By converting wind energy into electricity, wind turbines reduce the environmental impact of power generation. The government is supporting further major expansion of offshore wind energy development, with the target of delivering 40GW of electricity generation by 2030.
Wind farms: onshore and offshore
Wind turbines can be deployed individually, to power a single site or installation, but are most commonly grouped together in an array as a ‘wind farm’ to provide power to the national grid.
In 2020 the government proposed updating its 2014 best-practice guidance for England on community benefits and engagement guidance for onshore wind. At the same time government put forward a set of proposals to amend the mechanism for supporting new, low carbon electricity generation projects. The next allocation round is expected in 2021, potentially resulting in a new phase of growth for onshore wind power.
The energy output from individual turbines has increased dramatically over the past decade especially those built offshore. As a result, turbine towers are becoming taller and the rotor diameter of the blades has more than doubled.
The design of offshore turbine infrastructure is also changing with a recent project using gravity base foundations which were built on the Tyne and then floated down river for installation at Blyth.
Their greater energy yield means that the number of turbines needed to produce a given amount of energy has been reduced by at least a factor of five, with construction of turbine arrays moving further offshore to utilise favourable wind conditions. It is therefore likely that new turbine array designs will be developed such as using floating structures.
It is also likely that more existing offshore wind farms will be expanded utilising larger turbine designs. As a result, the visual impression of offshore arrays and the continuing change introduced into the historic character of our seas will require detailed assessment as part of project evaluation. However, it is also likely to be the case that when seen from the land, fewer, but larger turbines will be needed to produce the same amount of energy.
As technical advances improve its cost effectiveness, offshore wind generation is beginning to play an increasingly important role in achieving renewable energy targets. The UK has the largest installed offshore wind capacity in the world, with The Crown Estate (responsible for leasing seabed areas for renewable energy developments) recently announcing the next round of proposed leases.
It is also recognised that the survey programmes conducted for offshore wind farm developments can reveal new information about the historic environment. In particular, through archaeological analysis it is possible to enhance our knowledge of submerged and buried prehistoric environments, as well as historic shipwrecks and aircraft lost at sea which can be effectively avoided during construction and operation of these 21st century energy generating facilities.