Are batteries worth it for me? 1000kw per month usage

ABrass

Grandad2b said:

I hope I'm not about to take this thread off topic - I keep seeing certain inverter/battery pairings being mentioned - are there batteries that have to be used with certain inverters or vice-versa or is it more a question of installers being tied to particular brands?

Yes.

In short: it's a mess and you'll need to check each inverter to know what it is and isn't compatible with.

Most batteries have a level of Management software (BMS). They're designed to manage their own internal performance and talk to an inverter which tells them what to do, but not the details on how to do it.

Some inverters require their own bespoke BMS to work as the inverter wants to interfere a lot, others have an interface that a third party battery can understand to allow them to be used. Some will allow you to use any batteries as black boxes and operate with virtually no insight into the internal performance.

Back on topic: Battery price matters. Have you taken into account the need for G99 approval for these batteries and/or replacing your existing inverter with a hybrid?

anon_ymous

EcoScruples said:

Krakkkers said:

Biggest saving would be using less, is this possible to look at first?

The most cost effective way to save electric, nothing comes close.

This. I'd look to see exactly what's using that energy perhaps using an IHD at the very least, where you can't use a watt meter. Watt meters would be better, especially if they're smart ones like the TP Link ones which allow you to see that information "in a single pane of glass", to use the typical marketing term. 

Mikeyboy01443

smart_taunton_bloke said:

Looking for some advice about batteries. Hope someone can help?

We use about 1000kw a month. No gas. 

In March we used:

350kw daytime at 51pence - cost £178.50
625kw nighttime at 12.3pence - cost £76.80

If I got batteries could I have moved the daytime to nighttime, are these figures correct? 

Cost daytime - £178.50
Moving that to nighttime 350 x 12.3 pence £43.05
Saving - £178.50 - £43.05 = £135.45

We also have 14 solar panels that would help top up during the day. 

I'm looking at a Lux inverter and battery system that would £5,300 installed - 7.2kw. 

Am I thinking along the right lines here or am I missing something?!

Thank you

Is that 1kw every month? I use close to that in winter but less in the spring summer months i think...

smart_taunton_bloke

Thanks everyone for your help. 

We aren't using anything excessively, so no hot tubs or anything. The house has 2 adults and 1 child under 10 here full-time. And 2 older teenagers here half the time. 

We use storage heaters - which I think use some daytime electricity in the evenings if they have not stored enough energy. 

We also use off-peak to heat the water. And the washing machine / dishwasher go on overnight on the off peak. 

Last June our usage was 160 daytime, 150 nighttime. 

@Mikeyboy01443, @Petriix, @Screwdriva - here is a bit more context, thanks for your help. 

smart_taunton_bloke

Alnat1 said:

If you are looking at Lux inverters, consider pylontech batteries. If you find you need more storage you can easily buy them online and self-install with just a couple of cables. Two US5000 (4.8kw x 2) might be a good starting point.

Thank you @Alnat1 -

we are looking at these packages, them seem to be be the best value and the company have good reviews:

https://lr-renewables.co.uk/product/lux-7-2kw-battery-storage-bundle-installation-included/

https://lr-renewables.co.uk/product/lux-7-2kw-uhome-battery-storage-bundle-installation-included-copy/

Reed_Richards

smart_taunton_bloke said:

We use storage heaters - which I think use some daytime electricity in the evenings if they have not stored enough energy. 

You should try to monitor how much daytime electricity your storage heaters use.  If it's more than, say, 20% of what you use at night then it's a significant part of your total heating costs.  If that were the case it might be worth considering alternative forms of heating.  There's an Air Source Heat Pump (air-to-water) if you don't want to burn fossil fuels.  Or oil or lpg if you don't mind.  These options would require your house to be plumbed with radiators.  Or you could use an air-to-air heat pump to supplement your heating; that would be most energy-efficient in spring and autumn.    

andyg9053

You need to look at each month’s figures. Possibly consider Dec Jan and Feb not being totally covered by the battery,  as you won’t have much solar generation. But the extra cost of a larger battery just to cover those months may not justify the larger battery. 

smart_taunton_bloke

andyg9053 said:

You need to look at each month’s figures. Possibly consider Dec Jan and Feb not being totally covered by the battery,  as you won’t have much solar generation. But the extra cost of a larger battery just to cover those months may not justify the larger battery. 

Thanks @andy9053 - yes thats what I was thinking about not having capacity in those months. I think starting with the 7.2kw and see what happens next winter seems a good option.

Krakkkers

If you are using 310 kwh in June when you have solar panels then something is not quite right.
Do you not make use of the generation to heat water and do other things or are you charging an EV?

Screwdriva

Reed_Richards said:

There's an Air Source Heat Pump (air-to-water) if you don't want to burn fossil fuels.  

Agree with Reed - A heat pump installed correctly would make sense as it will dramatically improve efficiency if the household isn't poorly insulated.