Climate change is also the wind conditions change in many regions of the world. What consequences this could have for wind energy yields has now been determined by US researchers. Their forecast: By the end of this century, wind yields in the northern hemisphere could decrease. In some regions of the tropics and the southern hemisphere, however, the winds could increase significantly.
Wind energy is considered in addition to solar energy as a cornerstone of the energy transition and the phasing out fossil fuels. Especially in Europe and North America, more and more wind farms are created. "Worldwide, the installed cumulative capacity of wind turbines has increased since 2006 by an average of 22 percent per year," report Kristopher Karnauskas and his colleagues at the University of Colorado in Boulder. However, "The wind farms are usually designed assuming and constructed so that the amount of recoverable from the wind energy will remain approximately constant in the future," said the researchers. But even now show data that the global climate and therefore the climates and large airflows within the framework of anthropogenic climate change begin to change. Studies show for Europe, for example, that the wind is changeable: periods of recession become more frequent and longer, but just as well storms and strongly fluctuating wind conditions.
Less in the north, more in the south
How does climate change on the wind conditions worldwide and the proceeds of the wind will affect south? Karnauskas and his colleagues have now determined using ten current climate models. So they simulated the changes by the year 2100 at two different climate scenarios: a warming of about 2.5 or 4.8 degrees Celsius by the end of this century.
The result: projected to the wind yields could decrease to the northern hemisphere more in the second half of this century, in the southern hemisphere take it. "Particularly noteworthy and robust while the decreases in the central United States, the British Isles, the central and northern Asia and the north of the Middle East," the researchers report. They calculated a reduction of wind power by 2100 to 14 percent in the temperate climate scenario and by 18 percent largely unabated climate change for the central United States. In the southern hemisphere, however, some regions could benefit from a strong increase in the usable wind energy. Thus, the researchers predict a rise of up to 42 or 41 percent for the East of Brazil and Australia's northeast. "However, Europe is a big question mark," Karnauskas admits. "We have no idea what we will see there, because the trend in the region is just too uncertain."
Two different causes
The cause of the global scale, two-part development are two different mechanisms that come with increasing climate change to bear, as the researchers report. In the northern hemisphere, the disproportionately strong warming of the Arctic makes sure that the temperature gradient between the polar regions and the tropics is weakening. Thereby the differences in air pressure and therefore the driving forces of the winds is reduced. "These declines the wind occur in the United States, Japan and the Horn of Africa, especially in winter," says Karnauskas and his colleagues. In the southern hemisphere, however, climate change will cause the land heats up faster than the sea. Through this enhanced gradient and the wind between land and sea blows more often and stronger.
But what does this mean for the planning of wind plants? How to grant the researchers themselves, their data for a specific planning of future wind farms are much too rough - especially in complex terrain. For as much wind a plant can actually "harvest", is highly dependent on the location and its local conditions. Moreover, such a long-term prediction of wind income can not be more reliably, at least according to some climate experts. "I doubt very much that calculate with today's climate models yield of wind turbines more than 80 years in advance can," said Bruno Burger from the Fraunhofer Institute for Solar Energy Systems in Freiburg. According Karnauskas and his colleagues report their findings provide but at least a clue of where more detailed, local analysis of the coming wind conditions could be useful and necessary.