Calculator

What should I install first?

Start with a quick estimate — about a minute. Add more information only if you want a more personalised result. You do not need your tariff, your bills or any smart-meter data to get a first answer.

Illustrative prototype — do not use this to make a purchasing decision

This prototype demonstrates the WattFirst planning experience using illustrative, unverified assumptions. Do not use it to make a purchasing or financial decision.

Step 1 of 4Your home

Your home

Two or three details about the property.

The first part only, for example L40 or NG7. This will eventually support regional solar and tariff data. We do not ask for your full postcode.

Property type
Household size

How many people normally live there.