The world’s first wind farm was sited in New Hampshire in 1980, but it was not until 1991 that the first offshore wind farm was installed in Denmark. Since then around 40 offshore wind farms have been located in the waters off Belgium, Denmark, Finland, Germany, Ireland, the Netherlands, Norway, Sweden and the United Kingdom. The UK has 13 of these in operation including the 2 largest in the world at Walney and Thanet, a further 7 under construction and 5 with planning consent, making it the world leader in offshore wind. It has more capacity of offshore wind power that the rest of the world combined. Only European countries have developed wind power so far although Canada and the United States have various projects under development.
Why Offshore?
- Offshore wind farms take advantage of strong winds blowing over the surface of the sea. As water (especially deep water) has less surface roughness than land, the average wind speed is normally considerably higher over open water so their capacity is higher than a comparable land based wind farm.
- Offshore breezes are frequently stronger in the afternoon, the time when there is an increased use of electricity.
- Offshore wind power makes up around 1.5% of UK electricity production and is expected to rise to 17% by 2020 which is approximately what the nuclear industry now produces.
- It claims to reduce energy imports, air pollution and greenhouse gases, as well as meeting renewable electricity standards.
- Offshore wind turbines are less obtrusive than turbines on land, as their size is moderated by distance and their noise should not cause a nuisance. Building clusters of turbines reduces their visual impact which is one of the biggest objections to wind farms.
- They can often be sited close to big coastal cities where demand is high, reducing the need for new overland transmission lines. The signs are that towns and harbours nearest to the wind farms will experience increased trade and job opportunities. This is already evident in some places, as for example Wells-next-the-Sea in Norfolk and in Belfast the harbour is being redeveloped for a proposed £50m project, expected to create 150 jobs in construction, as well as hundreds more in the quarrying industry to obtain the 1m tonnes of stone needed from local quarries.
- The foundations of offshore wind farms can act as artificial reefs, increasing fish populations from this new food supply, but these increases may also encourage bird populations in the area which could result in collisions with the towers and rotor blades.
The case against
On the other hand, installation, service and maintenance of offshore wind farms are much more of a challenge than for those based on land. They are more expensive in all these areas and bad weather can stop work. Added to this, there are reports that some wind turbines around the UK are sinking into the sea because their foundations are suffering from subsidence. Some have been found to have this damage and others are being checked.
Wind farms do not, unfortunately, reduce the need for power stations, as the power they generate cannot be stored on a large scale, so we still need to generate power when wind is light or when demand exceeds supply.
Besides being a potential collision danger to birds, turbines may also cause them navigational disorientation, when the towers are lit. It is also feared that some species may be disorientated by the electromagnetic fields created by the electric cables and the underwater noises and vibrations.
The Implications for Boaters
Wind farms are certainly changing the appearance of many parts of our seas, but are they dangerous and should we protest against them?
With regard to navigating close to wind turbines, it is recommended that boats have a clearance of 4m below chart datum and there is usually no rule to prevent boats passing through a wind farm. There are exceptions, such as the Greater Gabbard, off Suffolk and the London Array, off Kent, which have exclusion zones around them, also all vessels are required to stay at least 500m from wind farms under construction and from wind farm vessels.
The rotating blades of a wind turbine should not be a danger unless a yacht with an extremely tall mast sailed nearer than was sensible and there is no record of such an incident.
There is no evidence that wind farms alter the strength or the direction of the wind, except for a few metres around each turbine and they are not believed to create dangerous turbulence. Neither do they affect tidal streams or sea state. In fact before construction starts it has to be proved that there will be no disturbance of natural processes once the site is operating.
What the critics say
In spite of the lack of evidence that wind farms will negatively affect boating there is still a huge amount of criticism from sailors and organisations.
- The proposed Navitus Bay Wind Park off the Isle of Wight is a concern for many local sailing clubs, including the Cowes-based Royal Yacht Squadron. This £3 billion wind farm is likely to cover 77 square miles in an area of dense leisure boat traffic and it is this huge scale of the project that is causing the main concern. Those against the scheme claim that there is no evidence available about the effect on radar or GPS, any craft suffering engine failure could be swept onto a turbine in a strong tide and there would be grave danger to boats navigating the area in fog. They fear that the wind farm could impact on the main sailing route from the Solent to the South East as well as the famous Fastnet Race which starts in Cowes. Others ask why a Dutch company should be building the wind farm rather than a UK organisation.
- The RYA and MCA are doing a lot to campaign on behalf of sailors who object to the schemes. They have been successful in protesting against the proposed 50m exclusion zone in the Thanet wind farm off Kent.
- Some MPs argue that the Government’s heavy subsidies supporting wind farms will result in higher household energy bills.
- Many argue that as offshore turbines have a lifespan of only 20-25 years after which they will probably be decommissioned or renewed, they are not worth the huge cost of building them.
- Environmentalists argue that wind farms pose a substantial danger to wildlife.
In conclusion
It seems that wind farms are here to stay and are likely to increase greatly in numbers, until a more acceptable and efficient way is found to create electricity. It is difficult for us to make a rational decision fore or against when there is so little evidence to inform us about any potential short or long term effects. Let us just hope that the powers that be are sympathetic to those of us using the seas and let us support those working on our behalf, such as the RYA and MCA, to make sure that the turbines are located where they will have the least detrimental effect to boating and the environment in general.
Author – Dee White