Solar panels - how important is the battery?

[thebellagio]

Not an AIBU but posting for traffic

ive been looking into solar panels for my house as I’m terrified of the rising energy prices. Last week I was quoted £11.5k for 24 panels plus the inverter, battery and bird cage around the panels. This seems high and he confirmed that it would take 10+ years to break even.

im currently undecided what to do - that’s such a frickin huge outlay and would basically take all our savings. But on the other hand, I feel like it would reduce our bill and potentially add value to the house which we will be staying in for at least 10-15 years.

I guess what I want to know, is if you have solar panels how essential is it to have the battery as well? I completely get it means in the evening you’re working from the solar power you’ve generated rather than buying from the grid but broken down, the panels are about £6k and the battery is £5k so I’m trying to work out if I could save here…

we use about 6kwh electricity a day according to my smart meter. I’ve been quoted for a 4.2kwh system but a 9.5kwh battery so I’m reluctant to spend that amount of money on a battery if we’re only going to use a minimal amount of the solar power generated. At the moment we don’t have electric cars, so our solar usage is unlikely to change for at least 3-4 years

Has anyone got any advice?

if the primary energy use you do is during the day, then the battery isn’t essential.

Your energy usage is very low, tbh. 6 kWh/per day, even if the tariffs rise to 50p average is still only £1000 per year ish.

batteries only really make sense for high usage families who have high nighttime costs, imho.

Tbh - with such low current usage I’d question from a financial standpoint even bothering with solar.

You’re probably doing most of your use at night, so without the battery it’ll not be used and fed into the grid.

I have no idea about current feed in tariffs, maybe you could make some money there.

battery and solar tech is likely to come down in price. If your energy consumption increases, it might be worth it then.

We've just ordered panels without a battery. The panels will take 8 years to cover costs, the panels plus battery was 10+ years to pay back.

But the decider was that the batteries we were offered would need replacing after 10 years anyway, and we'd only really be using them for power cuts, so we are going to review it and see if we can add some later when they are more efficient if we need them depending on our use once we have the panels.

Get more quotes - we got 3 very different ones, best overall was e.on - not the cheapest but the best value.

The battery is the game changer. We charge ours off the sun during the day, power everything off the sun (if it’s sunny), feed a bunch back into the grid, and discharge it making dinner, then charge it from off-peak cheaper power at night and discharge it making breakfast.

It’s the bird cage I’d delete, don’t really see the point in that unless it never rains where you are. We have loads of pigeons but the rail always rinses any dirt of the panels.

I don’t think the Op is using nearly enough energy to justify the battery though.

relatives discovered the battery is essential.

there was a power outage in a village and despite having high output solar panels, they couldn't use their solar electricity because they opted for the less expensive option without battery and re-feed loop.

That doesn’t make it essential - that makes it a ‘very nice to have’. The rest of the village presumably didn’t die during the brief power outage.

We're adding an extra battery because during the winter we'll be able to charge them overnight cheaply and we have teenagers so there's lots of evening use.

Batteries cannot be used in power cuts unless you have an off grid set up which requires specialist installation and permission from the DNO. It’s a common misconception. They do allow you to store your electricity and use it at night.

we have a 9kw system going in next week with an 8kw battery. Because of the size of it we are only allowed to export to the grid at the equivalent of the inverter cap (3.68kw). This is because the cabling etc to the property needs to be changed if you export any more than that (in most cases).

the tarrif (seg) is very low for selling back your electricity. It varies between suppliers but most pay about 4p

our set up allows us to run a large house with two of us running businesses from home, run an everhot (electric storage range) and potentially charge two EVs. We then have a battery for evening use and a solar immersion Element so that any excess heats our water. This should enable us to maximise everything we generate. We don’t want to be selling back to the grid at those prices (and then buying in the evenings when there is no light at 27p (rising significantly in the autumn).

our application was delayed for various reasons. Between our quote last year and the vat then being slashed the price of the panels and installation actually rose significantly rather than falling and so I wouldn’t expect prices to be falling any time soon. Demand is high.

We had panels and battery installed recently and at the time ours seemed very competitively priced, and yours fails into that price range, but you're getting 3 times the panels we bought. Our 4k battery stores enough for us to run the few things we run overnight. We expect the battery to be redundant in winter months but we've yet to experience that.

24 panels? I thought the max for a domestic dwelling was 16 but that might have changed since we got ours done. We had ours installed 3 years ago, 4.5KW system for £5500 and that included ground mounting at the end of our very long garden (due to funny shaped roof) and running trunking under the ground back up to the inverter in the garage.

