Tesla Powerwalls

[hightower]

I've got a keen eye on Tesla Powerwalls, and I think there'll be a future in it. I think I'll be trying to get sorted as a certified installer. However, does anyone know of the current savings of using one? I know they are traditionally designed for use with solar systems, but surely it could be just as cost saving to install one, and have it charge up on an off-peak meter, and then have it provide the stored energy during peak hours?

 

[LeeH]

When I had my solar put in I was told the maths just doesn't work. Yet...

I would guess paying for premium on peak units would wipe out any savings. Let alone the initial outlay of the unit.

Just a feeling, I haven't ran any numbers.

 

[hightower]

I haven't ran any numbers, but have seen that you could save £900 a year by having one installed on economy 7. Now, I take sales figures with a pinch of salt, and to save £900 a year means you had to be spending £900 a year in the first place.

But let's say this thing runs on E7, and (for arguments sake, not done much looking) E7 off-peak is half the cost of peak. And for the sake of keeping things simple, let's say this powerwall will keep an average house running all day. So essentially, that means your electricity bill is halved. Let's say my bill was £400 for electric, surely that means I can save £200 a year. Okay, the boxes are about £5k which will put repayment at 25 years, but the boxes are surely going to come down in price in the foreseeable future.

Sorry, very basic maths etc, but I reckon this is going to have a lot more potential than solar. If you already have solar, this stuff is going to double it's usefulness.

 

[Scuba]

Given the duty cycle and the lifespan of the Powerwall I calculated that you would need to be buying one at a maximum of £2,400 to break even. That's with me having a large solar PV array. As it costs much more than that then it's a waste of money.

 

[Worcester]

If you do it purely on the electricity savings no they don't make economic sense.

Germany has a grant for installing battery systems, and the way their electricity and FiT tariffs work with peak load shedding it makes sense there.

Here you'll do it for other reasons - we have one system going in to power key circuits for up to 8 hours in case of brown / black outs. Cost was not a consideration.

 

[hightower]

Doesn't matter anyway. I applied to be a certified installer and they knocked me back, on what grounds I've no idea but based on the questions they asked I reckon it's because they want large companies not little one man bands

 

[Scuba]

Doesn't matter anyway. I applied to be a certified installer and they knocked me back, on what grounds I've no idea but based on the questions they asked I reckon it's because they want large companies not little one man bands

You have to be an approved Solaredge installer (or perhaps some other company approved by Tesla) before you can get on the course.

 

[infinity]

Its not just large companies, we became accredited and were small, its probably down to your PV experience as you would need to be MCS accredited at a minimum.

 

[hightower]

You had any installs of it @infinity? What's it like?

 

[infinity]

Yes we have installed around 15 of them. Its a nice enjoyable job actually, can be challenging manoeuvring it around as it weighs 100Kgs
Have done variety of SolarEdge and AC coupled SMA versions. SMA had said off peak charging would be available by the end of last year via a software update but its not happened yet!

 

[infinity]

there are a few photos of the power walls installed on our Facebook page here Infinity Energy Services Ltd | Facebook - https://www.------------/InfinityEnergyLtd/
or our website, Infinity Energy Services