Image copyright Tidal Energy Ltd Image caption The £16m DeltaStream project uses tidal power to provide renewable electricity

A failed £18m tidal energy project in Pembrokeshire stopped generating electricity after just three months because of a fault, its operators have admitted.

Tidal Energy Ltd went into administration in October, but the 400KW, 39ft high turbine in Ramsey Sound, had not worked since March.

Development director Chris Williams defended the research project.

The Welsh Government said a buyer was being sought.

Mr Williams said the DeltaStream device was never intended to generate massive amounts of electricity, but it did work for a period of time after its installation in December 2015.

The scheme received £8m in EU funds but market forces had led to the company's financial struggles causing its collapse, he previously revealed.

Image copyright Tidal Energy Ltd Image caption The project received grants including from the Welsh Government and Europe

Mr Williams, who is helping with the firm's administration, said the device had developed "an intermittent fault with an active sonar" in about March which was part of the system's marine monitoring equipment.

The sonar was used to detect nearby wildlife, analysing the possible impact on marine mammals.

But when the fault developed, the project was no longer able to detect a potential collision and the turbine could not operate within its licence.

A mechanical defect also later developed on the turbine which would have prevented it from generating, Mr Williams explained.

He said this happened before the firm went into administration.

"The project was a research and development project. It was never put in the water to generate massive amounts of electricity," he added.

Image caption DeltaStream before it was installed

"The purpose of the project was to provide the essential learning, new knowledge, knowhow and experience to progress the industry in Wales."

"What we set out to do we did, 100%," he said.

Mr Williams also said a £1.4m grant offer from the UK government to remove the turbine to carry out improvements during the summer, was turned down "because we were looking for new funding".

Tidal Energy Ltd had received £7.99m of EU structural funds to develop, build, deploy and test the tidal device.

The money was provided through the Welsh Government's EU funding agency, the Welsh European Funding Office.

The Welsh Government also invested £49,000.

Media playback is unsupported on your device Media caption Tory AM Nick Ramsay asks if the tidal project had shown value for money

In a written answer to a question from Welsh Conservative leader Andrew RT Davies, Economy Secretary Ken Skates said there are a number of marine technology companies who have an interest in purchasing the company's assets, including the Ramsey Sound test site.

Mr Davies described the situation as "extremely concerning".

"The first minister once hailed the development of the turbine a 'landmark project' for Wales. It is sad and deeply frustrating to think of it now broken on the ocean bed," he said.

A Welsh Government spokeswoman said a buyer was being sought.

She added: "Tidal Energy Ltd's EU funded project did achieve its primary objective and has provided a significant amount of learning to the sector and the local supply chain.

"This has helped make Wales a key player in the developing marine energy industry and we are keen to build on this success. "