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Solar panel savings calculator
Answer four questions to see a rough system size, cost, yearly saving and payback time for your home.
Your home
How we work it out
We turn your monthly bill into a yearly amount of electricity, using the average Direct Debit rates in the Ofgem price cap for October to December 2026: 26.32p per unit and a 54.83p daily standing charge.
We then suggest a system big enough to cover most of that use, between 2 kW and 6 kW, and estimate how much it would produce in your region and on your roof direction. A south-facing roof produces the most. East or west-facing roofs produce somewhat less, and north-facing roofs much less.
Without a battery, a typical home uses roughly half of what its panels make, and exports the rest. With a battery you use much more of it yourself. We value exported power at 12p per unit. Your real export rate depends on your supplier.
For cost, we use about £1,650 per kW installed, plus about £3,000 for a battery. That is in line with recent MCS installation data, but prices vary, so treat the result as a starting point.
This is a rough estimate, not a quote. Shading, roof size, your daily routine and the equipment you choose all change the numbers. An installer survey gives you the real figures.
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