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What a year of solar and batteries saved us in 2025

scotthelme.co.uk

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Re: What a year of solar and batteries saved us in 2025

#241

Earlier quoted context omitted.

Residential solar with batteries greatly aids the grid and reduces costs for the entire system. > The metals do build those batteries do not exist. Or put in a worse way, the mines do not exist. Lithium and sodium, the two most promising battery metals, are not usually mined, though in Australia I hear there is mining. It's more of a brine process. All across the US, frackers are finding that all that water they are…

I don't agree. Lithium and Copper are mined and given electrification scenarios there is a projected supply deficit: https://www.iea.org/reports/global-critical-minerals-outlook... Those prices are outdated now since practically all metals are surging. There has indeed been great growth in battery capacity but it's as I said nowhere near able to supply a country like Sweden during the winter. It is off by orders of m…

Your link does not support the idea of a supply deficit, at least that I see. Propel panicked about lithium under supply, prices surged and didn't even affect battery prices much, and now we are in oversuppply. The worst that can happen is lag time between demand increase and supply match, and there are substitutes for all key metals for most applications, even copper.

Every country will have to figure out how to supply its own power, but Sweden's seasonal variation in renewable resources is not likely to be fixed by batteries, even though batteries will be abundant and in massive supply throughout the rest of the world. If Sweden can't figure out, or merely can't, take advantage of great cheap new technology, they will be at a disadvantage compared to countries that will

> I know California has rotating blackouts already as it is

You don't know that because it's not true. Due to planning not taking into account climate change, there were a few days with demand above expected ability to provide capacity, but there were no blackouts because people were asked to voluntarily cut back on excessive cooling. That mere ask was more than enough to get through the few days. And it was fixed the next year, by what? By batteries! Adding nuclear wouldn't have helped, but batteries were the perfect solution. Perhaps nuclear can help Sweden, but it will be far more expensive than the solutions available to other countries.

It is quite funny that what I thought was US propaganda has been spread to Sweden for repetition. Even including the IEA report that doesn't say what people claim it says!

Re: What a year of solar and batteries saved us in 2025

#242
post #91

> The batteries can fill up on the off-peak rate overnight at £0.07/kWh, and then export it during the peak rate for £0.15/kWh, meaning any excess solar production or battery capacity can be exported for a reasonable amount. Honestly I didn't know this was allowed. I recently got a heat pump and am on a time-of-use tariff ( https://octopus.energy/smart/cosy-octopus/ ) and have been thinking about pulling the plug on…

Why wouldn't it be allowed? They're essentially renting their batteries and grids generally lack storage

Yeah not sure really. I thought these time of use tariffs were intended for charging EVs and using heat pumps, not charging batteries and selling the energy straight back to them later on in the day. But when you put it like that (decentralised grid storage) I guess it makes sense.

Re: What a year of solar and batteries saved us in 2025

#243
post #166

Earlier quoted context omitted.

> which would probably hae been another 3-5k if I could have found someone to do it. Yo. If you can find an electrician to stop by my house and turn a light switch off for less than 1000$, please inform me. I got a quote for 25k$ to install a system that size, and that price. City code has me by the balls: I can't modify my main panel without inspection, the inspector won't show up without a licensed electrician, and…

For 2500$ maybe you can pass the exam to become licensed yourself. Like do it over the weekends.

To get a journeyman electrician license in Texas, you need to have 8000 hours of documented on-the-job experience working under a licensed electrician[1].

So you'd need to find an electrician who will let for you work them on the weekends, and if you work 8 hours every Saturday and every Sunday, then it will take you 500 weekends.

A residential wireman license only requires 4000 hours[2], but I'm not sure if that kind of license would be good enough for the inspection.

---

[1] https://www.tdlr.texas.gov/electricians/apply/individuals/jo...

[2] https://www.tdlr.texas.gov/electricians/apply/individuals/wi...

Re: What a year of solar and batteries saved us in 2025

#244
post #51

Earlier quoted context omitted.

Almost all simulations I've done across 3 countries with 3 different payback models for selling back to grid (one of the three doesn’t allow selling back almost anything above your consumption), I could never make investing in Solar not being a gamble. You really need to gamble on odds of replacing equipment being very low for it to make sense. And in practice most people I anecdotally know that run it, after 5-7 yea…

im a systems engineer and cost analyst who has put together some modeling myself as well. as a personal investment on your house, i agree. The economic value of solar seems to be best applied as neighborhood or block purchases, like as part of a co-op or hoa. they would need dedicated infrastructure like a communal parking lot with solar overhead, or running them on the property line borders with an easement undernea…

This is also true of heating and cooling, and I've never understood why we (in the US) build relatively dense housing communities but don't implement things like this. Having a separate air conditioner for each home, especially in a condominium/townhouse complex, has never made sense to me as it's so inefficient compared to central heating/cooling.

Re: What a year of solar and batteries saved us in 2025

#245

Earlier quoted context omitted.

