Creating six coastal lagoons to harness power from the tides could contribute £27 billion to the UK economy over a 12-year build programme, a new report has suggested.

A study by the Centre for Economics and Business Research also said the proposed lagoons, if built, would supply 8% of the UK’s electricity and contribute £3.1bn a year over their 120-year lifetime.

The programme would create thousands of jobs, cut carbon emissions and, by putting the UK at the fore of developing the technology, could help secure up to £70bn in exports.

Lagoons could also have other benefits, such as flood protection to at-risk coastal communities, the study suggested.

The report was commissioned by renewables company Tidal Lagoon Power, and examined its proposals to build a series of tidal lagoons around the western coast of the UK, the first of which is planned for Swansea Bay.

If planning permission is received, work on the £1bn Swansea Bay tidal lagoon power plant, which will generate renewable energy by capturing and releasing tidal water through turbines, will begin next spring.

The company aims to scale up the lagoon design to build five larger tidal power plants in the Severn Estuary, north Wales and the north-west coast of England in a process which would see all six completed by 2027.

The report found constructing the six lagoons over a 12-year period could create or sustain up to 35,800 jobs a year on average during that time, and up to 70,900 jobs at its peak.

It predicts the operation of the lagoons, and the electricity they produce, will contribute £3.1bn a year and support up to 6,400 jobs.

The Swansea Bay project will source 71% of its products and services from the UK, and aims to source almost half from Wales.

Harnessing the tides for power would provide predictable renewable electricity, which could end up cheaper than other low-carbon sources of energy such as nuclear and offshore wind.

Putting lagoons built to withstand storms and sea-level rises in areas at risk of flooding such as Colwyn Bay, where one of the six plants is planned would also help protect vulnerable communities from floods, the report said.