Scottish renewable energy firm Aquamarine Power racked up a further multi-million-pound loss last year amid increasing uncertainty in the sector.
Full-year accounts which were published at Companies House yesterday show the Edinburgh-based developer plunged £16.5m into the red in the year to March 31.
The return, a significant improvement on the £35m loss of the previous year, included a £12.7m impairment on the value of its flagship Oyster technology.
The company said the board had approved the move as a result of continuing uncertainty over how long it would take to prove out Oyster, and a lack of clarity over the future operation of the UK energy market which has stalled investment in the sector.
CEO Martin McAdam said: “We have taken a view that there is uncertainty in the technology development and in market conditions and we have decided to write down the value of the capitalised asset.
“When the uncertainties reduce, we will be able to capitalise costs in the future.
“We continue to make good progress on the technology development and we have raised £6.8m in funds since the year end.”
He added: “Our product improvement plan for 2014 is well under way, and we hope to have improvements installed on the machine and we will be back studying the machine performance at EMEC in Orkney before the end of the year.”