Offshore wind is gaining increasing ground as a source of clean, renewable, cost-efficient energy. It already has a strong foothold in Europe with around 15 GW installed capacity, and a global potential to reach more than 100 GW by 2030. However, bottom-fixed installations can only be installed in water depths of up to 60 m. Globally, close to 80 per cent of the resource potential for offshore wind is in deeper waters, where floating wind turbines such as Hywind are the only alternative.
The pilot wind farm Hywind Scotland is a gamechanger. The 30 MW wind farm is located 25 km offshore Peterhead and consists of five large wind turbines, each fixed to the seabed using suction anchors that will keep the turbines close to their original position. The turbines are located at water depths of 95–120 m in an area with an average wind speed of 10 metres per second. The wind farm will provide clean energy to over 22 000 homes in the UK. Hywind Scotland is producing electricity well above expectations and has withstood its first storm.
Development is costly. However, there have been significant cost reductions in both onshore and bottom-fixed offshore wind technologies in recent years, and floating wind is expected to follow a similar pattern over the next decade. The ambition is to cut the costs of energy generated by Hywind floating wind farms to EUR 40–60/MWh by 2030, a level similar to that of other renewable energy sources.
Hywind has been a journey of exploration, discovery and development, taking 16 years from an initial idea sketched on a napkin by two Equinor (formerly Statoil) employees to the opening of Hywind Scotland in 2017. Today, the technology owner, developer and operator Equinor has two clear ambitions for the years ahead: to lead floating wind to industrial scale by 2030 and to develop Hywind as the most cost-competitive concept. The next large-scale Hywind project is already underway.
Most of the world’s oceans have deep waters. Hywind floating offshore wind farms can be located in areas that were previously unsuitable for offshore wind, with technology that allows for installation at depths of up to 800 m and that can withstand 20-m-high waves.
Placement of floating turbines farther out to sea also minimises impact on the coastal environment and coastal marine life, which is sometimes a challenge in relation to conventional wind farms located closer to shore.
The global potential of offshore wind is currently 100 GW by 2030. Of this, floating offshore wind is estimated to constitute 10 per cent of the market, potentially powering 12 million homes in 2030. Eighty per cent of the global resource potential for offshore wind is found in deeper waters.
Photo: Jan Arne Wold.