Solar PV & Battery
Calculator

Step 1: Choose your region or enter exact coordinates for a more accurate generation estimate. Solar output varies across the UK — southern areas get ~20% more sun than Scotland.

Step 2: Define your solar arrays. Panels on different roof faces count as separate arrays. Each can have its own size, orientation, and tilt. Most homes have 1–2 arrays.

Step 3: Enter your system details. If you used the array builder above, values are already applied. Adjust any numbers as needed.

Step 4: How much electricity does your home use? Pick a preset based on house size, or enter a custom value. Self-consumption % determines how much solar you use vs export.

Step 5: Enter your electricity rates. The import rate is what you pay per kWh. The export rate is what your provider pays you for surplus electricity sent back to the grid.

These settings fine-tune the calculations. The defaults are sensible for typical UK installations — only change them if you have specific information.