High Winds: Extracting Wind Power from High Altitudes
As you drive down the highway these days, wind turbines off in the distance are a familiar sight, sprouting up from the landscape like so many oversized metal dandelions. Yet, how often do you see wind farms today with turbines that aren’t turning?
The downtime every wind farm experiences represents time not spent generating electricity. (According to the U.S. Energy Information Administration, over the course of 2016 wind farms in the U.S. operated at just 34.7% of their capacity — a number that includes both downtime for maintenance and days with insufficient wind.) In fact, the wind’s intermittency is probably the greatest downside to this otherwise free, clean, and abundant source of energy.
But it doesn’t have to be this way, say a cadre of technologists, engineers, and startup companies. Geothermal energy is an “always-on” source of power. In 2016, geothermal energy sites in the U.S. operated at 74.2% of their capacity. What if wind could somehow be made to approach geothermal-scale capacity?
Next-generation wind energy advocates point out that you only need to go one kilometer up into the sky to find winds that almost never stop blowing. According to a recent study, for instance, the entire world’s energy budget is a drop in the bucket compared to the wind energy found at high altitudes. The world consumes some 18 terawatts of power at any moment (source: IEA), and according to this study, extracting 18 terawatts of power from high-altitude winds would not make a noticeable difference to the world’s winds or climate.
Moreover, unlike conventional wind farms, where a few windy regions on Earth are the prime locations, potential airborne wind energy (AWE) sites are prevalent across the world. High-altitude winds blow more steadily, more powerfully, and more reliably nearly anywhere on Earth one might care to look.