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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

#251

Post by microdrum »

jstsch wrote: post #12

Battery prices are getting really low, if you're willing to do some DIY. Just received a 15kWh battery from China. A 'Humsienk'. Combined it with a GroWatt SPA3000TL-BL inverter. Total price, 1600 euros. So close to the magical 100 euros per kWh. Driving it with some interesting combinations of Raspberry PI's and serial interfaces and custom written Go code, but it works... :)

Yup, Growatt is the Chinese OEM that Base Power white labels to pretend it does US manufacturing. In fact this stuff is low quality. You need to be careful. There are gradations of quality at cell, pack, inverter, control levels. You will be crushed if you realize you AliExpressed your way to a home power "solution" only to have it fail young.

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

#252

Post by bluGill »

secabeen wrote: post #221
Veserv wrote: post #216

Earlier quoted context omitted.

What do you mean? It did pan out for Tesla. Faking a single demo granted them 75% more ZEV emissions credit government subsidys [1]. That increased their profits by hundreds of millions of dollars. All they had to do was go on stage and “swap” a battery without any clear video of the process and never “demonstrate” it ever again. This is a company known for faking prominent demos like the FSD demo (where it crashed i…

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?

The bigger risk is you need a standard battery pack. Sure you can put 3 in a truck or something, but you lose all the space that a standard battery size wouldn't fit but you can cram a cell in. Electric car design is about stuffing batteries where there is space - you need a lot of cells, but the individual cells are small.

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

#253

Post by torginus »

jillesvangurp wrote: post #165
mbesto wrote: 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…

There's going to be a bloodbath in that market in the next years. There are a lot of battery producers and most of them are not producing at full capacity. At the same time, manufacturing cost is dropping as well. Some battery makers are producing batteries at a cost level of around 60$ per kwh. At that cost, the 16kwh battery would come out below 1000$ (not the same obviously as the product price). Sodium ion might…

Majority of the world's battery manufacturing capacity is dominated by just a small handful of players:

https://en.wikipedia.org/wiki/List_of_electric_vehicle_batte...

Just 11 companies control 90+% of manufacturing capacity, I think they might need to adjust their ambitions in the face of demand, but I think most of them are too big to fail.

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

#254

Post by IAmBroom »

dymk wrote: post #101
latchkey wrote: post #85

Earlier quoted context omitted.

Having power when your entire neighborhood is off, priceless. [edit: yes, I assume you also get batteries, I know that solar alone doesn't magically power your house.]

99% of systems are grid tie, so unless you’re spending another $7k for an ATS and associated infrastructure or you’re 100% off grid, your power still goes off.

For others who aren't up on the lingo:

"An ATS (Automatic Transfer Switch) for solar is a crucial device that seamlessly switches your home's power between the utility grid, your solar panels/battery bank...

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

#255

Post by wang_li »

torginus wrote: post #248
mbesto wrote: 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 o…

The Ioniq has the ability to provide battery power out so you can plug your house in.

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

#256

Post by IAmBroom »

thescriptkiddie wrote: post #96
systemtest wrote: post #90

Earlier quoted context omitted.

-

battery life span is defined as when the reach 80% of their original capacity. it's possible that the decline will accelerate after that point but they aren't suddenly useless

Presumably an exponential decay, as for most tool lifetimes.

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

#257

Post by tzs »

mbesto wrote: 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…

It is interesting to compare to V2H systems.

I believe Chevy offers V2H on all 2026 Equinox EVs. Enabling this needs their V2H Enablement Kit and I believe you also need their PowerShift Charger. That would be around $38k for a 2026 Equinox EV LT, which has an 85 kWh battery, $6300 for the V2H Enablement Kit, $2000 for the PowerShift Charger. Installation via the company Chevy says to use is $2000-5000 according to the net.

That brings us to $51-52k, and would give 70ish kWh of usable backup capacity. That's around $750/kWh of capacity.

Getting that capacity with Powerwalls would require 5 of them and cost quite a bit more.

Plus, with the V2H approach when you aren't having a power outage you can use it as a car. :-)

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

#258

Post by torginus »

raddan wrote: post #199
jillesvangurp wrote: post #165

Earlier quoted context omitted.

There's going to be a bloodbath in that market in the next years. There are a lot of battery producers and most of them are not producing at full capacity. At the same time, manufacturing cost is dropping as well. Some battery makers are producing batteries at a cost level of around 60$ per kwh. At that cost, the 16kwh battery would come out below 1000$ (not the same obviously as the product price). Sodium ion might…

I installed a 16.5kWp ground-mount array a month ago. I live in the US Northeast, in a mountainous location that means we get late sunrises and early sunsets. Nevertheless, based on my one month of data, it looks like we can generate all the power we need for our household on a sunny winter day, excluding electric vehicles. Even on overcast days, we can sometimes offset a significant portion of our usage. My locale d…

Here in Europe, we got more than a month's worth of foggy, cloudy weather (something that looks like will keep being a thing), which is something I became painfully aware of as an owner of a solar setup.

No amount of battery banks can tide over such a long stretch.

By the way, let me ask you - considering your location, you must be getting a lot of snow, how do you deal with it, is it a problem? Panels are quite hard to reach on the roof.

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

#259

Post by testing22321 »

7.8kw on the roof here in Canada.

7.72MWh for the calendar year produced saving smack on $1000.

$5000 gov grant (free money)

Full remaining install cost covered by interest free loan, so we put that money onto the loan for the next 7 years, then get $1000 a year for the following 20 or more.

Complete no brainer.

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

#260

Post by dymk »

IAmBroom wrote: post #254
dymk wrote: post #101

Earlier quoted context omitted.

99% of systems are grid tie, so unless you’re spending another $7k for an ATS and associated infrastructure or you’re 100% off grid, your power still goes off.

For others who aren't up on the lingo: "An ATS (Automatic Transfer Switch) for solar is a crucial device that seamlessly switches your home's power between the utility grid, your solar panels/battery bank...

And I should clarify that you technically can get away with a less expensive interlock system, but you're still paying a few thousand dollars to have your panel replaced (unless you feel comfortable doing that sort of electrical work yourself).

Making a system non-grid-tie is comparatively expensive, that's why grid tie is so common. People think you add solar + batteries and you're ready for doomsday - not quite.

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