Wind energy has become one of the most developed and cost-effective renewable energy technologies. Offshore wind is now becoming a significant part of the energy mix as we move to low-carbon, sustainable energy supplies. With a wealth of natural resource and coastlines, the UK is the world's largest producer of offshore wind energy.
Increasing use of renewables
The UK is under pressure to increase use of renewable energy to help tackle climate change and secure future energy supplies.
We have an EU target to source 15% of our energy (electricity, heat and transport) from renewable sources by 2020.
Depending on the performance of transport and heat, this could require 40% of consumed electricity to come from renewables by 2020 (see Offshore Wind Power, Big Challenge, Big Opportunity: maximising the environmental, economic and security benefit, Carbon Trust, PDF 4MB).
Currently most European win power is generated in onshore wind farms, but offshore is a major growth opportunity for the renewables market. Offshore advantages include greater acceptance among the population, and stronger and more constant winds in coastal areas and at sea.
The Crown Estate owns UK territorial waters and has issued leases in 3 consecutive rounds, for offshore wind developments around the UK. Licences were awarded in nine Round 3 zones in seas around the UK, from the Moray Firth to the Irish Sea.
Once complete, the total generating capacity of offshore wind in UK waters will be approximately 47GW; in contrast, the existing fleet of UK nuclear power stations has a combined generating capacity of 9GW.
World's largest offshore wind farm
The world's largest operational offshore wind farm opened in Thanet, Kent, in September 2010.
Thanet's 300MW of capacity will boost UK offshore wind capacity by 30% and will produce on average enough electricity to supply more than 200,000 homes.
In the government's Comprehensive Spending Review, subsidies for wind power remained untouched, unlike many other sustainability initiatives.
The chancellor pledged a further £200 million for low-carbon technologies including offshore wind technology. A further £60 million will help finance the development of manufacturing bases and infrastructure at port sites to support the manufacture and installation of turbines for the Round 3 offshore wind programme.
This demonstrates support for the development of a UK-based supply chain for offshore wind, but the sum is small and thinly spread, and substantial private sector investment will also be required to make Round 3 more commercially viable.
The challenge facing the renewables sector is to reduce the cost per unit generation. Engineering for an offshore environment is especially complex and costs are therefore higher.
Logistical challenges are greater offshore, with the complexities of building in increasingly difficult locations, in deeper water and further from shore. Issues include technology, materials, infrastructure, logistics and long build times. For these reasons, driving down the costs will be a major challenge.