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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

#171

Post by Rebelgecko »

systemtest wrote: post #125
coryrc wrote: post #106

Earlier quoted context omitted.

The worst that happens is you get paid back at the wholesale rate (from your bill, not live market price) instead of discounting kwh-per-kwh.

But is that rate always positive? Where I'm from during peak sun hours, the rate is negative and you end up paying money to deliver money to the grid. They do this to incentivise you to decouple your solar installation during peak sun hours so the net doesn't get flooded with too much energy.

In CA it can be 0 but not negative.

Depending on when you signed up for NEM you may have a guaranteed floor like 4¢/kWh or even much more.

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

#173

Post by bob1029 »

HexPhantom wrote: post #154
bob1029 wrote: post #139

The rooftop solar game in Texas is strongly into scam territory. Most homes I see with panels on the roof are two story homes where you have a negligible amount of area to work with relative to interior space. There was a point where you'd have to deal with a door-to-door salesman approximately every 48h for an entire summer. The most realistic residential installation I've seen was firmly on the ground at a ~2 acre…

I think you're mixing two very different things: the tech and the sales channel

I was hoping to illustrate that without a hyper-aggressive sales campaign not as many people would have gone along with a bad installation.

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

#174

Post by dabeeeenster »

domh wrote: 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…

I just had Solaredge battery installed in my house in the UK (Had a solaredge PV and inverter so made sense even tho it was more than other setups). If you are up for a challenge https://springfall2008.github.io/batpred/ is AMAZING and basically optimises when to charge and discharge your battery.

I've got a heat pump and think my paypack period is going to be about 6 years.

Hit me up on bluesky (in profile) if you want more info!

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

#175

Post by lostlogin »

vel0city wrote: post #30
lostlogin wrote: post #11

Earlier quoted context omitted.

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

An average EV battery is what, around 70kWh? Add in a bit of charging losses and we'll say maybe 75kWh being generous here, and that's assuming a nearly dead battery to a full charge. Doing that every month is then 900kWh, or 0.9MWh/yr. That's ~4% of the energy usage of 21MWh/yr. An average EV gets what, ~3.5mi/kWH? An average US car does ~12,000mi/yr. That theoretical average EV would then use ~3.5MWh. Two would be…

That percentage of total usage is tiny, I agree.

We have one car and charge it quite often.

I just checked last month: 184kwh went into the Leaf. We used 557kwh in total (excluding the car charging).

We generated 1170kwh.

The key thing for me is the wild energy usage from the house. It’s a lot.

Edit: Your car energy usage calculation works out awfully close to what we use.

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

#176

Post by toomuchtodo »

bob1029 wrote: post #173
HexPhantom wrote: post #154

Earlier quoted context omitted.

I think you're mixing two very different things: the tech and the sales channel

I was hoping to illustrate that without a hyper-aggressive sales campaign not as many people would have gone along with a bad installation.

Find a solar coop if you can to avoid the sales pain. They will assemble a group of homeowners and bid the entire group install out to achieve cost efficiency. Ground installs are cheaper and easier, imho, whenever possible (but depends on land availability and favorable solar insolation).

http://solarunitedneighbors.org/ | https://solarunitedneighbors.org/locations/

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

#177

Post by megaman821 »

bob1029 wrote: post #139

The rooftop solar game in Texas is strongly into scam territory. Most homes I see with panels on the roof are two story homes where you have a negligible amount of area to work with relative to interior space. There was a point where you'd have to deal with a door-to-door salesman approximately every 48h for an entire summer. The most realistic residential installation I've seen was firmly on the ground at a ~2 acre…

For homes, solar car ports and pergulas look attractive if you are land constrained. No holes in your roof, and it is Texas, so more shade is always appreciated.

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

#178

Post by itsamario »

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…

Companies like Schneider electric have systems for 25-50% the hyped brands but they don't provide batteries.

This is the company that owns APC so its not like theyre new or untested. They just don't bother with brand awareness

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

#180

Post by fastasucan »

lm28469 wrote: post #43
rokkamokka wrote: post #31

Earlier quoted context omitted.

Heatpumps are not a gimmick - they're an excellent technology with lots of efficient and effective uses :)

Overly complex and fragile in the long run, the savings are meaningless if you're already self sufficient. I'd much rather spend the money in insulation and self sufficiency than these voodoo appliances. That's my reasoning my new build house with plenty of land. In other scenarios it might be more beneficial to go for them.

Thwre is nothing voodoo about heat pumps. Not really that complex and not at all fragile either.
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