How we check figures

Solar is full of numbers that go out of date: export rates, VAT dates, typical costs, planning limits. Here is our approach.

Primary sources only

We take figures from the organisation responsible for them:

• Schemes and law: GOV.UK, legislation.gov.uk and Ofgem.
• Typical costs and savings: the Energy Saving Trust.
• Installers: the MCS register and the consumer codes’ own directories.
• Panels: the manufacturer’s own datasheet.

Dated, and in one place

Every figure is stored once, with its source and the date we read it (most recently 15 October 2026), and every page that uses it reads it from there. When a figure changes, it changes everywhere at once.

Self-descriptions are labelled

When we report what a company says about itself, such as where it manufactures, we say that it is the company’s own description. When we could not confirm something, we say so.

What we will not publish

• Reviews, testimonials, case studies or installation counts. We are not an installer and have none.
• Claims that anything is “free”, “official” or government-approved unless the source says so.
• Supplier export-rate tables we cannot keep current.
• A phone number. We work through the enquiry form only.

Datasheets: the exact model

Manufacturers sell several variants under one product name, and efficiency, warranty and degradation figures differ between them. When we quote a datasheet we name the model range, link the document, and tell you to check the exact model number on your own quote. Where copies of a datasheet disagree, we say so rather than pick one.

When figures change

Export rates move on short notice, the VAT relief has a fixed end date, and planning law is amended from time to time. We re-read our sources and update the read date when we do. If GOV.UK, Ofgem or a manufacturer says something different from this site, they are right.

Found an error? Tell us.