Electrical fault sparks fire at Queen Elizabeth II reservoir floating solar array
EIR-0948Other entries that name Elizabeth
Provisional entry. Published from first reports. This entry is rechecked automatically and updated when more sources appear. Next update: 19 September 2026.
On 26 May 2020 an electrical fault caused a small fire at the Queen Elizabeth II reservoir floating solar array near Heathrow Airport, on the edge of London. The 6.4MW plant, operated by Lightsource BP to supply power to utility Thames Water, was Europe's largest floating solar array when it came online in 2016. The fire damaged an area where two of the array's floating platforms met, apparently causing some solar modules to sink into the water. Lightsource BP said it implemented its health, safety, security and environment protocols to investigate the cause and initiate repairs. Thames Water said the water stored at the reservoir was at the pre-treatment stage rather than for drinking, and tests were carried out to check for any quality issues. Repairs were reported as due to start in the week following publication in September 2020, roughly four months after the fire. The source reports no injuries.
Lightsource BP attributed the incident to an electrical fault, and did not comment publicly on any findings as to its cause. The damage was concentrated in the area where two floating platforms met, although the source does not state that the fault itself originated there. A technical expert quoted in the report noted that floating solar installations face additional risks compared with land-based systems, including ingress of water and moisture into components such as inverters and connectors, and cable damage caused by the movement of the floating structures.
- Floating solar developers should ensure connectors and cabling are specifically rated and installed to withstand the movement of floating platforms on water.
- Watertight design and moisture protection for electrical components are especially important in floating PV systems compared with land-based installations.
- Operators should maintain clear HSSE protocols covering prompt incident investigation, water quality testing where the host water body has another use, and coordinated repair planning with the site's customer or landowner.
Published 2026-09-17. Written from public reporting. Descriptive, not investigative. See the data accuracy disclaimer.