roof needs a replacement and the owner doesn't feel like it is worthwhile to redo the solar install for panels that only have 5 years of warranty left, or maybe they want to replace them with higher power models with a fresh warranty. There are any number of reasons why someone might need to offload otherwise functional solar panels.
Currently used solar panels are a hot commodity, with many groups selling them by the pallet, because 10 year old solar panels are still efficient enough to easily pay for themselves. Very few installations will care about specifically how many panels they want, they just want a nameplate output per dollar figure.
Old inverters might not have a second life though.
Related, there's also a boom in at-home battery installations.
https://www.swissinfo.ch/eng/climate-adaptation/switzerland-...
The UK previously didn't allow small plug in solar panels (the kind that you just plug in to a mains socket) due to, I believe, safety reasons. This has changed within the last few days https://energysavingtrust.org.uk/solar-roadmap/
I believe it’s only legal in Utah so far in the US: they legislated it last year, and apparently half the country is expected to pass a copy-paste version in their next sessions
Current state by state status (not my site): https://pluginsolarusa.com
It hasn't changed... yet. The media noise is because the government has announced that they were reviewing current rules with the aim of allowing "balcony solar" by the end of the year.
For european individuals, yes. For european nations, not in the least. They try to avoid independent consumers and producers of energy with all the regulations they can throw to them.
A quick check of OBI (our main home-improvement chain) shows that I can get that 800w "balcony" plug-and-go system for 300-600 EUR depending on the exact panels and inverter I want, and it's all pre-approved. I have fill in a simple, free form online announcing that I've done so or am planning to, and I'm now technically an energy seller - my local utility pays some for power fed back into the network (not nearly the rate they charge for delivering power, but better than a poke in the eye with a sharp stick). If I don't want to accept 0.08 EUR/kWH, I'm free to plug in a battery for any excess. Our base load when I have my work computer and monitor on during the day is somewhere in the neighborhood of 300w, so I think this would work out well for us. I need to get off my bum and do it.
Shockingly unbureaucratic for Germany.
There is, as one could imagine, somewhat more burden for larger systems that require the involvement of someone who is actually an electrician, but I don't want my neighbors to be able to DIY fire hazards.
What nations are you talking about? E.g. in Germany, you can buy up to 7kW of panels, screw them onto your roof, wire them up with controller and battery and feed up to 800W into local grid, no one is gonna stop you or anything (only thing you need to do is register online with the grid operator if you have >2kW of panels).
Legislation is, in fact, specifically made so people (i.e. landlord) actually can't easily stop you from doing this.
Can anybody explain how these plug-in solar panels work? I am suprised that it's possible to just plug them in to your wall socket.
For instance, isn't it complicated to have their output be in perfect sync with the frequency that comes in via the electricity net? Because to me it seems that if they won't, you will have lower benefits or even a net minus after plugging it in.
> isn't it complicated to have their output be in perfect sync with the frequency
Not especially, given that the inverter has a microprocessor in it. All it has to do is measure the phase of the existing grid.
I don't have references for how it's actually done, but one obvious approach is simply to wait at each zero-crossing for a new half-cycle to cross a voltage threshold before turning on the output. This also implements the requirement to drop out if the grid goes away. It is probably also possible to measure during the "off" side of inverter output PWM, in the same way that variable frequency motor drivers work.
I guess if you can solve phase alignment then another big problem is grid capability?
If everyone plugged one in, could the transmission network reliably deliver the power generated where it's needed? I thought that was a serious long term challenge for utilities wrt solar.
Not a specialist, just from what I heard: There are two things that make it work. First they are not really "independent" like the title says. They sync with the grid frequency. If the grid is down they shut off for safety. The other reason it works is that the grid power inside the home is just what you get as incoming power 〜230V. For example, I think in the US you get 240V or so delivered to your house, but 120V from the plug.
Typically, you have "dumb" panels connected to a mppt-controller/charger/inverter box which is connected to batteries and and electrical plug. This controller tunes voltage/current that is taken from the panels, optionally manages the attached battery and measures and feeds into the grid connection.
Some systems are capable of running in isolation from grid (providing 230V AC on their own), but this is less common and often unnecessary.
