Helios launched a calculator that lets UK address estimate electricity from a plug‑in solar panel. The tool appeared as British regulators approved kits, which require no electrician or planning permission, as the UK plug‑in solar market opens. Users input postcode, floor and balcony orientation, then see annual generation and monetary value against their tariff. It visualizes shading on a map, highlighting buildings that block sunlight.

Helios cross‑references the postcode with Ordnance Survey data, ray‑traces surrounding buildings using Environment Agency LIDAR, and feeds the resulting shading map to PVGIS for an annual yield estimate. Areas outside LIDAR coverage—most of Scotland and Wales—revert to a synthetic horizon, reducing accuracy. Recent trees or developments may also be missing, and address pinpointing relies on OpenStreetMap geocoding.

The calculator assumes the UK cap of 800 W inverter output, typically two 0.4 kWp panels, and lets users enter kit cost, self‑consumption rate and tariff details. Results show annual kWh, payback period and twenty‑year net savings, noting that most kits cannot claim the Smart Export Guarantee. Helios offers a transparent way to gauge whether a plug‑in system makes financial sense, including labor costs.