Solar energy is the renewable that's usually heralded as having the greatest potential to scale up to civilization-level production. But new research looking at the amount of wind energy available for harvest over our oceans is an exciting reminder that wind power needs to be part of the equation too.
In fact, according to the study recently published in the Proceedings of the National Academy of Sciences, there's enough energy over the oceans to power all of human civilization with wind alone, reports The Washington Post.
To harvest that power, we would need to cover enormous stretches of the sea with turbines, a monumental engineering feat that would also have real environmental consequences. So while actually powering human civilization with wind power alone is probably impractical, the study demonstrates that floating wind farms have an immense untapped potential.
“I would look at this as kind of a green light for that industry from a geophysical point of view,” said one of the study's researchers, Ken Caldeira of the Carnegie Institution for Science in Stanford, California.
The reason offshore wind power has so much more potential than land-based wind farms is that wind speeds can be as much as 70 percent higher over the sea. Part of that is because natural and human structures on land create friction that slows wind down, but researchers also found that wind over the ocean circulates from higher altitudes.
“Over land, the turbines are just sort of scraping the kinetic energy out of the lowest part of the atmosphere, whereas over the ocean, it’s depleting the kinetic energy out of most of the troposphere, or the lower part of the atmosphere,” explained Caldeira.
The study found that it would take a 3 million square kilometer wind installation over the ocean to provide all of humanity’s current power needs, or 18 terawatts. That's a lot of turbines; it would need to cover an area roughly the size of Greenland. Still, it's possible.
Such a theoretical Greenland-sized wind farm would capture so much energy that it would alter the climate of our planet. For example, parts of the Arctic could cool by as much as 13 degrees Celsius, according to some computer models. Obviously we wouldn't want to do that, but it means wind energy has a measured role to play if we want to power civilization with renewables alone.
One thing's for sure: this study further reinforces the idea that fossil fuels are unnecessary, so long as the correct investments in renewables are made.