Solar Battery - Where to start?

[Geordie Spock]

Hi

I have just joined the forum and looking forward to being part of the group.

We were really fortunate to have 10 solar panels fitted free to our property last year under the Green Deal, and we re now thinking of adding a battery to use when the sun doesn't shine. The panels can generate 3.1Kw of energy.

We have no idea where to start and would really appreciate any advice.

TIA

 

[Mrjmegson]

Start by working out how much energy you use a day, and when you use it. So e.g 10kwh a day, 7kwh in the evening, 3kwh during the day.

Use this as the minimum size battery you want, so around 10kwh in this example.

Then think about if you would like more capacity, to get you through x number of days of bad weather, if you're not on a time of use tariff where you can charge the batteries cheaply in the evening.

If you are on a tou tariff, then I'd say you only need a battery big enough to cope with your daily demand.

You also need to forward plan, are you going to buy air source heating in the future, or similar, so may increase your daily consumption.

As far as the actual battery, you need to either look at your inverter manual, or speak to the supplier to find out what batteries are compatible with your inverter.

Do you have a hybrid inverter, one that controls solar, battery charge/discharge, and powering your house? I'd guess not if it was free. So you will probably need additional equipment to charge the batteries.

Hope this helps and I haven't made it sound too daunting.

Jay

 

[Geordie Spock]

Thanks Jay for the reply.

We live in a 2 bed bungalow and there are only us 2 who live in it. I'll have to check what type of inverter we have.

Once again many thanks

 

[Geordie Spock]

This is what we have installed in the loft

 

[Mrjmegson]

I've just put Solis S6 into Google, and a few versions come up, but they all appear to just be string inverters, so they don't deal with batteries.

So unfortunately you'll also need a separate piece of kit to charge any batteries you get.

It might be worth looking at replacing the inverter with a Hybrid that does it all, but that obviously takes away from your budget.

 

[johnb2713]

Leace the existing kit as is and install an AC coupled battery.

 

[Mrjmegson]

What equipment do you need for an AC coupled battery?

 

[johnb2713]

inverter + battery

 

[Geordie Spock]

Thanks for the reply guys, I'm not sure if it will be worth doing, especially since I'm not clued up on the equipment I would need.

 

[johnb2713]

Thanks for the reply guys, I'm not sure if it will be worth doing, especially since I'm not clued up on the equipment I would need.

You can achieve quite good returns making the break even point fairly short. Have a look at Fogstar for batteries and somewhere like Its or Amazon even for a suitable inverter, look for a 'hybrid' inverter and then you get a sparkie to install a mains feed to the inverter, plug the battery and press the button. Actually you do also need to talk to your DNO also with details of what youre proposing.

 

[Geordie Spock]

Thanks Johnb2713, what is a DNO?

 

[johnb2713]

Thanks Johnb2713, what is a DNO?

District Network Operator, I'm guessing where you are that will be Northern Powergrid.

 

[bladerunnerpv]

If you go the AC coupled route for batteries then here's a couple of options to start exploring

https://midsummerwholesale.co.uk/buy/giv-energy/giv-ac-3-5200-g2batt-kit
https://midsummerwholesale.co.uk/buy/solax/solax-x1-ac-36-30-bat-bundle
Not saying these are best options, just possibles.

Try googling deegesolar and spiritenergy to read up on AC coupled and DC coupled, some useful blogs there

Ideally have a look at PVGIS or Easy-PV to get an idea of how much of you PV output is being exported and so could be stored, then start thinking about sizing batteries. Also you can charge the batteries on Economy 7 or various other tariffs overnight / when there's no solar.

It's possible you might need additional consumer unit, depends on what's there already.

 

[Geordie Spock]

Thanks guys for the advice, it's really appreciated