Offshore wind energy has seen unprecedented growth in Europe over the past few years. According to the latest European Union Wind Eurobarometer, 2016 ended with mixed figures: although the Old Continent only added 1.412 megawatts of offshore wind capacity, which represents a drop compared to the more than 3.000 MW added the previous year, 2016 witnessed the largest economic investment in offshore wind energy ever recorded in a single year in Europe, reaching 18.200 billion euros, 40% more compared to 2015.
The European Union closed 2016 with a total installed capacity of 153.600 megawatts of wind power, both onshore and offshore, an increase of around 12.068 MW compared to the previous year. Germany remained the driving force of the European wind sector, adding 5.443 MW more to its total. Of these, 824,3 MW came from offshore installations, consolidating Germany as a true leader in offshore wind power.
The Gemini offshore wind farm , located in Dutch waters, was one of the highlights of 2016. This facility consists of 150 Siemens turbines, with a total capacity of 600 MW.
Other wind farms such as Gode Wind 1 and Gode Wind 2 were also connected in the same year off the German coast. Siemens supplied the turbines for both. These farms, together with Gemini, were the only offshore wind farms to be completed in 2016.
Accuracy in offshore wind data and analysis
The EurObserv'ER observatory has clarified certain points regarding its 2016 data. Its statistics do not include nearshore wind farms, i.e. those located close to the coast, because their behaviour is more similar to that of a land-based wind farm than an offshore one. An example cited by EurObserv'ER is the Westermeerwind wind farm in the Netherlands, with a capacity of 144 MW and located very close to the shore.
Disconnections and technological advances
Throughout 2016, there were also some notable decommissionings. Windfloat , a floating platform with a 2 MW wind turbine off the coast of Portugal, was decommissioned after five years of testing. These tests provided vital information for improving future designs of floating platforms. A 5 MW prototype in Hooksiel, Germany, was also decommissioned after completing its testing phase.
Offshore wind energy prospects
Expectations for the years after 2016 were quite optimistic. In fact, the 2017-2018 biennium was expected to present much more robust figures, and Eurobarometer reported that at the beginning of 2017 there were more than 4.800 MW of offshore wind projects under construction, with an additional 24.200 MW already authorised and 65.600 MW in the design phase.
According to WindEurope, investment in offshore wind projects in 2016 amounted to €18.200 billion, distributed across 11 projects that secured financing. This represented an increase of almost 40% compared to investments in the previous year.
The largest offshore wind farm in the world
The world's largest offshore wind farm is located off the coast of Kent, England. The London Array , inaugurated in 2013 by former British Prime Minister David Cameron, has an installed capacity of 630 MW, enough to power nearly half a million homes. Its developers hope to increase its capacity to 870 MW in a second phase, which is still awaiting approval.
The London Array is an exceptional example of how offshore wind energy can make a significant contribution to electricity supply. With 175 Vestas SWT-3.6MW-120 wind turbines spread over around 100 square kilometres, this park required an average of 450 kilometres of subsea cables to connect all the wind turbines to two offshore substations. From these stations, electricity is transported to land via high-voltage cables.
Installation and characteristics of the London Array wind turbines
The Vestas SWT-3.6MW-120 is the model used in the London Array. Each of the 175 wind turbines is 147 meters tall, with rotors 90 meters in diameter and blades 58,5 meters long. With a unit capacity of 3.6 MW per turbine, these giants are designed to withstand the harsh conditions of the North Sea.
For the installation of each wind turbine offshore, a grid of piles adapted to the characteristics of the seabed was used, with depths varying between 5 and 25 metres. The foundations are designed to support the weight of up to 225 tonnes of the wind turbine while lifting it above sea level.
New technologies and floating wind power
In addition to traditional installations anchored to the seabed, floating wind turbine technology has emerged as a viable solution for locations with great depths, such as the Spanish coast. Unlike fixed turbines, floating turbines can be installed in deeper waters, where the wind is stronger and more consistent. This technology is currently in the pre-commercial phase, but it is expected to become a competitive option in the coming decades.
Advances in the supply chain and market opportunities
As demand for offshore wind energy continues to rise, so does the need to develop a robust supply chain that can support the mass production of key components such as wind turbine blades, subsea cables and offshore substations.
In the European context, countries like Germany, Denmark, and the Netherlands have intensified their industrial production to meet the demand for offshore wind farms, which is expected to grow substantially in the coming years. According to estimates from the European Wind Energy Association (EWEA) , approximately 60 GW more capacity will need to be added by 2030 to meet the region's decarbonization targets.
The strong investment in infrastructure for the construction of marine parks and the manufacturing of components promises to continue growing, with special interest in floating technology, which will be key to the success of offshore wind in regions such as the Cantabrian Sea and the Mediterranean, where the depths are greater.