Fast Jet Stream Winds Do Not Contribute to Considerable Renewable Energy

Researchers of the Max Planck Institute for Biogeochemistry have challenged the notion that fast jet stream winds in the upper atmosphere contribute to high wind power.

The head of the ‘Biospheric Theory and Modelling’ group at Max Planck, Dr. Axel Kleidon, and his partners discovered that the maximum energy that can be extracted from jet streams is around 200 times lesser than what has been previously reported. They also showed from climate model simulations that when energy was extracted from jet streams, their flow was altered, which can affect the planet’s climate system.

Jet streams are caused due to difference in heating between the equatorial and the polar regions, which leads to huge variations in air and temperatures between the two regions, causing wind. Jet streams occur at altitudes of 7-16 km and have wind speeds more than 25 m/s. Though the speeds lead to the assumption that they may provide continuous power for all civilization, the differential heating controls the amount that can be used as an energy resource.

“Geostrophic flow” or very low friction causes high speeds of jet streams. The Coriolis force and the accelerating force that occurs due to the pressure differences cause this geostrophic flow. At such high altitudes, friction plays a minor role, and very little power is required for accelerating and sustaining the jet streams. Dr. Kleidon stated that the low power limited the usage of jet streams as an energy resource. The group estimated that a maximum of 7.5 TW can be derived, which was significantly less than what was previously estimated.

For extraction of energy, wind turbines have to add some drag to the flow of wind. The extraction will also cause a change or disruption in the natural balance of forces. This can slow down the climate system and also lead to extreme changes in the weather and temperature.