Most UK solar panel fires caused by DC isolators: Report

Jack Unwin 19 March 2019 (Last Updated March 19th, 2019 16:32)

The UK government released a report on Tuesday on why fires had occurred at 80 solar panel locations throughout the country.

Most UK solar panel fires caused by DC isolators: Report
A UK Government report finds that DC isolators are the main cause for solar panel fires. Credit: Zbynek Burival / Unsplash.

The UK government released a report on Tuesday on why fires had occurred at 80 solar panel locations throughout the country, in response to media coverage linking photovoltaic power systems (PV) with fires.

The report, “Fire and Solar PV Systems, Investigations and Evidence”, was prepared in May 2018 and released by the Department for Business, Energy & Industrial Strategy (DBEIS).

Of the 80 solar panel fire incidents investigated the study found that 58 were directly caused by the PV system, with 22 of those leading to serious fires and 27 localised fires. A further 16 involved PVs but were not directly caused by them, of which 15 led to serious fires. In total, 38 incidents were serious fires, 33 were localised fires and nine thermal events. Just six of the incidents took place at solar farms, with the other 74 taking place in buildings.

It was found that direct current (DC) isolators presented the greatest fire risk as the probable cause of 26 of the 80 fires, which the report said were due to poorly designed and installed isolators. DC connectors were the second major fire risk, the cause of five probable and seven possible fires.

The report identifies the most likely cause of fire as electrical arcing, where electricity flows through an air gap through ionised gas molecules and become hot enough to cause combustion. In total, these incidents have led to 13 injuries, including three fatalities.

In the introduction to the report, the authors note that there is little information on PV fires. The data published by the government cannot specify whether fires were caused by PV systems, and some incidents may have not been reported due to being contained by the owners of the systems.

The authors wrote that they hope the report will “feed the data and conclusions into industry standards and the National Occupational Guidance system, which is used to disseminate information to the fire and rescue services.”