Wind farms lead to ‘significant’ decrease in soil moisture, study finds 

A new study has found that wind farms can have a “significant” impact on soil moisture, and aggravate the soil drying in grassland areas, with impacts on ecosystems.

The research, published in peer-reviewed journal, Science of the Total Environment, found that “wind farms significantly reduced soil moisture within the wind farms and in the upwind and downwind directions.”

The study focused on wind farms located in the grasslands of China, and researchers “analyzed changes in soil moisture in different wind directions and seasons and then judged the impacts of wind turbine operation on soil moisture”.

They called for a better understanding of the impacts of the huge turbines on the environment when building wind farms, saying that “wind energy is renewable and clean; however, the long-term operation of wind turbines can affect local climates.”

“Our research shows that the operation of wind turbines will cause significant drying of soil, and this drought effect differs significantly according to season and wind direction,” the research team led by Prof Gang Wang of the School of Resources and Environmental Engineering, at Ludong University in China, wrote.

“Our results show that 1) the soil moisture within wind farms decreases most significantly, with a decrease of 4.4 % observed; 2) in summer and autumn, the declines in soil moisture in the downwind direction are significantly greater than those in the upwind direction, with the opposite occurring in spring.”

They also said that: “Wind farms aggravate the soil drying in grassland areas, which may have impacts on grassland ecosystems. Therefore, when building wind farms, we need to better understand their impacts on the environment.”

An earlier study, from 2002, showed that a U.S. region with four of the the world’s largest wind farms showed an increase in land surface temperature that researchers connected to the effects of the turbines.

The paper, published in Nature Climate Change, used NASA satellite data to show “that an area of west-central Texas covered by four large wind farms warmed at a rate of 0.72 degrees Celsius per decade relative to nearby regions without wind farms.”

Scientists said that the “effect most likely caused by the turbulence in turbine wakes acting like fans to pull down warmer air from higher altitudes at night”, lead author Liming Zhou at the University of Albany, State University of New York, said.

However, Zhou added that the ‘warming is also considered a local effect, not one that would contribute to a larger global trend’.

The Irish government has been investing in wind energy since 1992. Subsidies and other state transfers in regard to renewable energy in the 2011 to 2020 period alone amounted to more than €1.3 billion according to the CSO.

“Wind is Ireland’s oil,” said Micheál Martin told Davos last year. “Certainly, by the mid-2030s we want to be exporting energy.”

Today, Eirgrid, the Independent Transmission System Operator, will host the country’s first auction for companies seeking to bid for the right to generate electricity from offshore wind farms and sell to market.

However, it was revealed this week that the auction might “unveil the world’s most expensive offshore wind prices” with consequences for the prices customers expect to pay.