Port of Mostyn Ltd plans to develop GBP590 million tidal lagoon

Mostyn SeaPower Ltd, a subsidiary of the Port of Mostyn Ltd., has planned to develop a GBP590 million (US$741.4 million) tidal lagoon capable of providing low carbon electricity to power 82,000 homes in North Wales, UK.

Building the 6.7-kilometer long lagoon, stretching from the breakwater at Mostyn to Point of Ayr in Flintshire, would create 300 jobs during the construction phase and up to 30 high-skilled permanent posts.

Mostyn SeaPower said that Dee Estuary is an ideal location because it has one of the highest tidal movements in the UK, as much as 10.2 meters during high spring tides, as well as having natural deep water for the installation of the turbines. The company estimates that the turbines could be turning and producing energy by mid-2027. 

The lagoon wall will be two meters above sea level and another major benefit is that it will provide much-needed flood protection for the low-lying land along the coast which includes homes and businesses, the A548 Coast Road and the strategically important North Wales coast railway line which has suffered significant storm damage in recent years.

It will have two sets of turbine houses with three sluice gates to control the volume of water over the tidal cycle, along with lock gates allowing small vessels in and out of the sheltered lagoon.

In total there will be eight 16 megawatt turbines which will generate 298 gigawatt-hours of electricity annually from the lagoon which will enclose an area of 12.2 square kilometers and has a design life of more than 100 years.

Unlike other forms of renewable energy, like wind and solar, which are subject to the intermittent vagaries of the weather, the tides are constant and predictable, offering a completely reliable supply of power.

Preparatory work, including environmental and ecological studies, has been taking place for four years and the lagoon will be designed to maintain navigational access for shipping.

Mostyn SeaPower has been working with engineering consultants BAM Nuttall and environmental experts ABPMer. The company has already negotiated with the National Grid for the electricity to be used by the nearby Connah’s Quay Power Station.

It is planned to submit an application to the UK Government for a Development Consent Order by the end of 2022 and get the green light a year later.