A bank of solar panels on the roof of the Scottish parliament building at Holyrood has been written off.

Installed as part of the original design for the parliament the panels were expected to generate enough power annually to heat 40,000 litres of water in Queensberry House. Instead they have caused a host of problems and have now been abandoned.

In 2008 they were discovered to be the source of the deadly legionella bug in Queensberry House. A further outbreak of legionella was found in 2009 and last week officials admitted they had been forced to abandon the panels.

"Recommissioning would have cost around £15,000. Instead we have gone down different routes, with a lot of success," a spokesman said.