Solar + battery payback in the UK (2026)
A solar + battery install is more expensive upfront but compresses payback by capturing every kWh you generate at full retail value. The combined calculator below models both halves as one system.
Frequently asked questions
Is it cheaper to add battery later or with solar?
Together is usually £500–£1,000 cheaper than retrofitting because the install team is already on site and the inverter is sized once.
What's the realistic combined payback?
8–12 years for a 4kWp + 10kWh system at typical UK install costs (£12–15k). Faster on Octopus Flux because of the higher export rate.
Does the battery pay back without solar?
Yes — see the dedicated 'Are home batteries worth it?' page. Solar makes the combined payback faster but isn't required.