Honest, or nothing.

solar.day answers one question: does solar actually make sense for your home? Not for the average home. Not for the home an installer wants you to have. Yours. We rank four routes – rooftop panels, rooftop with a battery, a battery on its own, and the new plug-in kits (launched at £849, heading for £500) – and if none of them stacks up, we say so. 'Not yet' is a real answer here, not a failure.

We're not anti-solar. The opposite – done right, it's brilliant, which is why it deserves honest arithmetic instead of a brochure.

Every number is sourced and dated. Self-consumption comes from the MCS tables an installer is required to use. Costs come from the government's own installation data. The plug-in figures come from the DESNZ impact assessment behind the law change. When we estimate, we say we're estimating.

We're independent. No installer commissions, no supplier deals, no lead selling. Nobody pays us, and nobody edits our numbers.

solar.day is built by Mat Moakes as part of the Green But Not Heard project – a book and a set of tools arguing that the energy transition has a marketing problem, not a technology problem. The book is out in September; the tools are free either way.