Tidal Lagoon Power has secured the National Grid connection for a proposed £8 billion,  3,240MW capacity tidal lagoon expected to generate among the cheapest electricity of all new power stations built in the UK.

The project, located between Cardiff and Newport, has been selected as the first to employ at full-scale the blueprint being established by the pathfinder Swansea Bay Tidal Lagoon, a consented, world-first project which is currently still awaiting final sign off by the UK Government.

Tidal Lagoon Power’s chief executive, Mark Shorrock, said:

“Our offer to the UK Government is to contract Swansea Bay Tidal Lagoon for a lower subsidy per megawatt hour than Hinkley Point C. While we await the Government’s response to this offer and to the independent Hendry Review of tidal lagoons, we have continued our development work on the subsequent programme.

“Today we have secured the grid connection for a tidal power station equal in installed capacity to Hinkley Point C. Looking at the pounds per megawatt hour unit cost of new build power stations, nuclear is currently priced in the nineties, the latest offshore wind projects are expected to drop into the seventies and our models show Cardiff Tidal Lagoon beating them all in the sixties.

“What’s more, by leveraging the commanding position taken by UK industry preparing for Swansea Bay Tidal Lagoon, the supply chain contracts awarded for Cardiff Tidal Lagoon will be worth more than £6 billion to UK companies”.

Tidal power "less expensive than offshore wind and significantly less expensive than nuclear"

In January this year, the Hendry Review, an independent report to Government by former Conservative energy minister Charles Hendry, concluded that Cardiff Tidal Lagoon could generate power that is “less expensive than offshore wind and significantly less expensive than nuclear”. It found that contracting Cardiff Tidal Lagoon’s 5,500GWh annual output adds less than 50p on average to annual household electricity bills, versus £2.39 for a 5,500GWh portion of Hinkley Point C’s contracted annual output.

The Review concluded that large scale tidal lagoons could be built in the UK at a cost of £65 per MWh to £85 per MWh, which is cheaper than new nuclear and comparable to where UK offshore wind projects are expected to come in. It agreed that as a first step, the UK should proceed ‘as soon as is reasonably practicable’ with the consented pathfinder tidal lagoon at Swansea Bay.

Investec Bank’s Jeremy Ellis said: 

“In our experience and given their sustainable long-term return characteristics, there is likely to be investor demand for both project and development equity of tidal lagoons once there is clarity regarding government support for the pathfinder then a portfolio of full scale tidal lagoons. This grid offer enhances Cardiff’s reputation as a standout full scale tidal lagoon project.”

Tidal power could help to create more stable, more flexible UK energy system

With an annual power output in excess of 5,500GWh the Cardiff Tidal Lagoon will generate enough electricity each year to power every home in Wales, for the next 120 years.

When operating in pumping mode, Cardiff Tidal Lagoon could act as a flexible load for the grid, with up to 2,171MW of demand permitted under the agreement with National Grid. 

Crucially, this could be timed to facilitate the integration of more intermittent wind and solar power and more inflexible nuclear power into the future energy system. A portfolio of geographically dispersed tidal lagoons could further enhance these system benefits.

Phil Sheppard, National Grid’s Director of UK System Operator, commented:

“Tidal power presents a reliable and predictable source of renewable generation that has the potential for highly flexible operation in the future. We have worked alongside tidal lagoon developers to gain an understanding of the operational characteristics of the proposed lagoons. This infrastructure project will have a significant impact as we move towards an increasingly low carbon electricity network.”

Current plans for Cardiff Tidal Lagoon comprise a 20.5km breakwater wall housing up to 108 tidal lagoon turbines within at least two powerhouse units.  By enclosing approximately 70km2 of the Severn Estuary, the project would pass an average of some 600 million cubic metres of water through its turbines on each tidal cycle, more than 11 times the volume of water available to the pathfinder at Swansea Bay.

Real risk investors will walk away unless decision made very soon by the Government

Last week Guto Bebb MP, Parliamentary Under-Secretary of State for Wales faced a string of questions from MPs in the House of Commons asking when the Government would respond to the Hendry review published 8 months ago, which supported a tidal lagoon in Swansea.

Rachel Reeves MP Chair, Business, Energy and Industrial Strategy Committee commented:

“Will the Minister say now when the Government will publish their response? There is a very real risk that the investors that are needed to fund the project will walk away unless a decision is made very soon by the Government.”

Chair of the Environment, Food and Rural Affairs Committee Neil Parish also asked:

“It is nine months since the Hendry review strongly endorsed the tidal lagoon at Swansea, where the rise and fall in the tide is the second highest in the world. It would unlock power for generations, not only on the Welsh side but on the other side of the Bristol channel. When are Ministers going to make a decision?”

However, Guto Bebb  refused to commit himself to a firm date, confining his reply to saying:

“iIt has to be stated on record that although the Hendry review was supportive of a tidal lagoon in Swansea, no real financial issues were dealt with in that report. It is necessary that we make the right decision not just in terms of the concept of a tidal lagoon in Swansea, but for the energy price that the consumer will pay and for the taxpayer. We will make the right decision in due course. “