Environment & Sustainability

North Sea, the world offshore wind hub

With the new world’s largest offshore wind farm project in progress in East Anglia the North Sea seems to be set to keep its leading role in the development of one of the currently most powerful renewable energy technologies.

Today the North Sea hosts the world’s largest operating offshore wind farm, the UK farm named London Array, and although some large projects are planned in other parts of the world, in the next few years this world record will probably be broken by another UK offshore wind farm under construction nearby, namely the East Anglia project.

London Array

The world’s largest operating offshore wind farm, London Array, became fully operational in April 2013. With 630 MW of installed capacity it is located in the Greater Thames estuary, 12 miles north of the Kent coast and 12 miles south of Essex. The original consent for London Array was for a wind farm of up to 1 000 MW, 630 MW in Phase One and a further 370 MW in Phase Two. Phase Two construction was formally abandoned by the consortium behind London Array[1] in 2014 due to the technical challenges and the environmental uncertainties surrounding the site, especially potential impacts on birds, which would have required years to be completely assessed.

Based on the average load factor for offshore wind published by the Digest of United Kingdom Energy Statistics, equal to 34.88%, meaning more than 3000 hours per year, on average the London Array 630 MW wind farm should generate almost 2 TWh of green electricity per year.

East Anglia

ScottishPower Renewables, part of Iberdrola, is constructing the offshore wind farm that will probably take the place of London Array as the world’s largest operating offshore windfarm.

As reported in Table 1 the ScottishPower Renewables plan for the East Anglia sea region is made up of four very large wind farms, of which two are at an advanced implementation stage (ONE and THREE), while the other two are at an earlier stage of planning (ONE North and TWO).

The latest news from East Anglia projects are good ones, since on 7th August ScottishPower Renewables has received planning approval from the Secretary of State for Business, Energy and Industrial Strategy (BEIS), for the East Anglia THREE windfarm, which will allow for the installation of larger ‘next generation’ turbines, up to a tip height of 247 metres.

East Anglia ONE, which was granted a 119 £/MWh in the Contracts for Difference (CfD) auction process of the UK low carbon electricity generators support mechanism, is due to be fully operational in 2020. East Anglia THREE, if successful in future CfD auctions, should see construction starting in 2022, with the project up and running by 2025.

North Sea offshore wind in Europe…

According to WindEurope, the European wind industry association, at the end of 2016 the total offshore wind installed capacity in Europe was equal to 12.6 GW, and most this capacity belongs to UK and Germany (Table 2).

About 72% of the total installed offshore wind capacity in Europe is in the North Sea, 16% in the Irish Sea and 12% in the Baltic Sea.

The following infographic, taken from WindEurope[2] summarizes the main trends and data of offshore wind in Europe.

Regarding the 24.2 GW of planned and already consented medium term projects, the North Sea will remain the main region for offshore deployment, with more than 19 GW (78% of total consented capacity) planned, followed by the Baltic Sea (more than 3 GW, 14%), and by the Atlantic Ocean (1 GW already consented, but a further 3 GW capacity is expected once French projects receive full consent). In the Irish Sea the planned capacity (0.7 GW) is largely from the Walney Extension project, and whilst there are consented projects in the Mediterranean Sea no significant momentum is expected there before 2020 (0.3 GW in total).

… and in the World

The North Sea hegemony in the offshore wind installed capacity remains unchanged when looking at data from the Global Wind Energy Council (GWEC), the international trade association for the wind power industry.  GWEC statistics show that in 2016 only four non-European countries have deployed some offshore wind capacity.