My understanding is that plug-in solar inverters do sense what is coming from the grid and phase-sync to it with a PLL, and also adjust voltage accordingly.
They are going to start selling solar panels at Lidl, a German-owned grocery store chain https://www.independent.co.uk/extras/indybest/house-garden/l...
to answer the first question in the article
"Many consumers want to know how long it will take them to make back the upfront costs of solar"
my answer is that the payback is imediate, right from the first moment watching as energy is generated out of thin air, and the sudden relief from getting off the energy angst missery-go-round, and the sheer borring inertness of solar pv as it does the thing with zero detectable effort, is gratifying and relaxing in a way that money never gives.
I will add that solar pv is increadably robust, and damage tollerant as well, you can drive a claw hammer through a panel, and while it does not improve the performance, the degradation is actualy not that much, and it will continue to function for years
It’s already possible for consumers to know that, I worked on the software that powers the tools that tell US consumers this at Genability ca 2015.
As far as I know, they never cracked the European market, so if you’re interested in working on that, I’m currently available for hire! Info in profile :)
We just got solar panels and a battery installed on our house. I try to be hard-headed about the economics when planning, but I have to say the _experience_ of having done it is exactly as you describe.
The other thing it made me is angry at the political morass that these things seem to be in.
At a technical level I understand the ‘base load’ arguments, but we are throwing away _so much energy_ that’s just there for the taking by not having these everywhere. On most days, our house (in Western North Carolina) gets enough energy from the sun that we net-export to the grid - and we have an EV! There’s just no need for the massive amounts of carbon we are spewing into the air - the energy is just falling onto us!
In the future, providing we’re still around, we’ll look back at a time when we could’ve been getting all our energy needs from just the sun (and wind etc.) and shake our heads in disbelief at those who fought against the idea that we should even think about efficiently using it so viscerally.
The mindset shift towards “how many hours of computer usage did that one panel enable” is like the mindset shift from learning calculus, in some ways. Not quite a paradigm shift, but you gain a new appreciation for conservation of use when it’s a difference between choice of $/kW/hr and “wow, the panel powered that for most of the day”.
At the same time, many people will just use a solar calculator or watch or yard lights etc, oblivious to it all.
Show people a solar powered laptop, a solar powered phone, or a solar powered tablet, then they will be impressed.
Remember the craze about solar powered car competitions?
permacompute + solar would make for quite the $100 laptop competition.
Is it immediate? Sure, there is satisfaction that you are using 'free' electricity. But it does have an upfront cost. I calculated that it would take over 11 years to recoup the investment based on our current usage. Given we already get cheap night-time rates to charge the car and run appliances, it is hard to justify.
Like many UK houses, we have gas central heating too. I guess if we had a battery too (more investment) then we could switch to using electric oil-filled radiators, though they would not heat the whole house. And we could install a hot water tank.
I guess for new builds there is a real opportunity, but for an existing household I'm struggling to see how it works - and I want it to!
I don't think it ever makes sense to switch to electric radiators. It might make sense to switch to a heatpump, but you need to avoid being hugely overcharged by the installers and there are flow issues if you have 8mm piping.
This ROI calculator looks reasonable: https://ukcalculator.com/solar-panel-roi-calculator.html - note that it subtracts the install cost for you, so any case where the final figure is positive is profitable. But of course that depends on whether grid prices go up or down in the next decade ...
Well France did move to electric everything (cooking, hot water, heating) in the past thanks to ample nuclear electricity production (and possibly not too harsh winters). Unfortunately they let their nuclear programme decay and are struggling now (EU grid integration does not help)...
I think a big part of the push to install heat pumps now is that it is understood that electricity production is in dire straights, taking into account that the transition to EV requires a lot of electricity.
Are you talking about rooftop solar?
For an 800W balcony system your background house usage is likely to be enough to self consume most of it.
You'd wouldn't be able to run even a small oil heater except maybe in peak summer.
It's a good match for working from home as it's a small amount of power spread over daylight hours.
>> "Many consumers want to know how long it will take them to make back the upfront costs of solar"
> my answer is that the payback is imediate,
So if I pay $35k for an install, I get a $35k check the first time I connect it to the grid? Pretty sure it doesn't work that way. But it would be a nice subsidy from the government if they were really motivated.
