Guide: solar + battery
Do not let a battery hide whether the solar system is good value
Solar and storage work well together, but they earn money in different ways. A bundle should still be priced as two purchases so you can see what each one is doing.
Last reviewed: September 2026
Ask for three prices
- Solar-only installed price.
- Battery-only installed price, including inverter changes if needed.
- Combined solar-and-battery installed price.
If the installer only gives you a bundle, ask them to split it. Without that split you cannot tell whether the battery improves the economics or simply makes the annual saving look larger while adding more capital than it returns.
What the battery is buying you
Solar saves the full import price on electricity you use as it is generated. A battery stores surplus that would otherwise be exported and returns it later. Its value is therefore driven by the difference between your import and export rates, the amount of surplus available and the battery's losses.
Use the solar calculator first without a battery, then add the battery cost and compare what happens to annual benefit and payback.
Turn an estimate into a quote you can compare
Calculator results are useful for deciding whether a system deserves a closer look, but an installer quote is where roof access, scaffolding, electrical work, inverter choice and the exact battery specification become real. Keep the calculator assumptions beside the quote so you can spot where the sales forecast differs from your own numbers.
Before choosing an installer, use the solar quote comparison checklist and ask every company for the same itemised information. You can also read our guide to comparing solar installers before signing anything.
Battery specifications that affect the price
- Usable capacity rather than nominal capacity.
- Continuous power output.
- Round-trip efficiency.
- Hybrid inverter or separate inverter requirements.
- Backup-power hardware, if you actually want it.
- Warranty years, cycles or total throughput.
- Any electrical or consumer-unit work.