A recent study from the Carnegie Institution for Science is suggesting that planetary winds pack enough power to energize our entire civilization — and by a significant margin. But in order for us to capture all this energy, say the researchers, we'll have to supplement traditional ground-based stations with atmospheric wind turbines.
The study, which was conducted by Kate Marvel, Ben Kravitz, and Ken Caldeira, compared the total amount of energy that could be extracted from both surface and high-altitude winds. The focus of their research was to determine the geophysical limits of energy extraction from the Earth's wind, disregarding such things as economic, social or environmental factors. In essence, they simply wanted to know how much potential energy exists in the winds for us to exploit.
And what they discovered was that there's a lot of energy out there; there's plenty of power in Earth's winds to be a primary source of near-zero-emission electric power.
But this energy cannot be extracted from the surface alone. Wind turbines are great — but they're not massively scalable. They create drag (or resistance), which results in momentum being removed from the winds. So, while adding more and more turbines would increase the amount of energy that could be extracted, there will eventually come a tipping point such that adding more turbines will not generate more electricity. Consequently, the research team had to consider all possible optimal areas from which power could be harvested from wind.
Atmospheric wind turbines, also called kite turbines, are not a new concept. Though still speculative, it's thought that they will work by being supported in the air without a tower, working in low or high altitudes. When airborne, the device will transmit extracted energy to the ground via a conductive tether.
According to the researcher's models, more than 400 terrawatts of power could be extracted from surface winds, and that 1,800 terrawatts could be generated from atmospheric winds. The researchers admit that such a massive allocation of both ground and atmospheric turbines will have "pronounced climatic consequences," but that uniformly distributed wind turbines will not substantially affect the Earth's climate. Specifically, they predict that a full-out distributed system would result in a 0.1 degree Celsius increase in zonal mean temperature, and about a 1% increase in global precipitation.
That said, given the presence of massively distributed wind turbines, it's very possible that the climate impacts predicted by the Carnegie team will be substantially offset by the subsequent reduction of carbon emitting energy sources.
And remarkably, given that current global energy demand is about 18 terrawatts, this would suggest that there is still plenty of room for growth. Near-surface winds could provide more than 20 times today's global power demand, while atmospheric wind turbines could potentially capture 100 times the current global power demand.
Read the entire study at Nature Climate Change.
Image via Joby Energy.