Methodology

A useful starting point, with the limits left visible.

HomeWatt Plan is a lightweight decision guide. It turns a small number of household inputs into an indicative system direction; it is not a quote, engineering design or savings guarantee.

What shapes the result

Your country and location, main goal, existing solar, broad electricity-bill range, home type and likely timeline. These inputs help HomeWatt Plan choose a sensible starting range and surface relevant local support.

What the estimate cannot know

Roof orientation and condition, shading, interval consumption, export limits, switchboard condition, tariffs, battery location, planning rules and installation constraints. A qualified professional must confirm all of these.

How to use the plan

Treat it as a comparison brief. Ask installers to explain why their recommendation differs, compare the same assumptions across quotes and check official programme rules before committing money.