about Marine Energy

Tidal energy is the last great untapped global energy resource available to us, with a worldwide potential far in excess of other renewable energy resources.  Caused by the gravitational interaction between the earth with the moon and sun, the movement of tidal waters across the globe is highly predictable and never ending.  The amount of power exctractable from a tidal flow is highest when the flow velocities are highest (usually by an acceleration of the flow due to the seabed or coastline), but a significant amount of energy is also available from medium flow velocity sites too.

Most tidal stream (hydrokinetic) turbines operate by placing a horizontal axis turbine in to the tidal flow, where energy is extracted, much in the same was as a wind turbine operates in wind flows.


With the intelligent implementation of the right technologies, tidal energy has the potential to deliver enormous amounts of clean grid electricity.  The global resource for tidal stream energy is enormous.  Tidal turbines are typically deployed in water of 60 - 120 feet depth in currents exceeding 6 knots (although the Capricorn is designed to capture the lower speed flows).  Because of the difference in density between water and air, tidal stream turbines are smaller than wind turbines of the same power (in other words, produce more energy for a given rotor area).

The USA Dept of Energy has estimated that the total resource available from tidal generation is 250 TWh/year.  To put this in context, the USA consumes a total of 4,402 TWh/year in electricity.  So, the DOE figures would indicate that (for the USA alone), tidal power represents the potential to deliver one sixteenth of the whole country’s annual electricity.  However, this assessment only considers the higher flow sites, as these are where the largest energy yields are available.  The Capricorn technology allows us to exploit lower flow sites, and so we have a significantly larger number of sites available to use, which are typically closer to the centres of population, making connection to the electrical simpler and less expensive.  Therefore, with the Capricorn technology, the exploitable resource in the USA is closer to 527 TWh/year, or one eight of the total annual electricity usage.


Research to date which has been restricted to examining the highest velocity tidal flows worldwide has concluded that there is approximately 120 GW of tidal power available for capture.  However the innovative technologies developed for the Capricorn Marine Turbine mean that it is capable of efficient operation and energy capture at many more sites.

A seabed mounted turbine                                                  A cable-tethered turbine

Renewable Devices Marine Ltd have brought together world class innovation and a proven engineering track record in renewable energy product development, to deliver the world's lowest cost and most environmentally sensitive marine energy, in the form of the Capricorn Marine Turbine - a unique tidal stream turbine design delivering an unrivalled combinaltion of innovation and reliability.

The Capricorn 5 (50 kW turbine) and the Capricorn 125 (1.25 MW turbine) provide the lowest cost, the most reliable and the most environmetally sound marine energy generation anywhere in the world.

Renewable Devices Marine Ltd

AeroMarine House,  15 Roslin Glen,  Roslin Country Park,  Roslin,  EH25 9PX,  Midlothian,  UK

Tel:   +44 (0)131 448 0660          Fax:   +44 (0)131 440 3094          Email:   info@capricornmarine.com.com

© 2014 Renewable Devices Marine Ltd


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