Four fire engines and around 25 firefighters tackled a house fire on Ferrymead Avenue in Greenford.
Part of the roof of a semi-detached house was damaged by fire. There were no reports of any injuries. Firefighters rescued a pet snake from a first-floor bedroom.
PVStop, which is a black liquid polymer coating designed to cover solar panels like a liquid tarpaulin, was used to isolate power to ten solar panels.
It works by blocking the sunlight that powers solar panels, so the process of converting light into electricity is stopped. The panels are then de-energised, and the risk of electrocution is greatly reduced so crews can get closer and prevent fire spreading from a roof to the rest of the building.
The Brigade was called at 1625 and the fire was under control by 1857. Fire crews from Southall, Northolt, Ealing and Wembley fire stations attended the scene.
The cause of the fire is believed to have been accidental and involved a solar panel.