FabSwingers.com forum: Solar batteries

By *ackdaw52 OP Man
over a year ago

Chesterfield

Is anyone using or researching household batteries? I need some opinions.

I've had several quotes each giving different prices and advice.

It will be primarily for storing electricity generated by solar panels, and occasionally being set to charge overnight to utilise cheap rate electricity.

Initially I wanted to get the biggest battery I could afford, my logic being more storage equals more savings. And also with one of the larger ones I could store maybe two or more days energy if we have a sunny day followed by several cloudy ones.

However, one contractor told me it was false economy to have a battery larger than one days' use. He seemed to know what he was talking about but I don't understand this.

Also, some contractors advertise batteries as providing backup power in a power cut, but others say this is not possible?

Advice and opinions, please!

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By *rHotNottsMan
over a year ago

Dubai & Nottingham

Are you on feed on tariff to supply the grid or keep your own for your own use

can’t advise at all about domestic use but we are mdoing huge R&D in Africa as part of the solution to reduce diesel and DC generators. All I can say is it’s a good 5-10 years away unfortunately , the tech storage will likely go through many iterations and a few big jumps depending on which companies invest but when it comes it will be a game changer for industry, electric cars , off grid rural , and new build homes.

If I was looking to put storage into my home I’d do simple ROI calculation which would prob tell me buy the 2nd or 3rd latest tech second hand rather than the latest , store for one day and sell the rest , unless there’s a clear buy back / replace scheme.

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By *rHotNottsMan
over a year ago

Dubai & Nottingham

I’m guessing the false economy is that to store more than 1 day you need to invest higher amount of capital , then the ROI over life of the solution and units stored means cost per each unit is more than the cost of buying from the grid? But check this, ask to see the ROI calculation on 2-3 different devices at different levels of capital.

Remember to factor in 13% inflation and 2-3% interest loss on any capital because you could put the same capital somewhere else

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By *hristopherd999Man
over a year ago

Brentwood

It would most probably take ten years before you made a profit

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By *ackdaw52 OP Man
over a year ago

Chesterfield

I see, yes that makes sense.

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By *ackdaw52 OP Man
over a year ago

Chesterfield

Payback time averages about ten years, because I am a low user.

But I could put the same amount of money into buying gas and get nothing back!

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By *ovebjsMan
over a year ago

Bristol

"It would most probably take ten years before you made a profit"

Just before the battery is knackered

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By *rHotNottsMan
over a year ago

Dubai & Nottingham

"Payback time averages about ten years, because I am a low user.

But I could put the same amount of money into buying gas and get nothing back!"

Payback is one thing. In any investments there’s payback time , then return on investment (ROI) after payback . With tech you need fast payback because the value of tech halves every 18 months (Moore’s universal Law). Chances are far before 10 years , you would chuck the solution away , for a better cheaper one , it probably wouldn’t even last 10 years tbh.

You could put the same money into gas and get nothing yes. But you could put the sane money into many other better investments for 10 years and make a huge profit

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By *exi_LexiTV/TS
over a year ago

caerphilly

I'd just do it like campervan setup with 12v gel batterys off 12v panels, run one or two inverters off the batterys and use that power for all the low wattage stuff and charging your daily items, u will still need to run oven, washing machine, kettle etc from the national grid, but will save you on about half your monthly bill, and not to expensive to buy and easy to install

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By *ackdaw52 OP Man
over a year ago

Chesterfield

Investments like what?

Are you saying everybody should buy Bitcoin instead of renewable energy?

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By *annaBeStrongMan
over a year ago

wokingham

"Investments like what?

Are you saying everybody should buy Bitcoin instead of renewable energy?"

Lots of investments out there that can get you 4-7% return almost guaranteed

I think he’s saying if you want return, invest in other things

If you want to be green, get solar, but don’t ever expect to get a return because by the time your close you’ll need to update it all

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By *ndreaNWCDTV/TS
over a year ago

Kirkham

My experience after installing solar and batteries 12 months ago…:-

I have 10kw of solar panels (40 panels) and 6kWh of high voltage lithium batteries, the batteries are uually charged by noon In summer on a sunny day they can be charged by 10.30am… in winter it can be 4pm, and on a bad day they won’t make 100%.charge at all

We have 2 households running off the system, my house and a granny flat… our average use is 1500 kWh per month, so at current price about £5500 a year.

The solar has knocked that down to £2000 over the past 12 months. Plus I’ve sold about £350 of electricity back to the grid, as well as saving probably £500 in heating oil by heating water from the solar power, instead of using the boiler…So a saving of at least £3500 in the year.

Cost of installation was £14000, so break even in 4-5 years.. sooner if energy prices go up as expected… panels are warrantied for 20 years, batteries and inverters for 10 years. Replacing the inverters and batteries will cost about £5000…

I think it’s been worthwhile, but time will tell…!!!!

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By *icecouple561Couple
Forum Mod
over a year ago

East Sussex

Following

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By *ellhungvweMan
over a year ago

Cheltenham

"My experience after installing solar and batteries 12 months ago…:-

We have 2 households running off the system, my house and a granny flat… our average use is 1500 kWh per month, so at current price about £5500 a year.

I think it’s been worthwhile, but time will tell…!!!!"

This is a good summary/analysis. Thanks for the insight.

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By *ackdaw52 OP Man
over a year ago

Chesterfield

"My experience after installing solar and batteries 12 months ago…:-

We have 2 households running off the system, my house and a granny flat… our average use is 1500 kWh per month, so at current price about £5500 a year.

I think it’s been worthwhile, but time will tell…!!!!"

Payback time will vary depending on how much energy you use plus what set up you have...and energy prices of course!

Do you find that a useful battery size or would you prefer more storage?

I realise you are selling off any excess but using energy you generate yourself is many times more cost effective than selling it.

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