The starting point

A useful solar plan connects the roof’s potential with the electricity you actually use. Panel count is a starting point; timing, storage and installation constraints shape the outcome.

Make the roof assessment useful

Bring together the roof orientation, pitch, usable area and obstructions. A desktop estimate can help compare possibilities, but an installer still needs to check the roof and electrical installation.

Ask for the proposed panel layout, the reason for that layout and the assumptions behind the generation estimate. Keep roof repairs and access requirements in the same conversation.

Compare the same household

Use the same annual consumption and tariff when comparing panel layouts. Otherwise a larger saving may come from a different assumption rather than a better system.

Our suggested comparison is three layouts, each with storage, followed by a review of the winter and evening periods. Do not treat annual generation as a promise of round-the-clock independence.

What to prepare

Your electricity use in kWh is more useful than a direct-debit amount. Note any planned EV or heating change separately so it is not counted twice.

  • Annual electricity consumption and current tariff.
  • Roof photographs and any planned roofing work.
  • When people are normally at home.