Specification for a Solar System

EricMears

Not all 'dial meters' will run backwards !

It's probably not a criminal offence for an occupier "not to notice it's happening" but that doesn't make it 'legal' !  You are supposed to notify your supplier if it happens when they should arrange for meter to be replaced at their expense.

ABrass

Tesla have announced they're not going to sell PowerWall unless it's also bundled with their solar systems. I don't know if that's already taken effect or not or if it's just for the US or worldwide.

Grumpy_chap

ABrass said:

Tesla have announced they're not going to sell PowerWall unless it's also bundled with their solar systems. I don't know if that's already taken effect or not or if it's just for the US or worldwide.

I suspect, hope, assume, that does not include UK as Tesla Solar Roof is not yet available in the UK.  I don't know though.

Solarchaser

I wonder if it's a lack of availability on batteries with vehicle production ramping significantly,  they probably are prioritising that.

I'm certain, as Eric says that knowingly letting the meter run backwards is not legal.

But you know the financial case for batteries, isn't really there yet.
I mean with optimisation and tou tarrifs it can be made to break even in 10-12 years, as long as you pick the right size of batteries for your usage, but its by no means a given.

Verdigris

Solarchaser said:

I wonder if it's a lack of availability on batteries with vehicle production ramping significantly,  they probably are prioritising that.

I'm certain, as Eric says that knowingly letting the meter run backwards is not legal.

But you know the financial case for batteries, isn't really there yet.
I mean with optimisation and tou tarrifs it can be made to break even in 10-12 years, as long as you pick the right size of batteries for your usage, but its by no means a given.

Powerwalls are part of the Tesla business model. They are a secondary use for the cells in the automotive batteries, once they have dropped to about 80% efficiency.

ABrass

Verdigris said:

Solarchaser said:

I wonder if it's a lack of availability on batteries with vehicle production ramping significantly,  they probably are prioritising that.

I'm certain, as Eric says that knowingly letting the meter run backwards is not legal.

But you know the financial case for batteries, isn't really there yet.
I mean with optimisation and tou tarrifs it can be made to break even in 10-12 years, as long as you pick the right size of batteries for your usage, but its by no means a given.

Powerwalls are part of the Tesla business model. They are a secondary use for the cells in the automotive batteries, once they have dropped to about 80% efficiency.

Source? As far as I know they're using new cells, not least because there aren't enough second hand cells available to do that.

The main problem with reusing ex EV batteries for stationary storage is that the batteries are lasting too long so there's no supply.

Martyn1981

Grumpy_chap said:

ABrass said:

Tesla have announced they're not going to sell PowerWall unless it's also bundled with their solar systems. I don't know if that's already taken effect or not or if it's just for the US or worldwide.

I suspect, hope, assume, that does not include UK as Tesla Solar Roof is not yet available in the UK.  I don't know though.

They are launching the PW+, which takes the PV inverter and some Gateway kit 'inside', hence being bundled with PV. I've no idea if the PW2 is to be discontinued, hadn't heard that, but the main problem is that there simply isn't enough battery capacity yet, so PW2's are competing with the cars, the much larger powerpacks, and mega packs, and even delaying the rollout of the semi, since they'll take up around 10 cars worth of batteries, but not 10x the revenue and profit.

As Eric says, not all dial meters will go backwards, and even those that do, may only go backwards on the unit dial. A friend of mine had one of these + PV for about 6yrs, but did tell the company, several times (that's important). If the dial started at 9 in the morning, then a sunny day could 'remove' 9 units, but if it started on a zero, he got no 'cheeky' savings.
For a company to suggest they all go backwards, and that it's legal, is pretty disgusting.

PS. I've never heard that Powerwalls (etc) use secondhand car batts, though of course, many forms of stationary storage are evolving using BEV batts in a second life roll.

Grumpy_chap

Give me an idea, though:
https://www.autotrader.co.uk/car-details/202105032149899
Big battery with a free car!

Verdigris

Automotive batteries pretty hard work to pull apart. There are a number of Youtube videos on the subject.

Martyn1981

ABrass said:

Verdigris said:

Solarchaser said:

I wonder if it's a lack of availability on batteries with vehicle production ramping significantly,  they probably are prioritising that.

I'm certain, as Eric says that knowingly letting the meter run backwards is not legal.

But you know the financial case for batteries, isn't really there yet.
I mean with optimisation and tou tarrifs it can be made to break even in 10-12 years, as long as you pick the right size of batteries for your usage, but its by no means a given.

Powerwalls are part of the Tesla business model. They are a secondary use for the cells in the automotive batteries, once they have dropped to about 80% efficiency.

Source? As far as I know they're using new cells, not least because there aren't enough second hand cells available to do that.

The main problem with reusing ex EV batteries for stationary storage is that the batteries are lasting too long so there's no supply.

I can't think what to search for now, but I saw a really funny set up a while back, on a very small island, which was using ex BEV batts for power. They had, I think, some banks of Leaf batts, connected to controllers, but the star of the show, was a complete Tesla underbody, on the wall (or on it's side, against the wall), so it didn't just use the batts, but the whole system ..... sheer genius.