I guess you're saying you start to feel good and validated to have spent the money by seeing _some_ savings every billing period. It's hard to argue with feelings of course, but that's not not the original concern. People want to know how long is it going to take: 1, 5, 10 years or ... never (if panels degrade or break before it will never pay off) to pay off their investment.
"Suddenly" is horrific evidence that the government has no idea how to do long-term plans.
Wait until you tell them you can run cars entirely on electricity from a solar farming. I'm sure they will ignore you until the price of diesel reaches four-digit territory. 1000p today? If only we didn't have to pay these incredible prices, what a miracle that would be..
It's not that government has no idea, it's that around the world, too many "leaders" are directly or strongly indirectly being enriched by the fossil fuel industry and their support industries.
So politicians have a choice: do what's right for the people, or gain more power/money for themselves. Not every one of them chooses poorly, but enough do that it is difficult for real progress to be made.
Don't forget the truly staggering amount of voters who seem to be ideologically opposed to energy independence and self delusion to support those bought politicians.
People earnestly and genuinely spout "But the birds" to wind installations. Why are they so intent on taking any possible excuse? Why do they need to have an opinion on something they know nothing about?
A shame local companies where I am from have year long backlogs.
The "balcony solar" system is going to be available in Lidl for no-approval self-install. Limited to 800W.
Depends on your locality. The Fossil fuel industry is lobbying hard against this and is successful in some places.
I once read an article that in Berlin the sewage system is flushed with fresh water because too many people have installed water saving toilet flushers. So plenty of people bought these water savers and now the price of water has gone up because the water that is directly flushed needs to be paid too.
The 'balcony power stations' are the same thing. They get subsidised, and you even get a fixed kWh price when pushing into the grid.
The problem is that in the end it will become more expensive for everybody because at times you have a surplus driving the whole sale electricity prices into the negative while still paying fixed prices for injection into the grid.
To make this economically viable, you have to have everyone paying spot prices. Everything else is just green ideology driven inefficiency.
Just to make it clear, I think renewables are an important option for the future. But to make them a viable option of the electricity energy mix, supply and demand, storage and grid capacity need to be taken into account.
Last not least, there is plenty of low hanging fruit to drive CO2 emissions down: drive up the truck tolls. Currently you have potatoes farmed in Germany, driven to Poland to get washed, transported to Italy to be converted to french fries and transferred back to Germany into the super markets.
Same goes for home office, during Covid it was possible for many workers to continue with their work. Does an accountant need to drive to an office every day? Nope. How many business trips could be replaced by a video call?
If the CO2 emissions problem is to be solved rather sooner than later, the money has to be spend efficiently as there isn't enough of it.
The price of water has gone up for a multitude of factors. One of them is water savings in general, but not primarily because the sewage system requires regular flushes. The reason is that water gets paid per qubic meter and includes a fresh water and a waster water component. The assumption is that almost all fresh water you use ends up as waste water. Now, the grid has a very substantial fixed-price component that's largely independent from the actual current volume being used. Putting pipes in the ground and maintaining them there is an actual costly endeavour. If water use now drops, and the baseline cost remains stable, then it's entirely expected that the price per volume rises. It's simple math. The same baseline cost needs to be brought in via less volume.
This will also happen to people that use residential gas. As less and less people use residential gas, the maintenance of the gas network gets distributed among less and less customers.
> The 'balcony power stations' are the same thing. They get subsidised, and you even get a fixed kWh price when pushing into the grid.
They are subsidized on purchase, but the price they get when pushing energy into the grid is by default fixed at 0. The network accepts the power, but there's no payment. It's also capped at 800W delivery, meaning that at peak power generation, you'd earn a whopping 5 cent an hour with the current subsidy for full scale solar power. So in practice, the only benefit owners have is that they draw less power from the net which is much more attractive because of the pricing structure. You can, optionally, register your balcony power station as a regular solar power plant, but then you're subject to a whole bunch of rules and regulations (for example you need a suitable elctricity meter etc.). This option is generally not attractive for such small power generations.
Fundamentally, though, the same issue as with the water and gas network exists with all localized (solar) power generation. If more and more people use the grid only as a backup, or for winter energy needs, then the overhead of maintaining the grid will have a larger cost contribution to the total cost of electricity.
