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What a year of solar and batteries saved us in 2025

scotthelme.co.uk

11–20 of 368 posts

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

#11
post #2

Good analysis. And kudos to the author for saving money. But still 21.6MWh per year excluding solar production seems too high for a household. I use electric heating and drive an electric vehicle, and my household annual energy consumption is about one fifth of that.

From the article: "My wife and I both drive electric cars" That probably explains it.

A single extra charge in a month can really mess the stats up.

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

#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... :)

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

#14
post #2

Good analysis. And kudos to the author for saving money. But still 21.6MWh per year excluding solar production seems too high for a household. I use electric heating and drive an electric vehicle, and my household annual energy consumption is about one fifth of that.

Not all homes are made equal: different appliances & electronics from different vintages, etc.

I have 2 EVs (Tesla and BMW), an electric oven, and a homelab rack (but no HVAC), and my usage was 34.4 MWh last year — with 100% from Solar and Powerwall.

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

#15
post #10

Why do people still go for tesla powerwalls when you can get BYD batteries with 70%+ more capacity for cheaper ? You can buy a BYD HVM 22.1 kWh for 6000 euros now (£5200) vs powerwall 2 13.5kwh for 7000 euros.

Brand trust?

(Yes, yes: insert Musk related joke here.)

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

#16
post #2

Good analysis. And kudos to the author for saving money. But still 21.6MWh per year excluding solar production seems too high for a household. I use electric heating and drive an electric vehicle, and my household annual energy consumption is about one fifth of that.

That’s about double the average household so I would imagine spending that money and effort into energy efficiency would pay off way better that solar and batteries.

The average household doesn't have two electric cars though

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

#17
post #2

Good analysis. And kudos to the author for saving money. But still 21.6MWh per year excluding solar production seems too high for a household. I use electric heating and drive an electric vehicle, and my household annual energy consumption is about one fifth of that.

I used about 64MWh last year, not counting what I used for EV charging (Which is on a separate meter). I also produced about 20MWh from Solar. With the EVs I would guess the total is around 70MWh.

Some of this extra is certainly my 6kw homelab + HVAC for that. ;)

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

#18
post #2

Good analysis. And kudos to the author for saving money. But still 21.6MWh per year excluding solar production seems too high for a household. I use electric heating and drive an electric vehicle, and my household annual energy consumption is about one fifth of that.

I'm an example more towards the middle.

In 2025 I produced 6.5MWh (solar) and consumed 12.7MWh (excluding solar production); this is a family of 4 in a 4 season climate with electric heating and a single electric car.

That was my highest year over the past 5 years.

An additional EV can really add up, especially if both people have long commutes.

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

#19
post #2

Good analysis. And kudos to the author for saving money. But still 21.6MWh per year excluding solar production seems too high for a household. I use electric heating and drive an electric vehicle, and my household annual energy consumption is about one fifth of that.

Not all homes are made equal: different appliances & electronics from different vintages, etc. I have 2 EVs (Tesla and BMW), an electric oven, and a homelab rack (but no HVAC), and my usage was 34.4 MWh last year — with 100% from Solar and Powerwall.

That’s an awful lot of power.

I’m waiting on a quote for an hvac that uses its waste heat for the home hot water. Im irritated that I’m cooling the house, pushing out hot air, and heating water at the same time.

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

#20
post #7
post #2

Good analysis. And kudos to the author for saving money. But still 21.6MWh per year excluding solar production seems too high for a household. I use electric heating and drive an electric vehicle, and my household annual energy consumption is about one fifth of that.

20MWh is around what my house used in both 2024 and 2025.

This number can mean wildly different things depending on the size of your house (and location).

I live in the Bay Area, CA in a 1,500 square foot house and consumed 7.8MWh in 2025 and 7.6 MWh in 2024.

Digging a bit more into our solar system data: We produced a bit over 9MWh in solar each year and it looks like our Enphase batteries discharged 2MWh each year.

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