9.5kw batteries without solar panels 14 February at 12:42PM in In my home (includes DIY) MoneySaving 10 replies 503 views

GuidanceNeeded

Hi all, my roof is quite shaded and as a result I was wondering how cost affective it is to purchase 2 x 9.5kw batteries and store up energy at night.
What are the best companies that include installations and what kind of prices are we talking about ?
I am in Harrow, London
Thanks

grumbler

I'm no expert, but if it's for heating then storage heaters have to be more cost-effective.
Otherwise, do you really need 19kW of power? Or is it 2 x 9.5kWh?

CliveOfIndia

Are you intending to just charge up the batteries at night from the mains?  If that's the case, do you have E7 or other off-peak cheap-rate tariff available?  If not, then you'll gain nothing.  Even if you do have access to E7, it's going to take quite a while to recoup the initial purchase cost.

FFHillbilly

check you can get a good tariff first. I know someone who had a 12kW battery fitted in 2021 and used to charge it every night and it would last all day, and as soon as the energy market went mad last year the prices have gone to the same as peak rates. I suggested getting on the octopus intelligent tariff but apparently you need an EV for that (and they check)

markin

You need some solar to save the 20% Vat, micro inverters or optimises help with shading.

Batteries have an average of 16 year payback, even poor performing solar would probably still payback faster.


Spend a day reading threads over on the green sub forum. https://forums.moneysavingexpert.com/categories/green-ethical-moneysaving

GuidanceNeeded

Thanks for the responses

Dolor

A few things to factor in:

Battery losses - most batteries have a c.10% round trip loss.

VAT - batteries attract 20% VAT whereas solar and a battery do not.

Your import cost compared to what you actually save. There are more tariffs available for solar and batteries than just a battery.

GuidanceNeeded

for some reason, companies seem to have little interest, they simply do not even contact back !

markin

They are swamped with customers, If you can find one the will probably be months waiting lists for the install.

ComicGeek

Unless you have an electric car and are on a really low night time tariff like Octopus Go, don't bother. You're probably looking at around £12k for a battery installation of that size.

19 kW of batteries will give you about 14 kW of usable storage - if you're lucky and charging that at 7.5 p/kWh each night (and you're using enough electricity to drain the batteries every day), then you might be able to save about £5/day, and get a payback in 7 years. However, if you can't get those rates, or if the rates change, or if your actual usage is less, then the payback period starts increasing beyond the life of the batteries.

To be honest, most installers won't think you're serious without PV as well, and will think it's a waste of their time to quote. It took me 10 months from quote to installation of our battery system, I know some people have been waiting for a year now.

_Sam_

Is a 'company' necessary, could you not just buy the batteries you want, and arrange a local electrician to wire them in?