Battery · 6 min read
Are solar batteries worth it in the UK?
Batteries get added to most modern solar quotes by default, but they don't make sense for every home. The honest answer comes down to when you actually use electricity and how the export tariffs in your area stack up.
Key things to consider
Evening electricity use
Batteries shine if you're out during the day and back home in the evening — solar generated at midday gets stored and used when you need it.
Self-consumption
Without a battery, most homes use 30–40% of their solar generation directly. With a battery, that rises to 70–85%, depending on size and usage.
Rising tariffs
If grid prices rise further, the battery's savings rise with them — and the value of self-consumed solar increases.
Backup protection
Some systems offer backup during power cuts. Useful in rural areas; less critical in town.
Pros
- Significantly higher self-consumption of solar
- Pairs well with off-peak EV tariffs
- Optional backup for power cuts
- Adds practical resilience to your energy setup
Cons
- Adds £3,500–£7,000 to the install cost
- Slower payback than solar alone in many cases
- Capacity slowly degrades over 10–15 years
- Oversizing without need is the most common mistake
What it actually costs
Realistic payback
Paired with solar and a smart tariff, a correctly sized battery typically pays back in 8–11 years. Oversized batteries stretch that past 12.
FAQs
How big should my battery be?
Match it to evening usage, not solar generation. For most UK homes, 5–10 kWh of usable capacity is the sweet spot.
Can a battery power my whole house in a power cut?
Only if it's specifically wired for whole-home backup. Standard installs usually power essentials only, if at all.
Do batteries need much maintenance?
Very little — they're sealed units. Most installers offer a free annual health check.
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