New research from the Carnegie Institution for Science has highlighted the "considerable opportunity" of developing offshore wind in the open ocean, which could generate up to three to five times as much energy as wind farms on land.
"Are the winds so fast just because there is nothing out there to slow them down?" asks Ken Caldeira, co-author of the new study. Wind turbines on wind farms continuously convert kinetic energy from surface winds into electricity. "These wind turbines have a lot of moving parts which need to be maintained", he said.
The researchers said that the offshore wind power, however, would vary according to the seasons.
The collaborators used a climate model to compare the output of a real-life Kansas-based wind farm with a same-size theoretical one, which is located on the North Atlantic ocean.
In tapping into wind as an energy source, the United States has for decades lagged behind Europe and United Kingdom, which are home to the largest offshore wind farms in the world, including the London Array and the Netherlands' Gemini wind farm. Land-based turbines themselves slow the air reducing the amount of energy subsequent rows of turbines can generate.
Which raises the question, would wind farms over the ocean suffer these same constraints or would the atmosphere be able to move more energy downward over the ocean?
In the North Atlantic, in particular, the drag introduced by wind turbines would not slow down winds as much as they would on land. The rate of electricity generation in large wind farms containing multiple wind arrays is, therefore, constrained by the rate of kinetic energy replenishment from the atmosphere above.
However, this tremendous wind power is very seasonal. This contrast in surface warming along the US coast drives the frequent generation of cyclones or low-pressure systems, that cross the Atlantic and are very efficient in drawing the upper atmosphere's energy down to the height of the turbines.
According to their research, wind farms in the North Atlantic could provide sufficient energy to meet the entire planet's needs over winter.
This property of open ocean wind means operators could pack turbines closer together and generate more than 6W/mon average, the simulations found.
"Wind speeds over open ocean areas are often higher than those in the windiest areas over land, which has motivated a quest to develop technologies that could harvest wind energy in deep water environments".