Guides and comparisons

Solar and battery payback in the UK depends more on your tariff than on sunshine. The real methodology — sizing, self-consumption, export vs storage.

South isn't the only viable orientation for solar. Here's how much output you actually lose on SE, SW, east, west and flat roofs — with real percentages.

Solar panels convert sunlight to electricity via the photovoltaic effect. Here's how the process works, what affects real output, and where the energy goes.

Usable capacity, not nameplate size, decides real value. Comparing GivEnergy, SolaX and Pylontech on what you actually get per pound, not headline kWh.

Air-to-water and air-to-air heat pumps aren't the same decision. Running costs, grant eligibility, and the scheduling lever that decides if either beats gas.

The £2,500 air-to-air grant is real, but a common setup — keeping gas for hot water — likely disqualifies you. Here's the eligibility catch most guides miss.

MCS decides whether a heat pump qualifies for the Boiler Upgrade Scheme, and whether solar earns export payments. What it covers, and how to check it.

One rule decides whether to export solar, charge a battery, heat water, or charge your EV with it. Here's the method, applied step by step to your own rates.

What the Smart Export Guarantee is, who has to pay you, why rates range from about 4p to 12p and more, and how to pick an export tariff.

Economy 7 needs about a third of your electricity at night to beat a single rate. How solar, batteries, storage heaters and heat pumps change that.

Octopus Cosy's midday cheap window changes the maths for solar, battery and heat pump sizing. Here's how it compares to a simple overnight-only tariff.

Solar diverters don't automatically save money — it depends on your export rate. The comparison done properly, with the old Feed-in Tariff advice corrected.

Everything the £9.99 Deep Dive adds to your free results: month-by-month figures, the full off-peak range, your roof image, 25-year cash flow and a PDF.