The business behind the Swansea Bay Tidal Lagoon has submitted an environmental-impact assessment document to the Welsh Assembly for a tidal lagoon near Cardiff that it claims could generate enough electricity to power every home in Wales throughout its 120-year life.

Tidal Lagoon Power says the proposed project follows its plans to establish the Swansea Bay Tidal Lagoon — a scheme that was developed to establish a scalable blueprint for the sector and is due to receive a planning decision by 10 June. In December, the Swansea Bay project was named in the Treasury’s National Infrastructure Plan.

Mark Shorrock, chief executive of Tidal Lagoon Power, said: “Full-scale tidal-lagoon infrastructure gives the UK an opportunity to generate electricity from our amazing tidal range at a cost comparable to fossil fuel or nuclear generation. We have the best tidal resource in Europe and the second best world-wide. We now have a sustainable way to make the most of this natural advantage.

“We will build on the template established for the Swansea Bay Tidal Lagoon to deliver a Cardiff Tidal Lagoon that will be capable of supplying around 1.5 million UK homes with affordable, reliable, low-carbon electricity.”

Tidal Lagoon Power has also confirmed that early feasibility work is underway relating to four other full-scale UK tidal lagoons — at Newport, West Cumbria, Colwyn Bay and Bridgwater Bay. Together, these six lagoons could meet 8% of the UK’s total electricity requirement, according to Mr Shorrock.

The plans for Cardiff Tidal Lagoon include up to 90 turbines set within a 22km breakwater that will enclose an area of around 70km2 where the average tidal range is 9.21m. “There is still a long way to go and many environmental surveys to undertake, but we will work in partnership with all the nature conservation bodies to understand, minimise and mitigate any environmental impacts.”

The company expects to submit a full planning application for Cardiff Tidal Lagoon in 2017, with a decision then expected in 2018. The lagoon would take up to five years to build.