Batteries are they worth it...

Guru861

Hi, I am trying to get quotes for solar panels. So far only one company has responded.

They have quoted with a battery and one without. The system with the battery is roughly 10k and the one without is roughly 6k.

Is the extra for a battery worth it?

We spend a lot of time at home during the day at the moment due to working from home.

Thank you

QrizB

If the goal is to minimise your use of grid electricity, batteries are a useful addition to solar PV. With an appropriately-sized array and battery you can be essentially grid-independent for 6-8 months of the year.

Financially, the case makes less sense (unless you expect electricity to continue to cost 28p/kWh for the next decade).

JKenH

The problem with any technology is that it usually gets cheaper over time. That trend however has recently reversed with solar panels and might with batteries. It’s hard to predict the  future but batteries make more sense now than a year ago because electricity prices have risen.

You need to bear in mind that what you save into your battery is electricity you won’t be exporting so you will lose out on SEG. If you are getting 5p/kWh export, it is effectively costing you around 6p if it goes in your battery because of round trip losses. You might though save 24p/kWh (30p cost from grid less 6p).

arty688

A lot also depends how much electricity you use. Me for example use around 20000kwh per year. So most days I would be charging the battery overnight and discharge before the solar kicks in saving me around £2 per day so say £500 per year ish . On top of that there is the ability to use more generated solar maybe another £500 so £1k per year,

that Of course is on todays prices a year ago it would have been half that. Next year who knows?

Guru861

Thanks for thoughts. Difficult decision to be made

Freepost

arty688 said:

So most days I would be charging the battery overnight and discharge before the solar kicks in saving me around £2 per day so say £500 per year ish .

Hi,

If you don't mind me jumping in here, how are you saving £2/day?

Thanks

F.

arty688

The £2 per day is based on Octopus Go tariff .

charge 10kwh off peak at 7.5p and the use it at 30.5p saving 23p per kw so £2.30. There are losses so around £2 seemed ok without getting too complicated.

Sterlingtimes

arty688 said:

The £2 per day is based on Octopus Go tariff .

charge 10kwh off peak at 7.5p and the use it at 30.5p saving 23p per kw so £2.30. There are losses so around £2 seemed ok without getting too complicated.

Octopus gives "love and power" to electric car owners to use Go, but others would fall back to Octopus Economy 7. A rework is required. Day 29.92. Night 21.39. The saving is not impressive on this basis.

Chris_Type_R

Adding a battery might be a useful hedge at this point against the possibility of blackouts in the future. I doubt things will get that bad - but often hear from family in South Africa about the load sharing they have had to endure for years. It's difficult for Europe to pivot away from the dependency on gas supply from Russia. 

Personally I'd be looking at a Victron & Pylontech set up, which can be extended reasonably easily in the future.

Screwdriva

Guru861 said:

Hi, I am trying to get quotes for solar panels. So far only one company has responded.

They have quoted with a battery and one without. The system with the battery is roughly 10k and the one without is roughly 6k.

Is the extra for a battery worth it?

We spend a lot of time at home during the day at the moment due to working from home.

Short answer is, no. Batteries do not make financial sense at this time and probably never will with the advent of vehicle to home charging technology (charge your car during the day and the EV handles your nighttime household requirements). We are only a few years away from being able to go 10 months of the year without using the grid in the UK.

But rooftop solar definitely does, especially if you WFH and plan on owning an EV in the future. ROI on a system with no Chinese brands (Hyundai panels, Solar Edge inverter, 20 year warranty) are now approaching ~7 years before EV savings are factored in. 

Meatballs

You can get a small battery setup from £1600

https://www.itstechnologies.shop/collections/solar-battery-storage-buy-online/products/pylontech-us2000c-2-4kwh-complete-kit-charges-from-solar-octopus-go

Fitting shouldn't be that expensive fairly simple...

This is a modular system so you can increase capacity, but you are far more likely to get a good return on a small battery system that you can fully charge/discharge every day (maybe multiple times with solar), over a large capacity system that covers you during winter but doesn't get used to its fullest in summer.

Solar Facebook groups seem to think battery is instant savings and it's a no brainer but I'm not sure many have run the actual numbers. I think many are addicted to the no grid usage feeling 😅

Whilst battery storage can make energy use more green it's not as straightforward as you would think. Any excess solar you don't use makes neighbours use more green and reduces overall grid CO2. Using a battery has efficiency losses that decrease this benefit. However charging/discharging at low/high CO2 intensity periods could offset the efficiency losses.