A £7 billion tidal lagoon could help protect the Conwy and Denbighshire coastline from future flooding and climate change, a developer has said.
North Wales Tidal Energy is currently lobbying both the Welsh and UK governments for funding after receiving the support of both Conwy and Denbighshire councils.
The company, set up in 2014, is hoping to raise the £50m needed for detailed environmental impact assessments before it gets permission.
Once that is in place, the company will target both government funds and private investment, promising enough electricity to power every home in Wales. The project could also offer a return of £500m a year.
But Henry Dixon, the chairman of North Wales Tidal Energy and a founding member, also says the lagoon’s 4m-high wall two miles out to sea could protect the coast from storms and rising sea levels due to climate change.
Both Conwy and Denbighshire county councils are investing millions of pounds of Welsh Government funds to stop flooding, coastal erosion, and sand loss on beaches vital to the tourist industry.
But Mr Dixon believed the £7 billion project could be the answer.
“Right from the start, the objective was not just the tidal energy but also to use the lagoon wall to protect the coastline and the infrastructure from flooding, which is going to be more and more of a challenge over the next few years because of climate change,” said Mr Dixon.
“But this wall would stop the storm surges coming in. The big issue is when you get a storm surge coming in and we have had significant rain, so it’s when the two things combine. If you imagine a big wall built about two miles offshore, that wall will stop the big waves that have been travelling for miles.”
The lagoon will feature a classic rock armour structure and thirty or forty-metre-long caissons. These will be constructed in shipyards, towed into position, and dropped ten metres deep, saving lorries bringing the materials in.
The lagoon itself would work by delaying the tide and holding the higher water level at bay. When the turbines and sluices are finally opened, the sea flows into the lagoon over two or three hours. This flow drives the turbines, which then creates electricity, and the process is reversed when the tide is moving in the opposite direction.
“If we can see there is an issue (a storm) coming, then you can close all the sluices, close the locks, close the turbines, and stop the water coming, so you can hold the lagoon level as it is low tide, and then all the water in the River Clwyd can then flow out, and it is not going to be a problem, and you are not going to have this high water level with high waves,” said Mr Dixon.
“You can really help mitigate the challenges of, particularly, storm surges but generally the rising sea levels.
“But the lagoon has all these other benefits that no other plant can offer, in that it will protect the A55; it will protect the railway; it will protect all the assets. We had a study done. They calculated our lagoon would protect £3 billion of our assets along the North Wales coast.”
A spokeswoman for Conwy County Council commented: “The council is very supportive of a tidal lagoon for all the environmental and economic benefits it would bring. We would welcome financial support from Welsh Government to enable full feasibility studies to be carried out which will enable the plans for the scheme to be taken to the next stage.
“The benefits of a tidal lagoon are recognised. However, with no assurances that it will come forward, or by what point, the future defence works are needed in order to protect the coastline and coastal infrastructure from flood events, as well as providing improvements to public spaces and National Cycle Route 5.”
A spokesman for Denbighshire County Council commented: “At a meeting of Full Council on February 22, a notice of motion was approved which stated the council would support in principle the development of a large scale tidal energy project by the private sector off the Denbighshire coastline.
“After the election in May a group of elected members will be set up to monitor and evaluate progress on the scheme and to lobby both governments to support the project.
“We are continuing to work to protect residents and businesses in our coastal communities with our planed and completed flood defence projects. These schemes will protect the area from current storms and future rises in sea levels. We would work with those behind any potential future scheme undertaken by the private sector to ensure it complements these works.”
Andrea Winterton, Marine Services Manager for Natural Resources Wales, said:
“We’re aware of the proposals for the tidal lagoon between Prestatyn and Llandudno in North Wales.
“We understand the scheme is currently at the early design stage and welcome the opportunity to continue to engage with the applicant so we can make sure all the necessary environmental and licensing requirements are considered.”