Energize Weekly, November 27, 2019
Wind speeds in the mid-latitudes have increased 7 percent since 2010, a welcomed boost for the wind power business, according to an international team of researchers.
Based on the increase in wind speed, the researchers calculated that a typical wind turbine receiving the global average increased winds would produce 17 percent more energy in 2017 than in 2010.
Using climate indices to project future wind speeds, which are expected to grow for another 10 years, the researchers predicted a 34 percent increase in output by 2024.
Still, while wind speeds are expected to increase over the next decade, after that they may slow again as part of the Earth’s natural cycle.
Since the 1980s, there had been a pattern of declining winds in the mid-latitude region – a phenomenon known as global terrestrial stilling.
The team, led by researchers at Princeton University, analyzed wind speed records from more than 1,400 weather stations between 1978 and 2017, with a focus on North America, Europe and Asia, which have growing wind power industries.
From 1978 to 2010, wind speeds were declining about 2.3 percent per decade. Then that sharply reversed with a 7 percent increase in speeds for the last decade.
The researchers looked only at regional averages, and it did not examine how the increase in wind speeds might affect the severity of storms, which have also been increasing.
The reversal in the trend is due to large-scale oscillations, or swings, in sea-surface temperatures, altering the way heat and pressure are distributed.
“This study demonstrated the global relationship between the oscillations and land-based wind speeds,” according to a statement from Princeton University.
The oscillations are driven by many factors including the uneven heating of the Earth’s surface in different regions, leading to increasing wind speeds.
“We predict that the increasing wind speed trend will continue for 10 years, but we also show that because this is caused by ocean-atmosphere oscillations, maybe a decade later it will reverse again,” Zhenzhong Zeng, an associate professor at the Southern University of Science and Technology in Shenzhen, China, who led the study when he was at Princeton, said in a statement.
Understanding the trends in wind speeds could be useful in planning for projects since the life span of turbines is now between 20 and 30 years, the researchers said.
