A fire damaged one of Europe's largest floating solar plants that is operated by a venture of oil giant BP, Recharge has learned.
Repairs will start next week following an investigation of the fire, which broke out in May following an electrical fault at the 6.4MW floating solar array on the Queen Elizabeth II Reservoir near Heathrow Airport on the edge of London.
The plant is operated by Lightsource BP – 50%-owned by the oil supermajor and a crucial part of its renewable energy plans – to supply power to utility Thames Water, and was Europe's largest floating solar array when it came online in 2016.
The blaze damaged an area where two of the array’s floating platforms met, apparently causing some of the modules to sink into the water.
Confirming the incident Lightsource BP told Recharge: “On 26 May 2020, an electrical fault occurred on the QEII floating solar array. A small fire ensued causing damage to some components.
“On being alerted to the incident, Lightsource BP implemented its HSSE [health, safety, security and environment] protocols to investigate the cause of the incident and to initiate repairs.
“After completing the necessary health and safety processes with subsequent approvals from Thames Water, repairs are due to commence next week.” 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 ensure there were no quality issues as a result of the blaze.
Lightsource BP has not commented on any findings regarding the cause of the fire, which is the second blaze to hit a major floating solar installation within a year. In September 2019 Japan’s largest such array, a 13.7MW plant near Tokyo, burst into flames after being badly damaged in a typhoon.
Like its cousin in the floating wind sector, floating photovoltaics has been hailed for its huge potential in the next wave of the energy transition, with the ability to exploit unused water surfaces to produce renewable power in countries where land may be scarce.
Plants in the hundreds of megawatts, or even gigawatt-scale, are now being proposed around the world.
Technical advisory group DNV GL, which earlier this year set up a cross-industry initiative to develop best practice for the sector, has cited estimates that human-made inland waters alone have the potential to support up to 4TW of new power capacity globally.
Floating PV is also pushing out into the open sea – Recharge reported earlier this year how a pioneering deployment offshore of the Netherlands remained operating after being hit by Storm Ciara.
'Make it watertight'
Robert Heuckelbach, a technical expert on floating and onshore PV at DNV GL, told Recharge that deploying PV on water should in theory be safe – as long as due care is given to the extra risk factors that exist in addition to land-based deployment.
They include ingress of water and moisture to components such as inverters and connectors, and potential damage to cabling caused by the movement of the water – even if this is only gentle, as in the case of a reservoir.
“Connectors are well-known as a risk factor,” said Heuckelbach. “And the cabling in a floating PV plant need special attention, because the floating device moves, and when you use the wrong type of cable it could be you get some damage.”
Although the water offers some advantages in terms of cooling, it can also lead to higher levels of moisture risk for the system, the DNV GL expert added.
“Make it watertight – this is more important than on land-based PV.”
Heuckelbach said despite the extra considerations, there was no pattern of safety risk emerging from the floating PV sector’s short history of deployment, which has seen about 3GW installed globally so far.
The Japan fire he attributed to “bad luck” after a catastrophic weather event, which caused the array’s components to crash together and likely cause a short-circuit.
BP through its joint venture is not the only major energy group active in floating solar, with the likes of Equinor, EDF and Statkraft also exploring opportunities in the sector.
Lightsource BP, which the oil supermajor first bought into in 2018, is pivotal in BP’s plans to become a major global force in renewable energy.
The CEO of the UK-based oil and gas group – which wants a total 50GW renewable energy base by 2050 – this week said Lightsource BP had proved that it was possible to make good returns from renewable energy projects while rapidly ramping up in scale.
Lightsource BP added: “Creating and maintaining a long term, continuously safe and healthy environment is our top priority. We ensure all safety measures are taken to protect our employees, customers and business partners and we are committed to the safe delivery of our projects.
“We put in measures for our contractors to adhere to our high standards in Health and Safety requirements which are governed by our contractor management process.”