As soon as everybody is paying spot prices, balcony power stations are not economically viable anymore. Even today, on a sunny day, spot prices for electricity are either very low or even negative. The more solar power is available, the lower these prices will be. So your balcony power station is replacing electricity you could get for free anyway. At night, when you are not producing electricity, you still need to buy the expensive electricity from fossil plants.
The reason why personal solar installations are profitable is that you can buy electricity for fixed prices from your local power company. You pay the average of the vastly different low (or negative) prices during the day and the extremely expensive prices on windstill nights. Solar allows you to use your own electricity when the average is below spot prices, and get power for much less when the price you pay is cheaper than spot prices. It's like a state-approved scheme to play the market in the name of decarbonization while actually increasing everybody else's prices and possibly even CO2 emissions.
This is why smart meters are important to providers, they can more accurately model the spot pricing adjustments which means that you actually use LESS fossil fuels. Also most new meter installs support bi-directional metering
> spot prices for electricity
There are various good websites for showing the UK generation mix, but pricing seems less public. A lot seems to be done on day-ahead, which is pricing for the whole day not minute by minute. Is there a minute-by-minute ticker? Tariff?
(the reason I'm asking is that I'm skeptical as to how true this is for places that aren't California)
You can see spot prices at the top of grid.iamkate.com for example.
It would be nice to have some belated insight into how the bids look. Like maybe a few random hours released from a week ago?
Oh, and it's half hours. You can't buy or sell five minutes of electricity, just half hours, which is why your smart meter also thinks in half hours. 48 periods per day.
Aha - that led me to https://bmrs.elexon.co.uk/system-prices , which shows that for the last week prices have been hovering in 80-180 range, and there was only one period of negative pricing during the day.
Wow, £100 per MWh and 12% is fossil fuels in the mix at 10:48am ... a bit more Solar adoption and maybe that 12% could go away, it's morning after all.
It's windy (41% wind). Solar is not great all day long and all year long in the UK (8% solar at the moment, it is a cloudy day).
> As soon as everybody is paying spot prices
Which is never, because even then you are still paying some sort of taxes on top of the spot prices and also network fees.
The price of electricity from the network also has to include the price of delivery, while homemade electricity only has to recoup initial investment.
Of course this means given enough home installations (in places with enough sun) the price of electricity from the network will rise, more people will install their own stations, some will even disconnect, rinse and repeat. I read somewhere this exact situation is already playing out already in Pakistan.
To me this illustrates that with renewables (solar and wind) the key is storage. You want to grab all you can during excess production/very low prices periods and then use that for the rest of the day.
You can do exactly that by buying battery packs but (1) they are more expensice pieces of kit than solar panels and (2) capacity and output of DYI/plug in systems is very limited.
A quick check online also says that (in the UK) peak spot prices are usually 7am-10am and 5pm-9pm, which are basically when demand picks up or hasn't dropped yet while solar panels are useless...
> You want to grab all you can during excess production/very low prices periods and then use that for the rest of the day.
Batteries help, but even that is limited in northern countries like the UK. If you look at the data, in July '25, solar produced 2.36 TWh. But in December '25, it was only 0.535 TWh: the output in summer is >4 times the winter output. So either you need to discard 75% of the electricity produced in summer, or you need truly gigantic batteries that store power produced in summer for winter. Both is not economical. Solar is far less efficient in the UK than in, for example, Florida.
In the UK wind contributes more to the grid that solar (not unexpected). Overall the issue with either or both is still that production varies widly over time including within a day.
With solar specifically you have the obvious day/night cycle, which makes storage required to make the most of it.
> They get subsidised, and you even get a fixed kWh price when pushing into the grid
Neither of these is going to be true for the UK balcony scheme (you can't get export generation pricing unless it's an MCS-certified install).
> drive up the truck tolls.
The price of diesel is going to do this anyway very soon.
> I once read an article that in Berlin the sewage system is flushed with fresh water because too many people have installed water saving toilet flushers. So plenty of people bought these water savers and now the price of water has gone up because the water that is directly flushed needs to be paid too.
What is this supposed to mean? You flush less water, therefore water price is more expensive, because flushed water needs to be paid too?
