Not sure if I am allowed to tell about this but it's so amazing

[TheEponymousGrub]

Sorry for the crappy clickbaity title but this might be considered advertising so it could be pulled. We shall see, but in the meantime:

We recently got solar panels and they mentioned that even if you aren't getting panels, it's really worth getting the BATTERY installed, and changing to Economy 7 supply. Then, you charge the battery overnight at discount rate, and use it in the daytime, instead of buying power at full price.

Our battery cost £1200. Economy 7 power is 12p/unit at night whereas "normal" supply is 24p/unit (those prices are from SSE Airtricity today) so if your bill was £100/month, you'd save half of that and recoup the cost of the battery in 24 months. After that, your power is half price.

The lady who told me this knew I was after panels so this wasn't especially relevant to me, but I think she just wanted to tell everyone. I can understand that and here I am sharing it here!

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Updated by MNHQ
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How big are the batteries for £1.2k (I.E. how much do they store and how much do you use per day?)

They put in two 3.6kWh batteries in a glass cabinet that could hold four. We've only had them a few weeks. They charge fully before lunchtime, and seem to meet about 80% of our power needs, but we have a big house (and bad habits that we are now all about addressing!)

So I'm thinking, maybe we could usefully have bought more battery capacity? But maybe it's too soon to tell, since it's only been summer so far.

That's really useful info to look into OP, thanks!

I have economy 7 but it can only be used for my storage heaters and all of the plug in appliances like the washing machine are on a different circuit or something so that I can't use cheap rate for them. Would it be the same for a battery?

Hmm. I want to write "It must, or else what's the point?" But the truth is, I don't know ANYTHING more than what I have posted! But the lady at the solar panel company, who told me about this, indicated that the battery would take the night-time supply like a storage heater, and then release it like a battery (as it's supposed to). I imagine the people installing it would be able to confirm/explain about this.

Which company are you using OP? Are they National?

I have economy 7 but it can only be used for my storage heaters and all of the plug in appliances like the washing machine are on a different circuit or something so that I can't use cheap rate for them

I too have economy 7 and the storage heaters are wired in, but the economy 7 applies to all electricity in the house. I know this as fact because we have 2 connected electricity meters and at 12.30am it switches over from the daytime to the nightime meter. Likewise back again at 7.30am. All units clocked up on night meter are cheap rate. I can see it clocking up when the kettle, washing machine or anything else is switched on. The daytime one stops dead when the night rate meter starts.

Oh yes and more importantly, the immersion water heater. That uses lots

Where did you buy your batteries from op?

We have solar panels and would love a battery so we can charge it with the panels in the day and use that for the underfloor in the evening. Could they be used for that? What company did you use? Lat time we looked the batteries were ££££

Check that getting a cheaper night rate with your energy supplier doesn't give you a pricier day rate. I think (might be wrong) not everyone can get Economy 7?

A cheap night rate almost certainly means a more expensive day rate. However, if you are able to store energy during the night when it's cheaper (using batteries like OP) and then use the batteries as power during the day, you can save a significant amount as you then aren't using electricity during the more expensive day rate. As well as E7 there are day/night rates that are aimed at electric vehicle users that have shorter, even cheaper blocks (so instead of 12 hours or whatever at 16p you might have 6 hours at 10p).

To the PP on E7, definitely check that's correct. Usually E7 tariffs apply to all electricity used between the time period. Your storage heaters will be wired in so that they only heat up when the E7 tariff clicks over (daylight savings etc. can change this so it makes sense for it to be wired in rather than running off a timer all the time), but it's entirely likely that any other electricity you use this time will be at the cheaper rate too.

Are you absolutely sure? That's not normally how it works.

I'm on E7, and yes, there's a seperate circuit for the heaters, that's only live at night so they can't use any day rate electric. But once the night rate kicks in all the electricity in the house is charged at the lower rate.

That's been the case in every E7 house I've lived in.

Second request for what company you used OP? Very interested in the idea of using batteries with E7!

@Paulapeake I am another one asking are you sure because I used to work for an electricity company that covered a lot of rural areas and so lots of customers with econ 7 and no gas. They all use to listen for the click to know when the meter turned onto the night rate so they knew what to set their plug in timers to for their washing machines and dishwashers etc.

Every one had a slightly different turn over time due to storage heaters turning on to heat up and the demand that placed on the grid, hence the slight time differences. Now with more modern meters there is usually no more separate night time meter, the readings I believe are just contained within one meter.

Always worth looking at the day rate for any company that offers a cheaper night tariff and running a comparison. There are great little plug in electricity monitors, we use Tapo, and can see on the app how much certain appliances are using. That way you can work out what you will use at night, using the batteries in the day to save on the more expensive rates is brilliant.

@TheEponymousGrub which solar company did you use?

We were getting solar panels installed and the battery was an optional part of that set-up.

We are in Northern Ireland. This info came from a company who quoted me for solar panels, but we didn't get our panels from them in the end.

That's insanely cheap for batteries.

We got our battery, a Dyness brand one, from a company called BlueBuild - but BlueBuild are in NI. They might do an install in Britain though...I guess if the price is higher it would take longer to recoup the cost of the battery, is all.

Well it would give you a pricier day rate but you'd aim to barely use that at all. You could be right about the availability of E7, I don't know that at all.

Surely you need the panels to charge the battery don't you?

Oh.... I made a mistake. That was the cost of a different component of our solar panel installation😳

The battery was £4750 inc. VAT. So, it would take nearly 8 years to pay off - well, it will be quicker if/when the cost of electricity goes up.

oops

But still! Solar panels take far longer than 8y to pay for themselves, and they are a far greater outlay. Plus, if you have the battery, then installing panels later becomes both cheaper and more worthwhile.

But, oops. Do I have to change my name in shame?

No, that's the point. You charge it with cheap grid power at night and discharge it in the daytime instead of buying the pricy daytime power.

But, oops. Do I have to change my name in shame?

I would :)