Green Energy: What’s in it for Guernsey? – A personal viewpoint by Dr Andrew Casebow, States Agriculture and Environment Adviser

June 16th, 2010 by Andrew Casebow

Guernsey has long had a name as a ‘green island’, largely due to its countryside, its farming and wildlife, but it is now gaining a name as a ‘green’ island in another sense, because it is developing renewable energy. But, with all the current interest in ‘green’ energy we need to ask some critical questions: what is the size of the resource and how will we regulate its development so that our environment is not spoiled and the island community gains from the development rather than just providing a money-making potential for developers. Why should we develop the resource at this time, who will pay and what is in it for us as an island community?

What is the resource?

It is estimated that the UK has about 50 % of Europe’s raw tidal energy resource. Most of the resource is situated in the inhospitable waters off the North of Scotland but 10% or more is available from the tidal flows around the Channel Islands.

The tidal resource can be considered in three ways: the theoretical energy that is in the force of the tides, the power that can be technically used to generate electricity and the power that can be economically produced given all the constraints. A Black and Veatch consultants report in 2004 estimated the Channel Islands technical resource at around 16 TWh/year (which is about 4% of UK supply).

The sea areas around Alderney have potentially the greatest resource of tidal energy in the Channel Islands. Guernsey and Sark have a good resource, particularly in the Big Russel, where strong currents flow over a relatively level seabed 40 metres below the surface, whilst there are also worthwhile areas to the East of Sark, in the Little Russel, around St Martin’s point and to the North West of Guernsey. Some areas could be developed using technology that is being developed now whilst other areas may only be worth exploiting when improved devices are available in the future, that can generate power efficiently from lower velocity streams.

Click image to expand

There are a number of different competing device designs, some of which will be the forerunners of commercial turbines in the future, whilst others may not stay the course. Some devices look like small wind turbines that stand on a pylon or tripod on the sea-bed, others, like the MCT Sea-Gen device, can be raised above the sea for maintenance, whilst others, such as the ‘Open-Hydro’ generator, appears to be like a jet-engine fan with an open centre. Whilst some, such as Sea-Gen, are surface piercing, others will work completely unseen in the depths. So far, they are all individual devices and the challenge now is to develop arrays, or a number of tidal generators that can work together. The challenge is also to design and build devices that will need less maintenance, thus making them cheaper to operate.

An important factor is the characteristic of the tidal stream itself. Tidal turbines need a strong ‘linear’ flow that flows for a long period in one direction before reversing (so that power can be generated as the tide flows in both directions) and is not turbulent, broken up as it courses around underwater rocks. In some areas the sea may flow strongly in one direction near the seabed but may even flow in the opposite direction nearer to the surface. Just think what this underwater turmoil will do to turbine blades!

Another factor is the strength of the flow itself. Really strong, or fast, tidal currents could be a problem at the present time, as it will be more difficult to install the equipment, to anchor it to the sea bed and, later, to service and maintain it. The laying of electrical cables across a rocky seabed in powerful tidal currents will also be a real challenge.

Some of the main power companies and turbine developers have already developed successful power turbines at heavily subsidised test sites in other areas, for instance at the European Marine Energy Centre (EMEC) in Orkney. Other turbines are being developed in the Bay of Fundy in Canada, in South Korea and in New Zealand.

The test sites have been specially developed to provide the additional support needed by these emerging technologies both for testing individual devices and for ‘first generation’ small commercial arrays. However, the devices have not yet been joined together to form a small array of devices. It is only when this next step is successfully accomplished that tidal generation might become economically viable.

Guernsey might be considered most suitable for the ‘second generation’ development of tidal arrays (30-50 of the 1MW generators), where local consumers might use the electricity produced. Such an array might produce up to 20% of the electricity that is used in Guernsey and electricity might be available for export. Such an array could be developed within a one square kilometre area of sea-bed or alternatively in a number of smaller 10 MW arrays. Later, larger tidal arrays could be developed that would provide electricity for export, if such a development was in our island’s best interests.

Guernsey has an advantage over other areas because the power generated could be used by island residents but it could also be exported as the island is already connected to the European grid. Guernsey is supplied with electricity from France, so theoretically it might be possible to export renewable electricity to France or Jersey from the outset.

Environmental and Social Assessment

The natural environment and the needs of other sea-users, such as fishing, shipping and pleasure boating, must also be considered when developing tidal energy.

Environmental constraints will be taken into account, such as the ecology of the seabed (some of which has never been seen because it is too deep for normal diving), the habitats and breeding of fish and crustaceans, and the effect on sea mammals.

A Scoping Report for a Regional Environmental Assessment of Tidal Energy in Guernsey and Sark territorial waters was published in 2009 and a full report that takes account of all these issues will be published for consultation in the coming weeks.

