A British engineering company developing innovative tidal turbine technology has established a projected electricity generation cost of £114/MWh, potentially opening the way for commercial tidal range projects around the UK coastline.
Cardiff-based SETB has completed an extensive programme of turbine design, computational fluid dynamics (CFD) modelling, physical testing and independent engineering validation for its very low head turbine (VLHT), designed to overcome some of the technical and economic barriers that have held back tidal range energy.
The technology is designed to operate efficiently at water-level differences of just 0.5 – 4 m, extending the generating window compared with conventional tidal turbines.
Its innovative contrarotating, bi-directional design allows electricity generation on both incoming and outgoing tides, while operation at lower retained water levels could reduce the size and cost of civil engineering structures required for tidal range schemes.
These advances underpin SETB's projected levelized cost of electricity (LCOE) of £114/MWh, demonstrating the potential for its technology to compete economically with other low-carbon generation technologies.
The company believes its technology could also help unlock significant generating capacity from tidal lagoons and other tidal range developments, providing a predictable source of renewable electricity to complement wind and solar generation.
Steve Prendergast, Chairman of SETB, said: “Tidal range has enormous potential, but the challenge has always been making it commercially viable.
“Our engineering programme has focused on extracting more energy from each tidal cycle while reducing the infrastructure costs that have traditionally made these projects difficult to progress.
“Establishing a projected cost of £114/MWh is an important milestone. We now want to demonstrate the technology in an operational environment and establish a route to commercial deployment.”
SETB's turbine operates at a low rotational speed of approximately 25 rpm, with two sets of contra-rotating blades designed to maximise energy capture from low-head tidal flows.
The company believes its turbine could also deliver significant environmental benefits. By generating electricity over a longer tidal cycle, it could reduce impacts on sensitive intertidal habitats, while its low rotational speed could reduce the risk of injury to fish passing through the turbine. Both are key environmental concerns that have historically challenged tidal range developments.
The technology has already attracted commercial interest, with the developers of the proposed West Somerset Lagoon providing a letter of intent for 250 SETB turbines, each rated at 10 MW, representing a combined generating capacity of 2.5 GW.
SETB is now seeking approximately £5m to establish a 2.5-metre turbine demonstrator at Barry Dock in South Wales, working with Associated British Ports (ABP). The demonstrator has a projected generating capacity of approximately 640 kW and would provide operational validation ahead of wider commercial deployment.
The development programme has involved engineering firms Jacobs and Amen-tum, alongside Cardiff University, Lancaster University, and Liverpool John Moores University, and has been supported by a £1m Innovate UK Smart Grant.
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