Calculator category

Solar & Battery Calculators UK

Independent tools for checking solar generation, installer quotes, battery payback, solar self-consumption and battery sizing.

Use the quote checker when you have an installer proposal; use the battery tools when the question is specifically about storage economics or sizing.

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Solar & Battery Quote Checker

Model postcode-specific PVGIS generation and compare installer generation, savings and payback claims.

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Plug-in Solar Payback

Model a small plug-in solar kit with postcode-specific generation, clipping and in-home self-use.

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Home Battery Payback

Estimate battery payback from installed cost, usable capacity, cycling, losses and tariff value.

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Solar + Battery vs Solar Only

Measure the incremental financial value of adding storage.

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Solar Self-Consumption Value

Value additional solar self-use after accounting for export income forgone.

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Battery Size Optimiser

Compare smaller and larger batteries using the marginal value of extra capacity.

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How to get a more useful result

Use your own tariff or quote figures, then run the calculator again with a more conservative assumption for the input you are least sure about. A decision that still looks sensible under both cases is more robust than one that only works under optimistic inputs.

Separate generation, timing and storage

Solar and battery economics are easier to understand when three questions are kept separate: how much electricity the panels generate, how much of that generation the home can use directly, and how much additional energy a battery can shift into later demand. Combining all three into one assumption can make a quote look more certain than it is.

Start with postcode and roof inputs for generation, then consider the household's daytime demand and export rate. Only after that should battery capacity and cycling be added. This sequence makes it clear whether value comes from the solar array itself or from extra storage.

Compare quotes on consistent assumptions

When two installers use different generation forecasts or electricity-price assumptions, payback figures are not directly comparable. Re-enter both quotes using the same tariff, export rate and household demand so that system size, price and expected performance are being compared on the same basis.