Will Renewables Save You Money?

Enter your postcode first, then choose property type, bedroom count, and current heating system. The postcode is used to detect region and load a better default tariff source.

If you have recent bills nearby, use them to sense-check whether the default rates look close to your home.

Select a solar size, then choose whether to add a battery or heat pump. The planner compares the upfront cost with the yearly savings so you can see which setup pays back faster.

A battery usually improves self-use of solar power. A heat pump changes your heating cost and can benefit from the BUS grant. Try different combinations to see where the value comes from.

The tool loads postcode-based tariff defaults (live when available). You can overwrite electricity, gas, and export rates with your own bill values. This matters because small rate differences can meaningfully change annual savings.

If you are comparing supplier offers, rerun with each tariff to see whether the upgrade becomes more attractive.

After you calculate, the result panel shows upfront cost, yearly impact, payback time, 25-year outcome, and a confidence level. You also get a bill comparison to show what may remain after upgrades.

The monthly table explains seasonality: solar tends to be strongest in summer, while heating-related effects are larger in colder months.

The 25-year result is best used for comparing options, not as a guaranteed outcome. It still depends on tariff assumptions, benchmark system costs, and replacement assumptions.

To compare against other uses of the same money, try the Investment Growth Planner. If borrowing is part of your plan, also check the Mortgage Reality Check.

Try at least three versions: base case, a smaller first step, and a cautious case. The tool now includes conservative/expected/optimistic ranges to make this easier.

Once you have a preferred route, use the UK Budget Income Planner to check affordability alongside your wider household budget.

Tariff values are labelled as live or benchmark fallback. System costs, solar yield, self-consumption behaviour, and seasonal heat-pump performance are planning assumptions. The tool also shows a confidence level and expected range to help you judge uncertainty.

The biggest drivers are your electricity rate, your current heating cost, the quoted install price, and whether your home can use a good share of its solar output directly. If your result is close to the line between “good” and “slow” payback, getting proper installer quotes becomes especially important.

Use this tool to shortlist options, not as a final quote. Compare benchmark costs with 2 to 3 installer quotes. If quoted costs are higher, rerun using your own tariffs and compare the expected range before deciding.