Solar panel battery

samstheman

I've now had solar panels for five years and so far the money returned from the grid has covered the cost of my electricity bills. I was considering having a battery fitted to conserve lost electricity but at a cost of £1,600 or more I don't know if its worth it. We are now both retired and therefore using more electricity during the day. Does anyone have any thoughts on this please?

[Deleted User]

This is probably not the right forum to ask such a detailed/technical question. Try Navitron.org.uk.
You need to think carefully about the type and capacity of battery that you choose. For example, do you want it to export during peak periods or just store your some of surplus electricity? I ask because of Octopus' Agile customers have been receiving in excess of £1.50/kWh for the energy that they export (clearly, at the moment this is after the sun has gone down).

I have a Tesla Powerwall 2 connected to my solar array. It has 13.5kWs of usable capacity. The slight downside is that unless it is under Tesla's control, I cannot export from it but, that said, I am effectively off grid from late February until late October. I recharge the Powerwall overnight at 5p/kWh.

Finally, if you are over 60, you should be able to purchase a battery at 5% VAT.

Cardew

There is also masses of information on the Green and Ethical section of this forum.

ASavvyBuyer

As above, take a look at https://forums.moneysavingexpert.com/categories/green-ethical-moneysaving where there are a number of topics, with people that either already have batteries or are considering them.

Regarding the 5% VAT rate, that only applies if installing Solar PV & a battery at the same time (if you are over 60). It does not apply if just installing a battery. The normal 20% rate applies.

Therefore, it is worth considering getting some extra PV panels installed at the same time.

Richmc

I had batteries installed five years ago, really happy, It's a lead acid based system and as I get deemed export payment on 50% of generation most of the year it's more like 5% over winter zero and I think it's saving me another 30% on energy bills over what the panels are saving, I only use 3000kWh per year from the grid. Tesla systems were very expensive at the time so lithium ion wasn't an option, one bonus is lead acid batteries one worn out can be sold to your local scrap dealer, lithium ion can't as recycling is a complex and costly process, so when I need to replace them I should get a nice bonus back. Have a look at rudgeenergy web site I have a Vectron inverter system.

Petriix

It's incredibly unlikely that a battery could save you any money in its usable lifetime. Even if it could halve your bill, you'd be looking at a 15 year ROI for something with diminishing capacity and only expected to be usable for 10 years.

Ectophile

If your current inverter is working fine, and isn't designed to use a battery, then it's unlikely to make any financial sense. $1600 buys you an awful lot of electricity.

I was persuaded to get a small battery (3kWh usable capacity),  when my original inverter failed and needed replacing.  You can feel very smug running off free solar power at 10.00pm when everybody else is paying for theirs.  But in the depths of winter, when grey days are common, a battery can seem pretty pointless.  There are days when the solar barely covers the base load in the house, with nothing left over to charge the battery.