Tide could be answer to Isle of Wight's future energy needs

St Catherine’s Point is already famous for its lighthouse and meteorological observations, but it now looks set to make a name for itself in the business of renewable energy. The point, which lies 16 metres above sea level on the south side of the Isle of Wight, is being lined up as site to create an underwater turbine farm that would have the potential to power the island’s entire electricity supply and more.
The University of Southampton and the Isle of Wight Council are currently looking at the best way to cooperate on the project, which could see the island benefiting from tidal energy in five to 10 years time.
Professor A.S. Bahaj, of the University of Southampton’s School of Civil Engineering and the Environment Sustainable Energy Research Group, is a leading marine energy researcher and is heading up the project. He says the Isle of Wight offers an exciting opportunity to harness the power of the sea.
“Energy from marine currents is very predictable and offers electricity at a higher power density than other renewables,” he explains. “The velocity and speed of currents at this site off the Isle of Wight would have the capacity to produce a lot of power – enough to supply the island and beyond.”
It is already known that energy in marine currents, although generally diffuse, is concentrated where sea flows are channelled through constraining land mass, such as islands and straits and because of the regularity of tides, tidal power is available 24 hours, only falling at the turn of the tide. Over the past four years Professor Bahaj’s research department has been looking at the marine energy resources in the English Channel and has come up with some impressive findings using two or more marine current turbines, otherwise known as an ‘Array’.
He says, under plans being drawn up, St Catherine’s Point would become “an important demonstration site for a range of turbines”.
These are mostly at the prototype stage at the moment, he says, but as some marine current turbine developers are planning to have their first Array marketable within five years, it might not be much longer before they are being commercially operated.
“It is quite possible we could see marine current turbines generating the Isle of Wight’s electricity from 2012 onwards,” says Professor Bahaj.
Britain possesses the best marine energy resources in Europe. A barrage across the river Severn on its own could generate almost five per cent of electricity in Britain while a report by the UK’s Carbon Trust estimates that marine energy could provide 20 per cent of the nation’s electricity in the long term. Other studies estimate the marine energy sector could generate revenues of between £300 million and £900 million by 2020.
Marine tidal turbine technologies follow much the same lines as wind turbines, but due to the greater power in ocean currents, these devices can be much smaller and, according to their developers, less intrusive. It is claimed the slow rotation speed of the turbine blades is better for the environment too, causing minimal effect on marine creatures.
As a commercial source of renewable energy, however, marine power is still in its infancy. As Professor Bahaj points out renewable energy from marine currents is “10 years behind wind energy” and it took wind energy 20 years to become commercially viable.
It is still early days for the St Catherine’s Point marine energy project. “We still need to collect much more data on the depth and currents around this site. We then have to do the modelling for the site, do the deployment, get consent and then get a connection to the national grid,” explains Professor Bahaj.
Nevertheless, unlike other renewables before it there is a powerful factor driving the commercial development of this technology – climate change. The UK has already committed £25 million since 1999 towards the wave and tidal programme and the government has a Marine Renewables Deployment Fund worth £50 million. Now local government is embracing it too.
It would seem the tide is turning in favour of marine energy.The UK’s renewable energy sector is predicted to grow to between £15 billion and £19 billion by 2020. The government has put the UK on path to reduce C02 emissions by 60 per cent by 2050 and to derive at least 10 per cent of electricity from renewable sources by 2010. The Renewables Obligation is driving investment by requiring electricity suppliers to source an increasing percentage of electricity from renewable sources…