Presumably that the water bill (for tap water) was priced to cover both tap water provisioning and sewage works. But people using (free) rainwater to flush toilets ruined the pricing model, making the tap water price go up.
I honestly don't see the problem, it's probably still worth it (because society still needs to provide less tap water and saves there).
GP is partly right. Most of the cost of sewers is fixed cost: employee salaries, building and maintaining X kilometers of sewers, etc. Some is variable: chemicals, but a small part.
If you, a single person, cut your water usage in half, you pay half as much. But if everybody uses half as much, the system still needs about the same amount of funding. So now you double the per-unit price, and everybody pays the same they were before spending money on water saving features. In this case, even if each person used half as much water, the total water needed isn't cut in half because the sewers need more water to function.
(Also, water isn't "used"; most of it's transported, cleaned, transported, dirtied, cleaned again, transported)
Perhaps that sewers need a certain volume of water flowing in order to function correctly. If that water does not come from toilet flushes, etc then they pump water into them to compensate.
The conclusion that saving water is greenwashing is just wrong.
> This is just made up.
Or not. https://www.welt.de/wirtschaft/article152318777/Wassersparen...
Edit: parent changed his answer, I have included it now.
Thinking of this in terms of markets is the real ideologically driven inefficiency.
You can spend every euro or dollar only once. If you consider CO2 emissions a critical problem, then you should spend every single dollar as efficiently as possible. Obviously independence of fossil fuels has a value too, as the current situation in the middle east shows.
It would make much more sense to import (renewable) electricity from Spain to Germany than strawberries.
No this would not make more sense.
Grids are not set up to move significant percentages of national consumption over longer distances, and expansion is slow, expensive and prone to nimbyism.
Countries already struggle to move electrical energy inside their own borders (e.g. Germany: north=>south), shifting double digit percentages of national consumption across Europe is not gonna happen any time soon. Germany alone plans to spend at least ~€100bn over the next decade on this (internally, not on connecting Spain!).
Much more effective to focus on local generation first than to try and rely on slightly better conditions for solar panels half a continent away.
You shouldn't be spending euros or dollars at all. The economic system is the ideology holding us back.
So...what should we be spending?
Gold coins? Pesos? Cows? Inferior-quality copper ingots?
It's entirely possible that you have a good point, but if so, it's gonna need a whole hell of a lot more context to elucidate.
I have the curse of having an mom who was a smart CPA.
All this stuff root top solar, plug in solar costs at least twice what utility solar. And only makes sense when you have messed up rate setting schemes that enable arbitrage.
But it's not what you want if you want to get the most GW connected as fast as possible.
Like the requirements that new houses have roof top solar. You could get twice as much if you just invested the money in a conventional solar farm.
> But it's not what you want if you want to get the most GW connected as fast as possible.
I agree with rooftop residential solar. The cost per kW is high, each site is fiddly and requires far more labour and paperwork than the extra cost of adding 4kW of solar panels to a large grid scale one.
But plug-in solar bypasses most of that. The cost to the government to allow someone to buy and install a panel on their balcony is effectively nothing. A single 800W panel is not interesting, but the aggregate effect of 10% of households buying an 800W panel at the local shop is an extra 12% of installed solar capacity.
Admittedly that's less than the annual growth rate right now. But it's also almost free.
US costs for rooftop solar (at build time or retrofit) are misleadingly high.
In the EU build time solar roofs overlaps with utility costs but up to 1.5x , and retrofit is say 2x.
To give context. In the EU adding solar to new homes is cost competitive with running existing(!) nuclear plants. In the US only utility scale is competitive with that.
Retrofit rooftop solar is about the same as new nuclear in the US, retrofit is 25% cheaper than new nuclear in the EU.
> Like the requirements that new houses have roof top solar.
As a CPA child, you should understand that the same money is very different when it comes out of a different account.
(everyone watches two critical numbers, income tax and government deficit, so the #1 priority is to hide capital spending somewhere else, in this case by moving it to buyers of new homes)
While true in general, I suspect that this won't change house prices as (I think) those are more driven by supply-demand imbalances rather than the actual costs, and that the increase in costs will go into someone else's profit margin, which may be some mix of the builders (although they're famously opaque from all the sub-contracting) and the land owners.
