£/KWh Recommendation for battery > 8KW with > = 90% DOD

abeezar

Hi
In the process of choosing a battery to store electricity at a cheaper rate and use during the day ( avoiding peak 4 pm - 7 pm).
After reading several posts/forums still undecided. Ideally would like to have storage up to 16KW, with a peak output of 5KW, 10 Year Warranty.
I would like to have recommendations on the basis of £/KWh considering a  DOD of 90% minimum and considering degradation in 10 Years' time.
Regards

AntonyTewks

At that size , output and warranty I would think Powerwall. I don't think the battery market is anywhere near maturity yet so prices are still high for the payback

Solarchaser

I'd opt for lux parallel inverters and pylontech batteries, after doing A LOT of research over a few years, thats what I went for around 2 years ago. (Well originally picked up a sofar inverter, but switched to lux about 10 months ago)

Unfortunately the price of the batteries has not declined as predicted by so many, and so with 90%dod a pylontech 2.4kwh is still close to £400/kwh so you are really looking at say 8 batts at around £6.5k plus inverters brings you to around £8k
And you are gonna struggle to save £800/year in electricity to justify your purchase with 10 year roi. 

With a powerwall its about £10k for 13kwh, so it's a worse deal again.

Now if you can pick up batteries cheaper, then cool.
I got 5 of my 8 batteries second hand and so saved some money,  but I'm still about a 12-13 year roi.

Petriix

Buying a battery won't save you any money unless you are a very high user, although I am yet to see any real world examples of *anyone* coming close to breaking even within the warranty period of any battery system.

A simple sense check is to multiply your current annual electricity bill by 5. Assuming that a battery could halve your bill then, in 10 years, that would be your total saving. If you can get a suitably sized battery installed for less than that figure then the investment will be worth it. For me that figure would be around £3800.

I suspect that you would be better off withdrawing £1000 in cash and flushing it down the toilet and not buying a battery. However, the Pylontechs seem to be the best value at the moment, and batteries *might* keep working for 20 years and retain some useful capacity.

EricMears

abeezar said:

Hi
In the process of choosing a battery to store electricity at a cheaper rate and use during the day ( avoiding peak 4 pm - 7 pm).
After reading several posts/forums still undecided. Ideally would like to have storage up to 16KW(h !), with a peak output of 5KW, 10 Year Warranty.
I would like to have recommendations on the basis of £/KWh considering a  DOD of 90% minimum and considering degradation in 10 Years' time.
Regards

If you're only bothered about avoiding 4-7pm usage (Octopus Agile I presume) you probably wouldn't need anything like as much as 16kWh.  Simply by avoiding heavy users and turning off fridges in that period we've got our consumption below 0.5kW for that period so could make do with a 2kWh.  But looking at it again,  1.5kWh at (up to) 35ppu was only going to cost me around 50p per afternoon or less than (say)30p more than it would have cost on another tariff.  30p/day is only around £100/year  and I'm really not confident of finding even a 2kWh storage system for below the £1000 it would need to be for a 10year 'payback'

Petriix

Another really important factor is that Agile (and Go et al) is a beta tariff that is essentially being offered on an experimental basis. I wouldn't use it as the basis for making a multi-£thousand investment with an intended ROI of a decade when there's no guarantee it will still be available in one year let alone 10.