Will windfarms affect your cruising?
- Fri, 27 Apr 2012
Yachting Monthly's June issue features a report on offshore windfarms. Can you sail through them? Where are they being built? Our article guides you through the facts and the fiction surrounding this controversial topic. Here is some information and data we didn't have room for in the magazine
Offshore wind power is big business. There are 568 offshore wind turbines in UK waters and a further 665 in construction. Each turbine produces enough electricity annually to meet the consumption of 1,927 households. Just 11 years after the first turbines were installed in UK waters, offshore wind power already makes up around 1.5% of UK electricity production. This is expected to rise to 7.5% by 2016 and around 17% by 2020, roughly what the nuclear industry produces today. Reading such figures, it's hardly surprising to hear the UK is the world leader in offshore wind, with as much capacity installed as the rest of the world put together.
It seems counter-intuitive for yachtsmen to argue against the concept of harnessing wind power as part of the UK's ‘energy mix'. But serious concerns have been raised over cost, a feared threat to navigation, a risk of contact between turbine and mast, a potential impact on sea currents, on radar and more.
What is the history of offshore wind power?
The Danish were the first to install offshore turbines in the 1970s but the first applications for UK windfarms were made only in 1996. The Crown Estate owns almost all the UK coastline out to 12 nautical miles and had to agree to lease the seabed before construction could start.
Talks with fishermen, tourist boards, bird protection groups, the Coastguard, RYA and other interested parties were held by the British Wind Energy Association, which then formulated Best Practice Guidelines for offshore windfarm development.
The first project in UK waters was completed in 2001 in Blyth harbour, 10 miles from Newcastle. The first offshore wind farm in the UK, North Hoyle, off North Wales, was commissioned in December 2003 and the second, Scroby Sands, off Great Yarmouth, one year later in December 2004, followed by what was then the world's largest offshore wind farm, the Kentish Flats in 2005.
This was part of the so-called Round 1, consisting of 18 sites of up to 30 turbines around the coast. Round 2 has been running since 2008, with a host of new projects now nearing completion.
Round 3 will see proposals for extensions of existing windfarms and new sites built much further offshore, as technology has developed to allow turbines to be sunk in deeper water.
Interestingly, only European countries have developed offshore windfarms so far, although there are plans to build two on the East Coast of the USA.
How are the turbines sunk into the sea?
Most turbines are constructed on cylindrical steel tubes that are hammered or vibrated into the sea bed. Erosion protection is placed at the base to prevent damage to the sea floor.
Big windfarms have offshore substations to collect power from groups of turbines before feeding it to shore via undersea cables. Transformers boost the power to a higher voltage before it's brought ashore to reduce the amount of electricity lost during transmission.
Once the turbine is assembled, sensors on the turbine detect the wind direction and turn the head into the wind.
Do windfarms create jobs?
Denmark's largest offshore wind farm, Horns Rev 2, has revitalised the Port of Esbjerg, which had declined as a fishing port, and the signs are the same can happen in the UK.
Wells-next-the-Sea, in Norfolk, has seen increased harbour activity as the windfarms off Sheringham and in The Wash have been built. Port of Wells Harbourmaster Robert Smith told Yachting Monthly: ‘It's been a massive boost, not just to the harbour but to the whole of North Norfolk. The project started here three years ago and I had some concerns. The reason we went forward was because they said there'd be jobs created. True to their word, it has worked that way. Staff numbers at the harbour have gone from four to 12. We did our own study on the wider situation and found that about 85 jobs were created locally, from crews on the boats to office staff to taxi drivers. New businesses have started up, such as firms to test the lifting equipment. Even the local butchers and bakers are employing more people to cope with demand. There's a temporary hotel ship here housing some of the workers, but they're building a permanent base outside the town.'
London Array's construction is being managed from a temporary base, with up to 65 staff, at the Port of Ramsgate. Thanet District Council, which operates the Port of Ramsgate, said there had been a positive impact locally.
