Offshore wind installations are gathering pace worldwide leading to the need for reliable, accessible infrastructure to bring the generated power onshore and into the electricity grid. As a result, demand for offshore substations is booming, especially in Europe. Rystad Energy research and modelling shows that 137 substations will be installed offshore continental Europe this decade, requiring US$20 billion in total investment. Over 120 of these facilities will be installed between 2024 – 2030 at a cost of around US$18 billion. As such, annual spending on offshore substations will increase steadily through 2030, rising from an average of US$1.4 billion/y from 2015 – 2023, to a new high of US$8.4 billion in 2030.
Substations are crucial in the offshore wind industry as they collect power generated by wind turbines, increase the operating voltage and transmitting the power to shore. The primary electrical system of an offshore substation includes switchgears, transformers/converters, a reactive power compensation system and an earthing system. Offshore substations are particularly beneficial for projects over 200 MW in capacity and located more than 15 km from shore, as they help minimise power transmission losses. They are also valuable for other energy initiatives, such as electrifying offshore oil and gas production platforms.
The surge in substation developments is being fuelled by the increased scale of offshore wind projects and their distance from shore, with projects exceeding 1 GW of capacity requiring multiple substations. Many European countries have set ambitious offshore wind installation goals which are set to transform the continent into a hub for substation activity. Europe is set to install eight new offshore substations in 2024 alone, double last year’s number. This year, new offshore substations will be confined to wind projects located within 50 km of the coast. However, in the latter half of this decade we expect a notable uptick in offshore wind installations beyond the 50-km mark, driving more need for offshore substations.
“We will see a substantial increase in spending in the offshore substation market this decade. This is linked to growing installed capacity in Europe and will be further amplified when floating wind technology takes off. Floating wind turbines are situated far from shore, meaning we could see the first floating substations in the early 2030s,” said Petra Manuel, Senior Offshore Wind Analyst at Rystad Energy.
Offshore substations can be divided into two sub-components: the topside, which contains the main electrical power system, auxiliary systems and the topside housing; and the foundation, which holds the weight of the topside structure. Jackets – fixed to the seabed with piles at each leg – have been the preferred foundation concept for most offshore substations since they can support wider and larger structures. However, some projects have also used monopiles driven directly into the seabed.
An offshore substation’s topside can be large in terms of length and width and is much heavier than a wind turbine. Of the nearly 100 offshore substations installed in Europe between 2014 – 2016, jackets held an almost a 70% share, with monopiles accounting for less than one-quarter. Some of the substation foundation concepts to be used in 2025 and 2026 are not yet known, so Rystad has noted them as unspecified in its research.
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Energy Global's Summer 2024 issue
The Summer 2024 issue of Energy Global starts with a guest comment from Terrawatt on the streamlining of the permitting process in Italy, before moving on to a regional report from Frost & Sullivan on the energy landscape in Asia Pacific. This issue looks at key topics such as wind installation vessels, offshore wind turbine foundations, weather analysis, solar maintenance, and more!