Fresh concerns have emerged over the future of BP’s alternative energy business after a fire broke out at one of the company’s largest solar power installations in Germany.

The incident on June 21 destroyed nearly 200 sq m of one of the world’s largest roof-mounted solar panel arrays on a warehouse complex in Bürstadt, near Mannheim. As outside investigators and BP’s own staff were looking into the cause of the fire, a spokesman for BP Solar confirmed that much of the equipment involved had been supplied by the company four or five years ago.

In the past, concerns have been raised about some junction boxes manufactured by BP Solar, which were said to be prone to overheating. The company recalled and replaced some of these in 2006 and 2007 as a precautionary measure.

Kai Alfermann, head of asset management at Fiege, the German logistics company that owns the site, said that the fire appeared to have started on the array itself and had spread to the timber frame on which it was mounted. He said it was not the first time that the installation had suffered problems and that, depending on the outcome of the investigation, Fiege might take legal action against BP Solar or the German company that installed the equipment.

“The cause of the fire is unknown at this stage and it would be unwise of us to speculate,” BP Solar said.

One well-placed solar industry source claimed that there were concerns about BP’s equipment in the industry, which generated global revenues of $37 billion last year. “Major manufacturers are up in arms because they don’t want to be tainted by this episode,” he said.

News of the fire surfaced days after Carl-Henric Svanberg, BP’s newly appointed chairman, said that clean energy would continue to play a key role in the oil group’s agenda.

Although BP invests more in renewable energy than many of its rivals, there has been uncertainty over its plans for alternative energy. Last month, Tony Hayward, the chief executive, questioned the economics of solar energy, claiming that the technology was unlikely to ever be as competitive as fossil fuels.

“I think solar is probably the most challenged of all of BP’s alternative energy interests,” he told a conference in California.

“It is not going to make the transition to be competitive with more conventional power — the gap is too big. If solar is going to make a breakthrough, there will be a technology disintermediation step.”

Vivienne Cox, head of alternative energy at BP, left the group this month and the company is shutting the head office of its alternative energy business in London. However, BP insists that it remains firmly commited to lower-carbon energy.

BP Alternative Energy operates a range of businesses, including American wind farms, solar power, biofuels, hydrogen energy and carbon-capture and storage projects.

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