Battery swap was and remains really risky for anyone doing it. You're taking a $10k asset, and swapping it for another $10k asset of unknown provenance. Does anyone really want to be in a situation where they purchase a new Tesla with a brand new, max-range battery pack, then swap it once on a road trip and get one that's been used for 300k miles and is at 75% of original capacity?

As long as you can always swap your battery again I don't see the problem As long as the average battery health in the system is like 90% and the minimum is say 80% why would you care if you're getting a new battery every few days? If anything it removes a big cause of depreciation from your car

That is fine if you always are swapping. However if you normally charge at home that becomes a big deal - if your current battery wears out/fails because it has 500,000k miles on it are you out a new one? Do you pay for the tow to get to a swap station? Again, if everyone always swapped this would be easy to amortize and not a problem but the mixed use.

Of course this isn't a new problem. I know people who own their own welding gas tank - but they always swap the tank out. The place they swap at somehow handles when the tank needs to be re-certified - and people don't ask questions.

Re: What a year of solar and batteries saved us in 2025

#246
post #52

It's wild how overpriced Tesla Powerwalls are. 16 kWh battery with all of the UL supported listings etc = $3300 [0] 13.5 kWh Tesla Powerwall is $12k~$15k You would get your return way back quicker. [0] - https://www.ruixubattery.com/product-page/lithi2-16-battery-... EDIT: As others have pointed out, powerwalls have inverters built in so it's not totally apples to apples. You can get a beefy inverter for $5k and it's…

For what it's worth, Tesla PV/batt inverters are bad, almost as bad as the Chinese manufacturers mentioned ITT. PW3 has very high failure rate ~10%+RMA, not good enough IMO to be in the path of power at my house.

(Their motor inverters are world-class, but totally different topology)

Re: What a year of solar and batteries saved us in 2025

#247

Earlier quoted context omitted.

> which would probably hae been another 3-5k if I could have found someone to do it. Yo. If you can find an electrician to stop by my house and turn a light switch off for less than 1000$, please inform me. I got a quote for 25k$ to install a system that size, and that price. City code has me by the balls: I can't modify my main panel without inspection, the inspector won't show up without a licensed electrician, and…

2019 prices, but it was $487 to move a receptacle from under a window to the left of the window prior to making that window opening a french door. In 2025 it was $1,100 to have an EVSE put in, including permit fees. I'm in Pennsylvania. Working with my township to get a permit / inspection was horrible -- they dragged their feet for months! I have to believe that I am one of a few people in my township who have done…

Weird. I'm in PA, and my electrician quoted me a flat fee of $100 for replacing my outlets with GFCIs (each).

Re: What a year of solar and batteries saved us in 2025

#248
post #52

It's wild how overpriced Tesla Powerwalls are. 16 kWh battery with all of the UL supported listings etc = $3300 [0] 13.5 kWh Tesla Powerwall is $12k~$15k You would get your return way back quicker. [0] - https://www.ruixubattery.com/product-page/lithi2-16-battery-... EDIT: As others have pointed out, powerwalls have inverters built in so it's not totally apples to apples. You can get a beefy inverter for $5k and it's…

A small thing I want to remark is that at that price, a Model 3 costs less than 3x, and has more than 3x the battery capacity.

Considering DC connectors on EVs provide a direct electrical connection to the battery terminal, and the charge-discharge circuitry in residential hybrid solar inverters can handle them just fine (provided it supports the voltage ranges, but people did this).

I think it's an enormous missed opportunity, that the most common charger standards don't support this (CCS2 doesn't, Chademo does, no idea about NACS)

If this was a thing, I think it would completely reshuffle the EV market, I don't know how used residential batteries depreciate, but I doubt they lose more than half of their value in 5 years like EVS do.

Re: What a year of solar and batteries saved us in 2025

#249
post #52

It's wild how overpriced Tesla Powerwalls are. 16 kWh battery with all of the UL supported listings etc = $3300 [0] 13.5 kWh Tesla Powerwall is $12k~$15k You would get your return way back quicker. [0] - https://www.ruixubattery.com/product-page/lithi2-16-battery-... EDIT: As others have pointed out, powerwalls have inverters built in so it's not totally apples to apples. You can get a beefy inverter for $5k and it's…

I think "overpriced" depends a lot on what problem you're trying to solve

A statement so vague as to be tautologically true.

Re: What a year of solar and batteries saved us in 2025

#250
post #166

Earlier quoted context omitted.

> which would probably hae been another 3-5k if I could have found someone to do it. Yo. If you can find an electrician to stop by my house and turn a light switch off for less than 1000$, please inform me. I got a quote for 25k$ to install a system that size, and that price. City code has me by the balls: I can't modify my main panel without inspection, the inspector won't show up without a licensed electrician, and…

For 2500$ maybe you can pass the exam to become licensed yourself. Like do it over the weekends.

"licensed electrician" is also timewalled behind a lengthy apprenticeship.

From google's llm "..requiring 8,000 hours of on-the-job training (OJT) under a Master Electrician .."

so even if you could pass the test you still don't get to become licensed until you've paid your dues in terms of time.

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