Commercial developers will also have to undertake a full Environmental Impact Assessment and monitor the effects of the tidal devices on wildlife and the natural world as a condition of being awarded a license to operate. Early suggestions are that seabed devices could provide a marine conservation area where fish can breed and marine plants and animals remain largely undisturbed. In short, a haven made for wildlife, fishermen and anglers alike.

The next step will then be to divide up the specific area of the sea-bed into zones to ensure that the most appropriate areas are developed. These may not necessarily be the best areas for tidal current, but the most appropriate areas when all other considerations have been taken into account. This might mean that the available resource is smaller than originally estimated.

The Renewable Energy Commission

It is important that everything is ‘put in place’ for future development of the resource and that Guernsey is recognised as a ‘good place to do business’. This is the work of the Guernsey Renewable Energy Commission (GREC) that was set up by the Commerce and Employment Department following the States Energy Debate in June 2008 and later authorised by the States in April 2009.

Richard Babbé, Chairman of the Commission, explains the huge amount of work that has been set in motion since the Commission was set up: “We are in the process of establishing a legislative framework, examining the environmental and social issues, and ensuring that we are commercially attractive to potential developers”.

There is an enormous amount of work to undertake in the next two years:

• Legislation must be prepared to officially set up the Commission and to put in place an appropriate and transparent licensing and consenting procedure.

• An agreement will need to be hammered out with The Crown Estate that owns the seabed around Guernsey (Alderney benefited by owning the seabed around that island).

• The Strategic Environmental Assessment of the area (that has been called a Regional Environmental Assessment as it takes into account just Guernsey and Sark Territorial Waters) will be completed, following a public consultation.

• The resources will need to be monitored and mapped so that the island does not ‘under-sell’ its best resources.

• Sea areas need to be officially zoned and potential developers attracted that will offer the best possible deal with the States and people of Sark and Guernsey.

From the outset the Commission has sought to ensure that potential development will be as streamlined and straightforward as possible. It has wished to cut through the ‘Red Tape’ that delays development in the UK and Europe, and provide a ‘one-stop-shop’ for developers.

Alongside the Commission an independent Guernsey Renewable Energy Forum has been set up to facilitate the development of renewable energy in the islands and it is members of the Forum that have been working on the Environmental Assessment of the sea areas around Guernsey (within the 3 mile territorial limit), using many of our own ‘home-grown’ knowledgeable experts rather than bringing in outside consultants.

Additionally, a Channel Island’s Renewable Energy Forum has recently been set up with members from Alderney, Guernsey, Sark and Jersey. This will allow coordinated discussions to take place with the UK Government where the islands can ‘speak with one voice’. It is hoped that this will lead to closer cooperation between the islands and, possibly, in time, lead towards the establishment of a licensing authority that might even have jurisdiction throughout the Channel Islands.

Financing the development

Tidal power will not be cheap to develop and will probably either need a subsidy or an increased ‘feed-in-tariff’ in the early years if it is to be economically viable, and a justifiable investment. However, as alternative forms of electricity generation become more expensive and perhaps less secure, renewable energy produced reliably from the tides and under our own control will appear cheaper. The development of tidal power for our own use will become ‘common sense’!

It must be accepted that the companies that will develop these resources on our behalf will only do so for profit. They will be taking a considerable risk in the early days of the development and so the profits that they make will need to be commensurate with the risks that they take. In the UK these developments are heavily subsidised but as yet we do not have access to these subsidies and the French ‘feed-in tariffs’ have not been set at a sufficiently high price to make the export of renewable electricity to France a viable opportunity. Hopefully this will all change.

It is known that some communities in the UK are becoming involved in the development of renewable energy and so will also share the profits generated. For instance, profits from the ownership (or a share) in a community wind turbine is funding the insulation of local dwelling houses and businesses. Perhaps a means could be found whereby the residents of Guernsey and Sark could own a share in the development of tidal power from our own territorial seas.


Developing a world-class marine energy industry in Guernsey is a long game and will require sustained support over many years, either in the form of subsidies or as an increased feed-in tariff for the electricity produced. However, renewable electricity will appear much more affordable as oil prices increase and, in time, Guernsey residents will be pleased to have their own secure supplies of renewable energy so that they are less dependent on more powerful neighbours.

The Guernsey Renewable Energy Commission is working hard to ensure that Guernsey remains a good place to do business and is not subject to the delays that can frustrate developers in other jurisdictions. However, renewable tidal energy is not a ‘bonanza’, certainly not in the foreseeable future. Guernsey is not the future Saudi Arabia of tidal energy, nor will electricity generation replace other industries within the island.


The theme of this month’s British Irish Council Meeting in Guernsey on 24th and 25th June will be ‘renewable energy’. A technical seminar on renewable energy will also take place in Guernsey on 24th June that has been jointly organised by the Guernsey Commerce and Employment Department and the Scottish Government.

The draft Regional Environmental Assessment will be published for consultation on the Guernsey Renewable Energy Commission website in June 2010.

  1. No Comments

Have your say