A floating wind farm is exactly what it sounds like—an array of wind turbines on floating platforms instead of fixed foundations rooted to the seabed. Each floating platform is tethered to the seabed with mooring lines and anchors that prevent it from drifting off. Floating wind turbines are important because they can be installed in deep waters where much of the world’s wind energy lies.
To achieve net-zero greenhouse gas emissions in the world energy system by 2050 and avert the worst impacts of climate change, countries must deploy a wide range of low-carbon energy technologies. The International Energy Agency’s “Net Zero by 2050” report estimates that around 150 gigawatts (GW) of offshore wind capacity additions will be needed by 2050. That’s about 25 times as much capacity as the world has today. However, almost 99 percent of today’s capacity is fixed-bottom wind farms in waters less than 50 meters (m) deep. Floating wind farms have the potential to provide over half of the needed capacity in the coming decades, expanding development to areas with stronger, more consistent winds over deeper waters.
Figure 1: Floating wind turbine
Despite its promise, floating wind technology is expensive. The levelized cost of energy (LCOE) for commercial-scale floating projects was between $110 per megawatt hour ($110/MWh) to $175/MWh in 2019. But cost reductions could come quickly with technological innovations in turbine platforms and size. The National Renewable Energy Laboratory estimates that the LCOE for floating projects could fall to around $60/MWh by 2032, which would be competitive with fixed-bottom projects.
Floating wind platforms are engineering marvels, balancing building-sized wind turbines as tall as 800 feet with wingspans longer than the largest commercial jet. Three major types of floating platform have been used in demonstration projects: spar-buoys, semi-submersible, and tension leg platforms (shown from left to right in figure 2).
Figure 2: Floating turbine platforms