Rob Brown, Harbourmaster, Ramsgate Royal Harbour, said: ‘Many local people have been employed in both maintenance and construction management teams and it is within the projects' policies that they employ as many local staff as possible. In addition, many local contractors have worked with the windfarm companies including building contractors, fencing contractors, engineering contractors, support vessels, diving teams, ships chandlers and the harbour slipways - right the way through the supply chain to local taxi companies.
‘Hotels and bed & breakfast's in Ramsgate have had a high occupancy rate due to staff from the windfarm and their supply chain staff requiring local temporary accommodation. A large number of properties have also been let for both accommodation and office space. They are also supporting 10 University Bursaries for local people and apprenticeships locally with Thanet College.'
A dedicated website has been established to encourage and facilitate local supply chain, which can be viewed at www.kentwindenergy.co.uk
Overall, the number of people working in the UK's offshore wind sector has grown from 700 people in 2007, to around 3,200 in 2011.
A study completed for RenewableUK predicted that by 2020 an installed 31GW would create 42,400 full-time employees. As a comparison, the number of people currently employed in the nuclear industry is around 44,000.
Is there a fire risk?
There was a well-publicised fire in the gearbox of a turbine off Scotland last year, caused by a ‘mechanical malfunction'. The wind industry sees this as an isolated incident and points to the lack of problems in the operational 3,600-odd land and offshore turbines so far.
Do they create good fishing areas?
Some turbine foundations have become artificial reefs, with fish, crabs and lobsters attracted to the new food supply. Yachtsmen who are keen on fishing are advised to pay close attention to any exclusion zones around turbines as well as other safety factors.
What about sea birds?
Studies carried out, in conjuction with windfarm construction companies, on existing windfarms revealed no detrimental affect on bird populations in those areas. However the Royal Society for the Protection of Birds (RSPB) has raised objections to some sites and said: ‘The main concerns associated with offshore wind farms are collision, displacement from habitat or food resources, diversion of major flight routes, including those between feeding and breeding locations, as well as longer distance migrations, and especially the cumulative effects of these, either separately or in combination. The effects are highly species-specific, and consequently the risks may vary regionally.'
Story of a windfarm: London Array
Situated in the Thames estuary, this farm of 175 turbines should generate 1,000MW, powering between 480,000 and 750,000 homes across SE England and making it the world's largest consented offshore windfarm.
The London Array project started in 2001, when a series of environmental studies in the outer Thames Estuary confirmed the area would be a suitable windfarm site. The Crown Estate, owners of the seabed, gave London Array Ltd a 50-year lease for the site and the 450kms of cabling. Planning consent for a 1GW offshore wind farm was granted in 2006 and offshore construction started in March 2011 with the installation of the first foundations. The farm should be complete by April 2013. A second phase of turbines is planned thereafter to complete the project.
Three companies are building it:
Denmark-based DONG Energy, which has built around half of all windfarms in existence so far. They operate the windfarms at Gunfleet Sands off Essex, Burbo Bank in Liverpool Bay and the Walney and Barrows sites off Barrow in Furness.
E.ON Group, one of the world's largest power and gas companies, who have been investing in wind power since 1991. They now own and operate 22 wind farms in the UK including those off Scroby Sands, off Great Yarmouth, and the 60-turbine Robin Rigg farm in the Solway Firth.
Masdar, an unlikely proponent for windpower based in Abu Dhabi, home to 8% of global crude oil reserves but keen to demonstrate its responsibility as an oil producer by helping create a balance between fossil fuels and renewable energy.
Here are some useful links for those interested in reading more on the topic of offshore windfarms:
A website for those opposing the Navitus Bay wind farm proposal off the Isle of Wight
Results of an RYA survey on windfarms
An incredible image of what appears to be a windfarm generating its own fog
An interactive map of windfarms offshore
A PDF booklet summarising the latest statistics on energy production, consumption, prices and climate change in the UK
The Department of Energy and Climate Change website with links to wind energy information and information on other renewable energy sources
The British Wind Energy Association website
The website of the London Array development off Kent
The website of Dong UK, one of the big players in offshore wind energy
A website set up by Dong for the Burbo Bank windfarm off Liverpool. You'll find websites for many other windfarms on the same site