Research from the Carnegie Institution for Science, headquartered in Washington DC, USA, says that there is considerable opportunity for generating wind power in the open ocean, particularly the North Atlantic.
Anna Possner and Ken Caldeira, who carried out the research at Carnegie, found that because wind speeds are higher on average over ocean than over land, wind turbines in the open ocean could, in theory, intercept over five times as much energy as wind turbines over land. This presents an opportunity, but it is uncertain whether this higher average wind speed can be converted into increased electricity generation.
Most of the energy captured by large wind farms originates higher up in the atmosphere and is transported down to the surface where the turbines extract this energy. Other studies suggest that there is a maximum rate of electricity generation for land-based wind farms, and concluded that this maximum rate of energy extraction is limited by the rate at which energy is moved down from faster, higher up winds.
Possner and Caldeira used sophisticated modelling tools to compare the productivity of large Kansas wind farms to massive, theoretical open-ocean wind farms. They found that in some areas, ocean-based wind farms could generate at least three times as much power than land-based wind farms. They found that the drag introduced by wind turbines would not slow down winds as much as they would on land. This is largely due to the fact that large amounts of heat pour out of the North Atlantic and into the overlying atmosphere, especially during winter.
Possner said: “We found that giant ocean-based wind farms are able to tap into the energy of the winds throughout much of the atmosphere, whereas onshore wind farms remain constrained by the near-surface wind resources.”