The 30MW tidal fence is to be built in the Severn Estuary
Kepler Energy has begun fundraising to take a proposed £143m energy-generating tidal “fence” through development and the planning process.
The 30MW fence, planned to be built in the Severn Estuary, is the latest project hoping to generate electricity from the UK’s tide, following planning permission for the planned £1bn tidal lagoon in Swansea Bay, and the announcement of plans from Natural Energy Wyre to build a 600-metre barrage across the river Wyre near Fleetwood in Lancashire.
Kepler Energy, a commercial spin off from the University of Oxford’s department of engineering science, aims to initially place 14 horizontal turbines in the Bristol Channel in a 1km long array. Each turbine is 60m in length and around 10m in diameter.
Unlike tidal devices that use a conventional axial turbine, which superficially resembles a wind turbine that has been converted for use underwater, the tidal fence is made up of horizontal turbines that consists of a stressed truss configuration of carbon composite hydrofoil blades.
Peter Dixon, chairman of Kepler Energy, told Construction Manager that now was a good time to announce their plans: “It is a good time to let people know what we are doing – we have confidence from the research work we have done and tidal power is at the top of people’s agenda.
“The Swansea lagoon has given confidence to potential investors that there is a real industry to be had, and that we are a viable investment,” he continued.
Testing and detailed modelling has been carried out
After extensive research funded by Oxford University and the Technology Strategy Board (now Innovate UK ), along with £30,000 won through the Shell Springboard programme, the company is now confident that it can offer a realistic prospect for investors.
“We have carried out a lot of testing and detailed modelling at the university [of Oxford] and along with the research carried out into costing with our supply chain, we are confident that it is feasible,” says Dixon.
At present the project needs funding so that it can carry out further site-based development and then submit a planning application, with the turbines potentially generating energy by 2021.
“For everyone involved in the tidal industry the planning process is a big hurdle,” says Dixon. “We also need to monitor the effects that the turbines would have on the sea for at least a year.”
Fourteen horizontal turbines will be placed in a 1km long array
In a statement issued by Kepler Energy, Dixon stated that the proposed turbines could be deployed around the UK, where there is suitable tidal flow. It could also work in unison with lagoon projects: the team behind the Swansea lagoon has also identified five other locations around the UK.
Dixon said: “As our tidal technology can operate in lower velocity tidal waters, there is greater scope for its deployment in the UK and overseas. It means that we can achieve greater economies of scale as our projects are deployed.
“We can happily co-exist with tidal lagoons, and the power peaks will occur at different stages of the tide, meaning that the combined output into the grid will be more easily manageable.
“In addition, our levelised costs of production will be in the range £100 to £130 per MWh for utility scale production, so costs will be cheaper than lagoons and in time we will be cheaper than offshore wind generation. Furthermore, investment risk is manageable since turbines are added incrementally to form the fence, with each one generating revenue as it is added.”
