Illustrative estimate only · No login · No personal information collected · All calculations run in this browser
1. Your proposed solar system
Ask installers for the installed kWp rating. 4 kWp is an example, not a recommendation.Starting assumption only. Local sunshine, roof direction, tilt and shading affect actual production. Request a site-specific forecast.Use varies with daytime activity, electric heating, EV charging and storage. Avoid assuming all generation offsets purchased electricity.Enter your own tariff or supplier's export offer. Neither rate is a guaranteed or current market-wide tariff.
2. Installation costs
Do not deduct speculative grants. Enter financial support only once it is confirmed and applicable to this installation.
3. Your estimated outcome
Check the figures. The amount of support cannot exceed the installation price.
Installed cost—
Net cost after confirmed support—
Electricity generated each year—
Annual export income—
Estimated yearly bill reduction plus export income—
How we calculated it
Your estimate assumes stable annual generation, self-use, unit prices and export terms. It excludes maintenance, inverter or battery replacement, panel degradation, financing, scaffolding variations, VAT treatment and any changes to tariffs. A site-specific installer survey is required.
Next practical steps
- Check your electricity bill for your import unit price.
- Ask for a roof-specific generation forecast and full installation quotation.
- Verify any export tariff and meter requirements with your supplier.
- Compare at least two quotes and check installer accreditation.
Energy Saving Trust solar guidance · Ofgem Smart Export Guarantee