Does anyone actually have their battery where the aesthetics matter? Are they not just in a garage or in the loft (my givenergy 8.2 battery is in the loft)...couldn't care less what it looks like...but I like the look of my electricity bill because of it and my solar...last week's electricity bill was 36p
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Powerwall versus Givenergy batteries
- Thread starter spon88
- Start date
Mine's in a shed but some are mounted on outside walls so aesthetics and footprint might be a consideration.
squarepeg77
Member
Does anyone have an indicative cost for the new 9.5kWh Givenergy battery vs 8.2kWh? The one company I spoke to about it was very vague and wouldn’t be pinned down to a number
This website gives a good indication of costs...has the 8.2 in there currently but not the 9.5
Worth a gander though
midsummerwholesale.co.uk
Worth a gander though
Midsummer Wholesale
Midsummer Wholesale - suppliers of PV panels, inverters and system components to solar installation companies
midsummerwholesale.co.uk
I saw a comment somewhere that suggested a small increase on current prices. Not been able to validate yet though. I'll be happy to wait a few months with the solar going in first. That said, feedback from suppliers is slow all round at the moment
I looked at the powerwall and Givenergy batteries when looking for replacements for my old batteries. Powerwall was too expensive for me and Givenergy wanted to install their own inverter when I had a perfectly good one already. After a lot of debate, I went for the pylontech us3000c. At about £1000 for 3.5kWh they were good value, had good write ups, we're easy to install, their own integrated BMS and had a 95% discharge. I got 5, giving me 17.5 kWh approx 16kWh useable. They're mounted in a 21u computer server cabinet in the garage. The entire setup cost about £5500 without the inverter, which I already had. That would be about £1200.
So £6700 for a 17.5kWh system. Givenergy quoted me £7500 for the one battery and inverter. Payback for me is just over 6 yrs. Sooner if prices go up.
I'm just trying to make the point that there are other options if you look beyond the obvious ones.
Hope this helps someone.
So £6700 for a 17.5kWh system. Givenergy quoted me £7500 for the one battery and inverter. Payback for me is just over 6 yrs. Sooner if prices go up.
I'm just trying to make the point that there are other options if you look beyond the obvious ones.
Hope this helps someone.
Mind explaining your pricing? From the limited quotes I’ve had (based on the 8.2) it was perhaps 65% of the power wall 2 - but not two of them - that’d be at it over the pw2 price
I think the best pw2 price I’ve had is £9200 installed for a standard install.
Technically be wary of things like 100% discharge. Likely that just means the 9.5kwh battery is actually a 10.5kwh battery with 10% reserved that you don’t see so they can say 100%. In my opinion that’s sensible - just tell me the usable space, but may be worth checking
Also worth checking is how you’ll use it. The powerwall can be a bit clever for its own good and try to predict solar generation and not always get it right. In my case I need a mix of overnight cheap rate + top up with solar but it seems hard to do that because Tesla don’t give you full control. That has me leaning towards the givenergy
I think the best pw2 price I’ve had is £9200 installed for a standard install.
Technically be wary of things like 100% discharge. Likely that just means the 9.5kwh battery is actually a 10.5kwh battery with 10% reserved that you don’t see so they can say 100%. In my opinion that’s sensible - just tell me the usable space, but may be worth checking
Also worth checking is how you’ll use it. The powerwall can be a bit clever for its own good and try to predict solar generation and not always get it right. In my case I need a mix of overnight cheap rate + top up with solar but it seems hard to do that because Tesla don’t give you full control. That has me leaning towards the givenergy
Also - why are you thinking about two inverters? I wondered about the limited output of the givenergy but others have said it’s not usually a practical limitation except short occasional peaks that wouldn’t justify the increased cost and complexity.
