Energy from Cornwall

A system that uses the tidal stream in conjunction with the natural rise and fall of the tide to create electricity has been developed by a company based in Cornwall.

A system that uses the tidal stream in conjunction with the natural rise and fall of the tide to create electricity has been developed by a research and development company based in Cornwall.

And the company is hoping that a grant from the UK Department of Trade & Industry (DTI), together with possible support from other commercial organisations, will help turn its concept into reality.

The so-called offshore Ocean Hydro Electricity Generator (OHEG) power plant allows electricity to be generated from the sea, around the clock.

Based on the use of tidal and chamber turbines, combined with energy accumulators, energy is created through the natural tidal stream and the rise and fall of the tide – a more reliable energy source than wind or solar technologies.

The idea is the brainchild of engineers at Hi-Spec Research and Developments of Fowey, and a small team is currently producing a comprehensive report on the mechanical, design and economic viability of the project.

Hi-Spec Managing Director, Pat Cooke, said: “We have brought together a number of existing technologies to create the patented OHEG system. When combined with our own energy accumulator invention, this provides a unique method for generating electricity from the sea, 24 hours a day, seven days a week.”

To date the company has been solely funding this project, but a grant application has now been submitted to the DTI, under their Technology Programme, to help finance a full-scale feasibility study for a plant capable of producing at least 20% of Cornwall‘s energy requirements.

The offshore OHEG structure would consist of three rows of chambers and two outer walls, creating four channels, with the tidal stream then diverted through these channels.

Within the chambers would be groups of energy accumulators which create power from the rise and fall of the tide. Between the rows of chambers and the outer walls are banks of tidal turbines, with four banks per channel. The OHEG plant holds back over 6 million tonnes of water every six and a half hours and in doing so creates power through the chamber turbines.

The plant also makes a suitable foundation for offshore wind turbines, although they are not essential for its operation, and the OHEG system is six times more powerful than the wind farm it supports.

Said Mr Cooke: “An ideal location would be the Bristol Channel, due to its high tide heights, strong tidal flow rates and a flat sea bed of the right depth. Our initial calculations show that the OHEG system alone would be capable of producing 200MW of electricity, with an additional 30MW achieved by the wind farm. Currently Cornwall uses about 650-700MW”.

“Whilst some concerns have previously been expressed regarding the possible erection of a barrage or dam in the Bristol Channel, which might perhaps then have an adverse effect on the immediate environment, it should be stressed that the OHEG is neither a barrage or a dam”.