Atlantic wind farms could provide 'civilization-scale power'
This is the result of a chain of cause and effect originated by the thermal energy contained in the seawater that Atlantic currents transport north during the winter. Wind speeds are, on average, much higher over ocean than they are over land, which means that theoretically wind farms in the open ocean could capture five times more energy than wind farms on land.
As expected, the results showed a significant gap between land-based and sea-based wind energy. The energy that turbines tap into starts as faster winds at higher altitudes, which are brought down towards the surface.
Finally, wind turbines need to be created to withstand high wind speeds. In recent years, a growing body of research argues that the rate of generated power is limited to around 1.5 W m within large wind farms.
The two authors of the study Anna Possnera and Ken Caldeira, from the Carnegie Institution for Science in Stanford, California, said that the new research is a kind of green light for the wind energy industry from a geophysical point of view. This presents an enticing opportunity for generating renewable energy through wind turbines.
The study used computer models which compared the total output of huge onshore wind farms in Kansas with the potential output of an equivalent-sized wind farm floating in the Atlantic ocean.
"The real question is can the atmosphere over the ocean move more energy downward than the atmosphere over land is able to?"
Power generation from a giant North Atlantic wind farm would be seasonal, dropping significantly during the northern hemisphere summer.
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 researchers found. Land or close-to-shore farms merely "scrape" energy from the lowest level of the atmosphere, said Caldeira; open ocean installations could "tap into the kinetic energy reservoir of the entire overlying troposphere", he claimed. This heats air and causes it to rise, which leads to low pressure cyclones that force the efficient transfer of kinetic energy from the upper atmosphere to the surface of the ocean. What they found is that certain parts of the open ocean provide "considerably higher power generation rates".
While open water wind turbines are still very much in their infancy, there is hope that this research will provide strong incentives for companies to start developing the technology at a faster rate.