  • China, with 1 627 MW in total at the end of 2016
  • Japan, with 60 MW in total at the end of 2016
  • South Korea, with 35 MW in total at the end of 2016
  • US, with 30 MW in total at the end of 2016

China. China is moving forward to support the development of national offshore wind farms, and, according to GWEC, the limited potential for onshore wind in the North and West regions is helping to push developers to move offshore. The 13th Five-Year-Plan on Energy Development set feed-in tariffs for offshore, nearshore and intertidal projects, and a target of 5 GW by 2020 for offshore wind. The 4C Offshore consultancy company “Global Offshore Map” reports 182 offshore wins projects for China, with many farms of some hundreds MW. Although few of those projects are fully commissioned and most are at the early stages of planning activities, the database shows a great potential and a great interest of Chinese industry for the offshore sector.

Japan. In Japan 2.5 GW are planned and under various stages of development. Notwithstanding the country great potential, and the fact that offshore wind could help Japan’s move away from nuclear power and fossil fuels, regulatory and grid barriers, such as long led times for environmental permits and local agreements, are preventing the sector taking off. The Japan Wind Power Association envisages 10 GW of offshore capacity by 2030, including 4 GW of floating capacity.

US. Maybe surprisingly, offshore windfarms are a brand new reality for the US, where the first offshore project was commissioned in December 2016 off the coast of Rhode Island. A 400-600 MW project offshore New York seems to be on the way, and in total 13 projects on both coasts and in Great Lakes are currently planned, The US Department of Energy “Wind Vision” foresees offshore wind providing 2% of US electricity demand by 2030 and 7% by 2050.

New Players? In March 2017 the first two turbines of the Taiwanese 128 MW Formosa 1 project came online, and the commissioning should be completed by 2019. In India a consortium led by GWEC is implementing the Facilitating Offshore Wind in India (FOWIND) project, falling under the Indo-European co-operation on Renewable Energy Program and founded through a grant from the European Union. In Vietnam the 99.2 MW Bac Lieu near-shore wind farm in the Mekong Delta region has recently became fully operational; in the past few years the Vietnamese wind market stated to attract world turbine manufactures and investors, and with the correct regulatory and financial conditions the country could become a gigawatt sized wind market in Asia.

Bigger and bigger intermittent generators…

The largest existing offshore wind farms have a total installed capacity of some hundred megawatts, and some under construction or planned ones should exceed the one gigawatt threshold. Such sizes are comparable to medium/big fossil fueled thermal power plants, or to nuclear power reactors.

Nevertheless, average load factors are not that much comparable. Offshore wind generation (as all intermittent renewable sources) depends on the geographical-meteorological conditions, such as wind persistence and speed, so that, as mentioned above, offshore wind in UK is assumed to have a load factor of about 3000 hours per year. Modern and properly working thermal and nuclear power plants (excluding peaker and reserve power plants) typical load factors range between 60%-80%, which means 5000-7000 hours per year… assuming smooth fuel supply conditions, and without considering the geopolitical risks associated with fossil fuels markets.

… in a new and incresingly complex power system

Large scale offshore wind farms are one of many pillars the new electric power systems and markets architecture. Today most of them are or are planned to be built in the North Sea, but in many countries all over the world they are deemed to have an increasing role in the future electricity generation mix. Taking into consideration all the pros and cons, all the limits, risks, strengths and weaknesses of the variety of technologies and energy sources available in order to set up a reliable, balanced and resilient system will probably the trickiest and pivotal task of policy makers and leaders.


[1] La Caisse de dépôt et placement du Québec, a financial institution managing funds primarily for Québec’s public- and parapublic-sector pension and insurance plans (25%); DONG Energy, the Denmark-based European energy group procuring, producing, distributing and trading energy and related products across Northern Europe (25%); E.ON, the international, privately-owned energy supplier and one of the leading green energy supplier in the UK (30%); Masdar, the Abu Dhabi’s renewable energy company, backed by the Mubadala Development Company PJSC, the strategic investment company of the government of Abu Dhabi (20%). DONG Energy is the service provider of O&M services to London Array.

[2] https://windeurope.org/wp-content/uploads/files/about-wind/statistics/WindEurope-Annual-Offshore-Statistics-2016-Infographic.pdf