As the pressure to obtain energy from renewable resources as a way of reducing energy costs, securing supply and curbing carbon emissions increases, high on the agenda is tidal energy – harnessing the power of the tides to produce electricity.
Around the UK there are several tidal turbine projects underway most notably on the islands of Orkney and Islay and in the Pentland Firth, Scotland. One of the most ground-breaking schemes to the south of the UK though is happening in the powerful coastal waters around Alderney, the third-largest of the Channel Islands.
Alderney’s waters are regarded as one of the most accessible tidal power resources in Europe – tides rise and fall by as much as 20 feet, producing currents averaging 10mph capable of generating up to 3GW, enough electricity to power at least one million homes.
Since 2007 Alderney Renewable Energy Ltd. (ARE) has been exploring the potential for a small array of tidal turbines in Alderney’s waters. In 2008 ARE was granted an exclusive 65-year license by the island’s government, the States of Alderney (States), to explore and develop 50% of Alderney’s territorial waters, an area of around 50 square miles. The company then sold a 20% stake to OpenHydro, an Irish energy company specialising in tidal power technology. OpenHydro has demonstration tidal power projects in the Pentland Firth, Bay of Fundy, Nova Scotia, Canada and Paimpol, France.
Now all the hard work that has gone into research, business plan developments, sourcing investment and ongoing work with the States is bearing fruit. ARE is seeking to build and operate a tidal pumped storage system to begin producing power for Alderney. The system will consist of up to four seabed mounted tidal turbines (model still to be decided) of 1MW each 3km offshore in the Race (a fast flowing tidal race between Alderney and the French coast) and a pumped storage system with a seawater reservoir in Fort Albert a large ruined cliff top fort, one of several Victorian forts on the island.
Working with the local electricity board, power generated from the tidal turbines will be fed into the seawater pumps so the seawater reservoir will power a 2MW hydro turbine powering the generators supplying Alderney’s electricity demands.
Currently, as well as being reliant on conventionally generated electricity, Alderney is also heavily reliant on expensive imported oil and calor gas for heating and cooking purposes, so the power generated by the tidal turbine project will be a boon, capable of supplying Alderney’s present power demands, of which 90% will be from renewable energy, and soon - the objective is to have the system operational by 1st July 2012.
A full Environmental Impact Assessment (EIA) is currently underway, which is set to be completed by end-May 2011 involving local organisations like Alderney Wildlife Trust, the Alderney Society and outside consultants in order to assess any effect the project may have on the environment. Consideration is focused on marine life and seabed impact plus the effects on flora and fauna along the route of the pipeline, plus the impact on the structure and historical significance of Fort Albert. If all goes according to schedule the EIA should be completed by end-May 2011.
The project though still requires planning consent from the States for onshore works and marine operating consent from the Alderney Commission for Renewable Energy, who is independently assessing the project.
Funding will be provided by vendor financing during the construction phase, then after six months of successful power generation and approval by ARE’s vendors’ engineers a debt finance package will be put in place to replace the vendor financing scheme.
Future Developments: Although this is initially a small-scale project, ARE is already looking at the bigger picture. Alderney is in a unique position, as a Crown Dependency, it is not formally part of the UK or the EU, which opens up a number of routes to market but means it has been ineligible so far for government green incentives. However a recent EU ruling permitting any member state to obtain renewable energy from outside the EU should qualify ARE for government support.
Although currently there are no power cables to or from Alderney, ARE holds the right to export power to both the UK and France. After successfully lobbying both the UK and French governments ARE has developed advanced plans for cable connections to both these countries. ARE acquired 285 MW capacity into the French Grid in 2008 and 2GW capacity into the UK grid in 2010. Alderney’s peak electricity demand is only around 1.5MW so the electricity generated by tidal power in excess of this will be exported.
Alderney’s tidal resource therefore has the potential to become a major contributor in assisting the UK and France to achieve their stated 2020 renewable energy targets of 15% and 23% respectively. The French link would connect with two nuclear power stations boosting the amount of zero-carbon power available. “There is a big push in Europe for more interconnection”, said Paul Clark CEO of ARE speaking to SRIB.
As for Alderney the strategic benefits are significant, bringing about independence and security of energy supply, capping escalating energy costs, producing a revenue stream for the States on exported electricity and encouraging economic development on the island.
For further information, visit ARE website.