2 years ago we added a battery to the system for £3000. It's a Pylontech Li-Ion Battery 3.5kW. In summer it powers our evening usage including cooking. We tend to do laundry and dishwashing during the day though.

To me it's worth getting as much usage out of your generated power as possible now as the FIT rate is crap, so don't waste it putting back into the grid.

It’s about the kw value not the number of panels. Panels vary in the amount they generate. Ours are optimize panels which cost more but deal with partial shading

Is no one else reading the energy usage of the OP? The whole idea barely makes any financial sense.

From an eco standpoint - yep. But this is one area of tech that’s very likely to be coming down in price in the coming years, so given their usage it really isn’t a situation to panic.

We have solar panels and a battery panels bought about 8 years ago and now paid off, battery bought a couple of years ago. A few months ago we bought a new washing machine and a heat pump tumble dryer, both A/A+ rated. We find that if we use them on a bright (not necessarily sunny) day we don't need to use any electricity from the grid at all - and that has been the game changer for us. The downside is that the tumble dryer seems to take about 3 times as long as a normal one - but as it's not costing anything for us to use that's not normally a problem. We have a battery but it is much smaller than the one you have been quoted for and I wish we had got a bigger one. We do also have a thing that diverts any unused solar power into heating our water (we are all electric) so we are really making maximum use of our solar power.
So - if you can afford it I would go with the solar panels and battery plus A+ rated appliances. The combination should leave you with considerably lower electricity costs.

We have solar panels and don't have a battery. As others have said, most of our usage is in the day anyway. On the other hand a neighbour has just had them installed with a battery because his plan is to then charge his electric car from the battery over night. So it depends on your usage plan really.

We also got paid £300 back from the energy company for the energy from them over the last 3 months.

We're making a similar decision op. We're not on any Economy tariff at the moment as we don't have the right meter - is it worth switching to one if we get panels and a battery? I've tried to research them but there's nowhere to compare Economy tariffs. I've been told the energy companies want ppl to use night rates as they want to avoid overloaidng the grid with everyone using it at the same times, so encouraging spreading the demand.

@SquigglePigs my friend said if you have an electric car you can use the battery from that?!

We are battling with whether or not to get a battery. It's such a huge outlay.

We have 20 panels, the reality of this is we can generate up to 3kw an hour and as long as our usage is no more than 2-3 kw an hour it's free.

I put appliances on back to back but not at the same time as the e very consumption exceeds what we produce.

I can use the washing machine, dish washer and dryer all for free between the hours of 8am and 2pm summer and 9.30 am to 2pm winter. Obviously this is also dependent on a sunny day.

We have an app that connects to our panel receiving the solar energy so I can see when we are generating and how much I'm using in real time.

As I'm at home during the day and I can make best use of the energy we generate, we can't justify the outlay for a battery. I'm already using 2/3rds so we'd be storing 1/3.

The recent price hikes have made me very aware of ensuring I use the energy we produce before using bought in energy. It's definitely helped.

Also definitely have the bird cage installed. We had pigeons nesting under ours and they are soooooooooo noisy!

If you want seg payments for the electricity you generate you will need in most cases to be on their seg tariff. Otherwise you will just feed your excess into the grid for free

The battery is incredibly important. You want a Lithium Iron Phosphate one, which has thousands of life cycles.

Setting up solar doesn't have to be expensive. I just bought my first portable kit and you can even get expandable kits now.

May be look into wind and solar owing to British weather?

For those who can’t afford a battery, if you have an immersion tank the best way to maximise your use is to use an iboost (or similar system). That will give you free hot water for low installation cost (about £700 for the kit and installation)

PS. Is your kWh usage an average for the year?
Is it likely to increase in the winter?
Are you planning to run more electric instead of gas to keep warm?

Things may settle in 2023 (apparently).

I'd love to get solar panels we have 3 south/ south west facing roofs and a garage

No idea where to start! Any recommendations?

That was an unfortunate typo in my first post - its 14 panels, not 24 panels! Sorry!

I've just looked at my energy statements

According to the smart meter my electricity usage over the past few weeks has been 52KWH / 54KWH / 55KWH so fairly consistent. We have a combi boiler, so it may go up slightly over winter when the heating comes on but otherwise, our patterns will be the same.

The bird cage is an essential. My husband is a window cleaner, and he says the amount of literal shit that goes onto the ones without the bird cage is insane.

I just can't work out whether it makes financial sense to go with it or not.