What’s your estimated house base load and extended peak usage? - during the day, as off peak you could use the grid rather than battery
For others: does givenergy not do an AC coupled inverter or can I use the hybrid as one? Needs to be added to an existing pv without changing that inverter (to avoid FIT impact)
What’s your estimated house base load and extended peak usage? - during the day, as off peak you could use the grid rather than battery
For others: does givenergy not do an AC coupled inverter or can I use the hybrid as one? Needs to be added to an existing pv without changing that inverter (to avoid FIT impact)
Yes, I'd been given some verbal pricing which now appears to be a bit off. I'm still waiting to get firmer quotations and specs. I'd also been confused about ancillary items such as inverters. That said, GE still looks a lot more cost-effective and I may be able to stretch to two batteries on the back of that. But still lots of data to gather. I also hear what you are saying about the Powerwall perhaps being a bit too clever depending on circumstances. I have a solar designer in Notts coming back to me on that - he's a Powerwall advocate but says it can be quirky. Hopefully I can trust someone to understand my needs and come up with a suitable design.
We use an av of 25kwh per day, maybe a third of that in a busy home office with PCs, screens, servers etc.
Peak would be when the kids run a 10.5kw shower and when the car is charging - the latter is irregular as we don't do a great deal of mileage. I'm busy trying to get a more granular view of our usage. Another thing I'm trying to understand is how to preferentially charge the car on cheap grid power rather than flatten the battery - presumably you can control that? I have lots of daft questions I'll gradually work through
Either octopus go and tell the battery not to discharge (both should be ok here as they’d be charging then), or intelligent octopus and either tell the battery you have the basic 6 hour block or do a fancy automation like mentioned
I personally would already expect to charge the car off peak so wouldn’t factor it into my daytime load calculations. Shower fair enough but how long is the shower on for each day? May be worth doing the math to see if your spikes over 5kw are worth the extra £1000-1250 for a second inverter
I personally would already expect to charge the car off peak so wouldn’t factor it into my daytime load calculations. Shower fair enough but how long is the shower on for each day? May be worth doing the math to see if your spikes over 5kw are worth the extra £1000-1250 for a second inverter
2 inverters "work" but the software isn't ready for dual inverter setups.
Example: Inverter 2 doesn't know what inverter 1 can power the house from solar, so that cheap power you purched at night is being used by inverter 2, while you're dumping the excess solar to grid from inverter 1.
You can charge both at night and you can discharge off peak. I have limited my power to as little as 5p average with 16.6kw to use in peak (+7 kWh hot water generation by heatpump, plus car)
I limit my non solar inverter output for continuous load (400w) and let the other handle peak.
Multi inverter logic is expected this year.
You can chain batteries to one inverter, the problem is charging them in your cheap window.
RedMod3
Member
Yes, we have a double garage and my PW is mounted on the right hand side as I drive in. Had it been much wider, I would not have been able to easily open the car door.
Thats one of my future plans. To increase the amount of solar panels, get DNO approval for a greater export and install a second inverter. Being Victron, they would communicate through the GX device ( mines a CCGX) which controls everything and allows control of everything most importantly the times you want to charge from the grid. My Pylontech s are limited by my inverter, charging at 3.7kW/h which means that I can't get the 95% of 16kW for all 5 batteries in 4 hours, ( I can only get 15kW) but I rarely need it as the solar tends to top them up during the day at the moment. The second inverter will cure that problem and allow for a further 2 batteries.
By my calculation, this would allow me to run at the cheap Go rate from February to November but at todays prices would only break even in year7-8. There wouldn't have to be a big increase in price for that to be brought down into years6-7 which I would consider acceptable.
Thanks all, very useful information to inform my discussions with installers. At least I have a clearer idea of the key questions to ask now. There are clearly additional complications with two batteries/two inverters and how to control that so I may also revisit the larger capacity single Powerwall proposals. Biggest challenge at the moment is getting the recommended installers to reply!
Forgive the newbie question, and sorry if I should start another thread instead of asking here. How worthwhile is a powerwall/battery without solar, i.e I have Go Faster with 4 hour window at cheap rate, it is possible to charge the car and battery at the cheap rate and then use the battery to power the house for the other 20 hours or until its empty? Or would it be too much load to draw at once? We use around 10Kwh at home per day if we do not charge the car. We are way up in North Scotland so I don't know if solar is worthwhile in our case.
Yes - if you have something like octopus go at 7.5p/kwh you can aim to move 90-95% of your home usage to that rate rather than 31p peak rate (saving 23.5p/kwh) or perhaps 40-45p/kwh in October (saving 32p/kwh or more).
10kwh/day thats a saving right now of £857 a year, going up to £1200 a year at 40+p/kwh. Solar will help even more of course
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