Battery only install

born_again

https://forums.moneysavingexpert.com/discussion/comment/81972430#Comment_81972430

As per OP around 6kWh a day. When they are not being charged.

While bidirectional charging would be great. There is the cost factor. New charger & new car required. Which would make the cost of a solar install like dipping into pocket to buy something 🤷‍♀️

Reed_Richards

New bidirectional charger say £1.5k at worst? New car you are going to buy anyway, every so often, so does that count? And a few EVs are already capable of bidirectional battery operation.

blanched_jelly

https://forums.moneysavingexpert.com/discussion/comment/81972184#Comment_81972184

I think this is where we’re just looking at it from different angles.

I completely agree a Powerwall is a more premium, feature-rich product - no argument there. But calling something like Fox a “compromise” only really makes sense if it fails to meet OPs needs, and in this case it doesn’t.

For ~6kWh/day usage on a battery-only setup, ~10kWh usable capacity already does the core job (load shifting off cheap overnight rates) pretty much optimally. Beyond that, extra capacity only adds value if it’s actually cycled - otherwise it’s just unused headroom that’s been paid for upfront.

On the future-proofing point, that’s fair in principle, but it cuts both ways. Tech, tariffs, and use cases (like EV integration or V2G) are evolving quite quickly, so there’s also a case for not overcommitting capital today based on assumptions a few years out.

On support/warranty, I get why people rate Tesla highly, but in practice most mainstream systems (Fox, GivEnergy, Solis etc.) are installer-supported first anyway, and the real-world experience tends to depend as much on the installer as the brand.

So I’d say it’s less “premium vs compromise” and more Tesla = higher upfront cost, more features, stronger ecosystem, Fox = lower upfront cost, simpler, but still does the core job effectively

For someone like @born_again specifically looking for a cost-effective way to shift overnight energy now, I don’t think Fox is an unreasonable choice at all.

JKenH

https://forums.moneysavingexpert.com/discussion/6665135/battery-only-install

You have said average usage is around 6kWh a day peak time. Can you clarify. Is that 6kWh a day all at peak time or 6kWh a day peak usage plus some other consumption, and if so, how much? You may get 6 hours at cheap rate but if your base load is, say, 200 watts then over the other 18 hours that adds another 3.6kWh which would be at peak rate.

Average electricity use is a problematic term as most of us use much more in winter than summer. Is yours flat through the year?

Martyn1981

https://forums.moneysavingexpert.com/discussion/comment/81972889#Comment_81972889

Have you got a link to any of those? I've been trying to follow news/progress, especially in Aus, but keep seeing suggestions of £3k+ for the chargers that are semi-available. But appreciate there are hopes for lower prices.

Have always loved the idea and potential of V2G for national grid support, but the tumbling cost of batteries (demand side and grid), may leapfrog V2G, if charger costs don't come down a lot.

born_again

https://forums.moneysavingexpert.com/discussion/comment/81972889#Comment_81972889

TBH, I have no intention of changing car. Mine is not capable, & to get something of the size needed (have to carry wheelchair) is not going to be on the cheap side.

Octopus announced mid 25 that they were going for BYD Dolphin with V2G, still has not in the marketplace. Waitlist if you want..

So clearly not a easy to do solution. Given the capability of Octopus, BYD one of the biggest battery manufactures & Zaptec for the charger.

born_again

https://forums.moneysavingexpert.com/discussion/comment/81972957#Comment_81972957

Peak usage inc base load (05:30 to 23:30) is a average of 6kWh over the year, when not charging car's. As sometimes IOG gives daytime charging, which is at off peak rate. So have not factored in these days.

Base load from off peak (23:30 to 05:30) figures is around 1 kWh, again all year & not days when a car was charging.

Someone is home 24/7 so electric usage is pretty consistent all year. Gas heating

While somedays we may go to 10kWh or just over, I'm not bothered about getting a bigger than 10kWh battery (even knowing it is not a full 10kWh)

As many days we use sub 6kWh, so could export the unused (not calculating this in at all, as not a given)

In terms of eco systems I'm a Andriod person, rather than a Apple (Tesla) where everything is tied in.

ed110220

I've got solar and battery storage and my feeling is that at present EV tariff rates that offer very cheap overnight electricity, just battery storage probably gives better savings than just solar. It does of course depend on the install prices you can find.