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‘Energy independence feels practical’: Europeans building mini solar farms

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Re: ‘Energy independence feels practical’: Europeans building mini solar farms

#251

Post by aaronmdjones »

labcomputer wrote: post #249
aaronmdjones wrote: post #169

Earlier quoted context omitted.

Yes they are. Current alternates direction, but power usually only flows in one direction, from the input terminal (from the bus bar) to the output terminal (that the circuit is wired into). If the circuit will be supplying power too (e.g. battery storage, an EV and EVSE that supports powering the house from the EV, etc) then you need a bidirectional RCBO. People with no differential fault protection need not worry a…

That’s an RCD, not a breaker. Guess the English still insist on using nonstandard terminology, like “lift”, “bonnet”, “torch”, and, apparently, “breaker”. Oh well.

This is not an RCD, it's an RCBO. It combines the functions of an MCB (Miniature Circuit Breaker) and an RCD (Residual Current Device) in one device, as specified by BS EN 61009 (Residual Current Operated Circuit Breakers with Integral Overcurrent Protection).

Re: ‘Energy independence feels practical’: Europeans building mini solar farms

#252

Post by hahn-kev »

therealdrag0 wrote: post #218
itsmek wrote: post #160

Earlier quoted context omitted.

Syncing them with electricity is easy. The hard part is preventing export to the grid which requires either a compatible smart meter that can communicate with your panels or a transformer clamp installed by an electrician. My understanding is some meters measure both directions equally so if you do end up exporting power you can conceivably increase your utility bill.

Why is preventing export hard? Just shut down production when the grid is down, which is how plug-in solar systems work.

The grid doesn't need to be down, your solar just needs to produce more than you're using.

Re: ‘Energy independence feels practical’: Europeans building mini solar farms

#253

Post by cenamus »

adrianmonk wrote: post #242
jamescrowley wrote: post #236

Earlier quoted context omitted.

My understanding is that is why they are limiting to 800w (~4A) at least in the UK's BS 7671 Amendment, which they consider well within the designed safety margins.

Hopefully nobody thinks "I'll save even more if I get two!" and plugs them both into the same circuit. Perhaps they could somehow detect each other and shut off.

I think that's the reason why the total allowed panel power is only 800W, any more than that and you have to get it properly installed. At least that's ~ the way it is in Austria, it's also pretty easy to check whether you have ~800 or way more hanging on off your balcony.

Re: ‘Energy independence feels practical’: Europeans building mini solar farms

#254

Post by raverbashing »

hvb2 wrote: post #151
theshrike79 wrote: post #130

Earlier quoted context omitted.

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.

Storing hydrogen is no small feat. Especially for long duration

Might be cheaper than batteries, and if you can store it for 24h to compensate day/night cycles you're still making money

Re: ‘Energy independence feels practical’: Europeans building mini solar farms

#255

Post by lpcvoid »

mbgerring wrote: post #200
fc417fc802 wrote: post #195

Earlier quoted context omitted.

You can decentralize residential power without doing the same for industrial loads. Doing so is a mixed bag. It's somewhat more expensive however it's less prone to failures during natural disasters, failures aren't outside of your ability to fix, and it isn't subject to politics to nearly the same degree. When you consider the logistics of strengthening the last mile of residential to accommodate EVs in a sparsely p…

A good friend of mine is a solar installer in rural California, and he is booked solid building battery and solar systems sized to charge cars, because depending on PG&E is worse than spending the money to go off-grid.

Yepp. Grid defection is a trend all across the world right now in sunny climates. I live in Germany and can unfortunately not do this, but if I had thr sun hours of California, you can bet I'd build 300kWh of LiFePO4 and as much solar as my roof allows, and cancel all my expensive contracts.

Re: ‘Energy independence feels practical’: Europeans building mini solar farms

#256

Post by lpcvoid »

yawaramin wrote: post #245
ericd wrote: post #204

Earlier quoted context omitted.

It's aluminum, glass, silicon, and some conductive metal. Surely you all have those materials. And even if you don't make them yourselves, they aren't make and then burn like fossil fuels, they are durable infrastructure, you don't have to replace them often - they have an expected lifespan of >30 years. Buy as many as China will sell you, and once you have more than enough installed, you're good for a long time, reg…

> expected lifespan of >30 years More like > I think being reliant on the fossil fuel supply chain for so long France isn't. And they are net exporting their (nuclear fission) electricity to their neighbours who shut down nuclear power plants.

Yes, and France currently has a huge problem with keeping their plants online in the summer when it's too warm. And building new plants is outrageously expensive, see Hinkley Point C. Oh, ans you still need to import fission material, so you're dependent again on other countries. Nuclear was good in the 70s, now it's beaten thoroughly by renewables.

Re: ‘Energy independence feels practical’: Europeans building mini solar farms

#257

Post by Panzer04 »

password4321 wrote: post #172
oliwarner wrote: post #77

Earlier quoted context omitted.

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 che…

I am not very well versed on this topic but I believe the balcony solar products market one of their safety features as "anti-islanding protection". Personally I wonder what happens if multiple balcony solar systems are connected... can each still tell when the grid is down since the other power source is active? https://www.digikey.com/en/articles/anti-islanding-and-smart...

Unless there's so much generating capacity available that they can power the entire connected grid, no.

Consider 100 homes on a power line network and the breaker trips. They probably draw 50kW on average, more if it's hot or cold and AC is on. Unless there's enough power generation available to power that entire load, voltage will drop and any halfway reasonable hardware should give up.

Re: ‘Energy independence feels practical’: Europeans building mini solar farms

#258

Post by Panzer04 »

PaulDavisThe1st wrote: post #211
horsawlarway wrote: post #113

Earlier quoted context omitted.

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 di…

The dilemma here for me is twofold: (1) while it makes sense to me to distribute generation, because there are not really any significant economies of scale other than purchasing power, it doesn't make sense to distribute storage which, IIUC, has huge economies of scale. (2) being fully off-grid where I live requires homes that can be heated in winter with heat pumps that require less than mid-winter generation level…

I don't think there's any particular economy of scale to renewables beyond amortising installation costs.

This is a really big component in most western countries, so big installations are always going to be more cost effective, but there's nothing special about storage vs solar or anything else.

I suppose storage is smaller, so you don't have to pay for much land like you would solar (and where homeowners are basically utilising an underused resource so they have a cost advantage in that respect)

Re: ‘Energy independence feels practical’: Europeans building mini solar farms

#259

Post by Panzer04 »

laurencerowe wrote: post #154
mbgerring wrote: post #136

Earlier quoted context omitted.

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.

I'm not convinced we'll ever see mass deployments of batteries to homes, not because of the fossil fuel lobby but because of the economies of scale from installing grid sized batteries at strategic points in the transmission network. In California grid scale batteries have capital costs of around $125/kWh to $155/kWh while a home battery might be 20x that including installation.

That's because home battery providers aren't competing on price yet. The market is still small, the risks are high and they need to figure things out.

Once the early adopters run out they will have to start competing on price to make sales. There's no justification for a home battery when they charge 10k for 10kwh as they do now - only early adopters and government subsidies getting it over the line.

IMO home batteries should be a relatively easy install in principle, it's just still in that early expensive phase.

Re: ‘Energy independence feels practical’: Europeans building mini solar farms

#260

Post by Moldoteck »

cjrp wrote: post #4

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/

Plugin solar doesn't make much impact anyway even in Germany because of shades/angles and most of the time- no storage. Rooftop is another discussion
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