Ecotricity founder Dale Vince has criticised the cost of the proposed Swansea Bay tidal lagoon and says developing the technology further offshore could be done at almost a quarter of the price.

Vince said self-contained offshore tidal lagoons, which feature rock wall in a closed shape that do not impede boat navigation or fish migration, would be lower cost and safer for wildlife than Tidal Lagoon Power’s proposed 320MW project in Wales.

Ecotricity is in the “advanced stages of assessment” of a competing tidal lagoon technology being developed by Tidal Electric in Scotland, he added.

The Gloucestershire outfit believes lagoons can deliver energy at a cost of around £90 per megawatt-hour for 25 years instead of the £90/MWh for 90 years as is currently proposed for Swansea Bay.

Vince said the government should not give the Swansea project a support deal.

“The government needs to resist giving Swansea Bay a ‘sweetheart deal’ which is hideously expensive and will be forced onto hard-pressed energy bill-payers for the next 100 years.

“Done properly, tidal lagoons can provide power at almost a quarter of the cost of this proposal – and lower than the cost of nuclear,” he added.

A spokesman for Tidal Lagoon Power responded: "Swansea Bay Tidal Lagoon is the pathfinder for a new global industry that can pull down the price of electricity for consumers while allowing them to interact with and learn from the source of that electricity like never before.

"Investors want to fund tidal lagoons, British industry wants to supply them, coastal communities want to host them and with permission to proceed from UK Government we can be on site in Swansea Bay next year.”

Image: Dale Vince (Ecotricity)