Air Pollution Brakes Wind: Study Finds Aerosols Hamper Turbines and Reduce Rain
We know what burning fossil fuels does to warm the planet, but now research is showing that air pollution is actually slowing down wind speeds, hampering the effectiveness of wind farms themselves. A recent study from Stanford has shown how aerosol particles in the air slow the speed of surface winds (as much as 8% in California), reducing the power-generation potential of wind turbines. What’s more, these particles block sunshine and lead to reduced evaporation (meaning less precipitation) and also interfere with clouds’ ability to release rain.Mark Z. Jacobson, associate professor of civil and environmental engineering at Stanford University, along with the late Yoram Kaufman, a leading NASA scientist, analyzed satellite imagery of aerosol accumulations from China to California, wind speed data, and computer simulations to understand how these floating particles impact wind speeds. How it works: aerosols in the air reflect or absorb solar radiation. This causes a cooling of the surface air, reducing the vertical convection effect that connects surface-level winds with higher, faster-moving winds. This broken connection means slower air currents. Additionally, these slower winds also evaporate less moisture into the sky from bodies of water, leading to lower precipitation. The presence of aerosol particles in clouds also hinders precipitation, and can cause clouds to go for longer periods of time before releasing rain. Mark Jacobson has estimated that, together, these effects could lower California’s water supply by 2 to 5 percent.
The impacts of this phenomenon could be big, since the world’s biggest polluters are those that need viable clean energy solutions the most, China being perhaps the most obvious case in point. A study last year from the Earth Policy Institute found that wind power is now cheaper than conventional power in at lease two markets, Austin, Texas, and Colorado. Texas as a whole also recently passed California as the US’s wind power leader (California gets approx. 1.5% of its power from wind). The disruption of low-blowing winds, however, could interfere with the cost effectiveness of wind farms, and push up the price of clean power. ::Stanford Report