Marine Renewable Energy Technology

There has been a lot of information available recently on developments in the marine renewable energy field, but it should be borne in mind that most of these wave and tidal technologies are still at an early stage of development. It is not anticipated that the Island will be able to receive any energy from tidal power for a few years (the exact date is difficult to accurately estimate), but it is important that RET and the Guernsey in general are ready to utilise these new technologies, when the time is right.

Trial/small commercial projects are soon to be set up in a number of locations, including in the Raz Blanchard (Alderney Race) a strait that runs between Alderney and Cap de la Hague which experiences strong tidal flows.  In addition there are projects being developed for an area of sea off Paimpol on the Brittany coast and in the South-West of England at Have Hub. In the Pentland Firth in Scotland there is the European Marine Energy Centre (EMEC) where a number of wave and tidal devices have already been deployed. There have also been sea trials of devices in America and Canada, as well as planned deployments in Asia and Australasia. Late in 2016 the first tidal array in Scotland was installed as part of the MeyGen Project by Atlantis Renewable Corporation - more information on the project can be found at

Technologies currently being used are not yet in commercial production. This, coupled with the difficulties of the marine environment, means that energy from marine renewable sources will initially cost much more to produce than electricity produced by conventional fossil fuel based generation plants. In addition to the purchase cost, there is also the necessary cabling and beachhead connections to join the generators to the power grid.

It is hoped that the Islands will be able to benefit from the renewable energy generated by our tides and possibly receive an income through the supply of surplus electrical power via the subsea electrical cable that links the Island with Jersey and France.

There are a number of renewable energy options that may be applicable to Guernsey.

Tidal current devices - these extract energy from the flow of water, and often take the form of propellers or oscillating vanes fixed to a structure that is mounted on the seabed.

Wave energy devices - these take energy from waves. There are a number of types of device including buoy-type point absorber devices and near-shore or shallow water devices.

Offshore Wind - Guernsey has a significant wind energy resource and although areas of suitably shallow water off the west coast are limited there is sufficient area for small scale development. RET is currently looking at the mature technology of monopole turbine as floating turbines are still being developed. RET are contining ot monitor the progress of floating turbines as in the future there is the possibility of deploying these turbines off the west coast.

The above options are considered to be most suitable for Guernsey due to the geography of the region, and formed the focus of the Regional Environmental Assessment of Marine Energy. However, we will keep track of developments regarding other technology options for possible future use.

Tidal Barrages or Lagoons - RET are continuing to monitor progress in developments of tidal range options given recent progress including the ongoing process to develop Swansea Bay Tidal Lagoon. There are a number of bays, inlets and areas of shallow water around the coast of Guernsey. However, Guernsey's bays are quite small when looking at lagoons and this could have implications on providing commercial amounts of electricity without a substantive structure

RET will continue to monitor developments in all technologies to understand the potential options for Guernsey.