11 Sep 2017 | News

Grid connection secured for 3,240MW Cardiff Tidal Lagoon


  • Offer from National Grid Electricity Transmission Plc accepted by Tidal Lagoon (Cardiff) Limited
  • Would be the UK’s largest renewable energy project, capable of powering every home in Wales
  • Located between Cardiff and Newport, it would be the first tidal lagoon power plant at full-scale, made possible by the consented pathfinder project at Swansea Bay
  • Already 3 years into preliminary environmental and engineering studies, a full application for Development Consent for Cardiff Tidal Lagoon is anticipated in 2019
  • As reported to Government by the independent Hendry Review, Cardiff Tidal Lagoon is expected to generate among the cheapest electricity of all new power stations built in the UK


10th September 2017

Tidal Lagoon Power has secured the grid connection for a 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 awaiting final sign off by the UK Government in the coming weeks.

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”.

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.

The UK tidal lagoon industry can be certain in its ability to reduce costs immediately via the physics of simply moving to bigger sites with similar or higher tidal range to Swansea Bay.  It does not rely on an assumption of technology learning or mass manufacturing over time, although these will clearly help drive costs even lower.

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.”

A more stable, more flexible energy system

Tidal lagoons can provide the grid with entirely predictable, year round, zero carbon electricity at scale.  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.

In holding back periods of power generation or pumping for storage, a tidal lagoon offers flexibility and stability to the system, helping to ensure that electricity is generated at the times it is most needed and consumed efficiently at times of over-supply.

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, said: “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.”

An Olympic-sized economic opportunity for the Cardiff Capital Region

With the potential to invest around £8 billion of private capital, spanning between the cities of Cardiff and Newport, the lagoon represents an Olympic-sized economic opportunity to the Cardiff Capital Region, a diverse city region of 1.5 million people consisting of 10 local authorities.  Early independent estimates suggest that over 3,000 construction workers would be required on the build, with the potential to create and sustain over 8,000 Welsh and UK manufacturing jobs in the project’s supply chain.

Leader of Cardiff Council, Cllr Huw Thomas, said: “We welcome this development as an important milestone in progressing a hugely exciting and potentially transformative project for Cardiff and the wider region.  The National Grid deal could play a key role in driving the project forward, making this extraordinary vision a reality. There’s little doubt the opportunities are huge. Thousands of jobs could be created delivering low carbon energy. Cardiff and the city region could become renowned across the world for driving green technologies. We look forward to sitting down with Tidal Lagoon Power to discuss their plans in detail. It’s important Cardiff, its residents and the wider region are all able to capitalise on the opportunities a project of this scale offers.”

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.

According to the Severn Vision Partnership Project, up to 7% of the intertidal area in the estuary could be lost to sea level rise by 2055, resulting in the loss of up to 40% of total saltmarsh habitat.  While affecting some intertidal and subtidal habitats, the Cardiff Tidal Lagoon would offer protection to a large stretch of the habitat under threat while providing additional feeding opportunities to overwintering and resident birds.  The associated Ecosystems Enhancement Programme will look for further opportunities to enhance and create new habitat within the Severn Estuary and further afield, as well as supporting measures to improve the migration, spawning and escapement for key migratory and resident fish species.

Debbie Wilcox, leader of Newport City Council said: “This exciting new project is fantastic news for our city and our partners in the Cardiff Capital Region. It represents a massive boost in confidence in the region and the promise of cleaner, cheaper power and thousands of jobs is very welcome. We wish Tidal Lagoon Power all the best in pulling together such a successful project.”

Lloyds Bank’s Paul Williams said: “As commercial bank to Tidal Lagoon Power (“TLP”), Lloyds Bank is delighted to have been involved with TLP’s pathfinder Swansea Bay project from its infancy, especially as this has now paved the way for TLP’s development of the Cardiff Lagoon project – the UK’s first large scale tidal lagoon project. Supporting low carbon, long dated critical UK Infrastructure is core to Lloyds Banking Group’s Helping Britain Prosper Plan of which renewable energy – and in this case, tidal power – sits firmly within. Renewable energy initiatives such as Tidal Lagoon Power are ‎vital for the progression and development of Infrastructure in the UK.”

Tidal Lagoon Plc

E: Info@tidallagoonpower.com

T: +44 (0)1452 303892

A: Pillar & Lucy House
Merchants Road
The Docks

Tidal Lagoon (Swansea Bay) Plc

E: Swansea@tidallagoonpower.com

T: +44 (0)1792 274006

A: 8th Floor
One Central Square
CF10 1FS

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