Regulations like these make the entire renewable energy sector seem like a crazy scam and greenwashing.
They might not have much of an impact on property values (certainly no more than the plethora of existing building regulations). But we shouldn't be surprised if as a result people vote for a candidate whose campaign promise consists of picking up a grenade launcher and blowing up windmills.
On the one hand, it's been obviously economically a good idea to require this for about a decade, both because PV is cheap and would pay for itself even at full price and also because doing it construction time is cheaper than doing it later.
Even moreso now, because PV is now cheaper per square metre than tiles or fences, even if you don't hook it up to the grid afterwards.
On the other hand, this is the UK so maybe. They did Brexit and somehow Farage hasn't been deported for the consequences.
So where are these solar panels that are providing this energy independence being made? In Europe, right?
Because if they were being made in, e.g., China, that wouldn’t really be independence any more than being a trust fund nepo baby makes you a great success.
"We periodically need replacements for our magical energy making machines" is a problem, but it is orders of magnitude less severe than "we will run out of fuel for our furnaces tomorrow."
That said, "running out" of oil isn't necessarily real problem for the US, as we're net exporters of oil. Although the oil we export isn't the same kind as the oil we refine, we could build refineries to refine our own oil and achieve "independence" that way. It'd just be less profitable.
> In Europe, right?
Germany makes a lot of high quality solar panels.
But whether you like China or not, buying their panels and equipment to make yourself energy independent is a reasonable option, especially if (when) their products are good quality and priced well.
Your independence is only at risk if China decides to stop offering you the things you need. In that case, your future supplier will have to change. But not only is that unlikely to happen, it's irrelevant to the NOW. In the NOW, you could be buying tons of what you need to become self-sufficient.
Countries other than China make panels too. India is dealing with an oversupply from domestic production right now: https://solarmagazine.com/2025/08/india-solar-supply-chain-f...
Once you've bought the panel, unlike oil, that's it. The panel doesn't remember its national origin.
> Once you've bought the panel, unlike oil, that's it. The panel doesn't remember its national origin.
Until there's a geopolitical event occurs and your supply chain gets cut off so any expansion, warranty, or replacement units cannot arrive, so you're stuck at the your current level of deployment (which may or may not be sufficient for your needs).
That is a problem. The only way it could be worse is if your technology required a constant supply of input from a foreign country...
From a geopolitical standpoint running a country on locally produced renewable power is obviously the least risky approach, even if you get cut off from further expansion of your renewable production.
This is normal business. Suppliers change due to all kinds of reasons. If you are planning any major build and you haven't also planned contingency cases, including alternate suppliers, then you are not qualified to be in charge of such a build.
And it's not like you cannot find good alternatives outside of China. They may be more expensive, but they exist (and are high quality - Germany).
Solar panels are piss-cheap to make. They are literally just glass with a transistor on them (huge oversimplification)
All of the materials used are readily available and manufacturing is not incredibly difficult. Inverters and control circuitry is way more of a risk than the panels themselves but there are stockpiles and sources that are good for many places
That's certainly an issue, but much, much less critical than gas.
Are people really suggesting the opposite: that the renewables transition should not occur, and the EU should continue to burn gas from more and more desperate sources, until it can be onshored?
That's nowhere near the level of dependency that fossil fuels bring.
Barring significant damage, you can maintain approximately your current level of power generation for years at a time without more than routine maintenance.
Fossil fuel power requires constant input of, well, fossil fuels.
So while what you're saying is true, it would be a ludicrous stretch to say that it brings solar panels within a few orders of magnitude of fossil fuels in terms of dependency on foreign powers.
And panels last forever, ensuring that Europe won't have to deal with panel manufacturers ever again.
Historically panels are generally considered to be exhausted after 30 years of service, although even that means they're down to 80% of their original capacity.
The more failure prone component is the inverter, by a huge margin.
Warranty lives tend to be in the 20+ year range and potential lifespan even higher, so .. kinda?
By coincidence I had my solar panels installed round about the time construction started on Hinkley Point C. They've already paid back their installation cost. I don't expect to replace them any time soon.
You have 20 years after buying them to set up a local supply chain.
Clearly uneducated take.
The photos hitting my solar panel don’t travel through the straight of Hormuz.