The talk about renewable energy is centred around its impact on global warming. Clean energy sources such as wind farms are key to tackling climate change. But recent research suggests something else. Global warming will significantly cut the power of the wind across northern mid-latitudes, including the US, the UK and the Mediterranean region. However, some places, including eastern Australia, will see winds pick up. It’s a first of its kind global study, which talks about the impact of temperature rise on wind energy. The research has found that there will be big changes by the end of the century in many of the places hosting large numbers of turbines. According to a new research published recently in the journal Nature Geoscience, climate change in the future might cause wind resources to decline across the Northern Hemisphere. These losses could be tempered by increases in wind power potential south of the equator under severe climate change scenarios. Wind farms have grown more than fivefold in the last decade and plunging costs have made them a key way of reducing carbon emissions from fossil fuel burning.
But in central US, for example, the power of the wind could fall by nearly a fifth. Though the findings don’t disqualify wind as a competitive source of renewable energy yet the researchers do suggest that energy planners should take the future climate into account when creating long-term strategies for renewables. Wind powers only about 3.7% of worldwide energy consumption as of now, but global wind power capacity is increasing rapidly. It is growing at about 20% a year. In the latest study, researchers used an international set of climate model outputs to assess changes in wind energy resources across the globe. The team then used a ‘power curve’ from the wind energy industry to convert predictions of global winds, density and temperature into an estimate of wind energy production potential. While not all of the climate models agreed on what the future will bring, substantial changes may be in store, especially a prominent asymmetry in wind power potential across the globe.
Losses of wind energy stretched from central US to the UK, Russia and Japan for both medium- and high-emissions scenarios. If carbon dioxide emissions continue at high levels, wind power resources may decrease in the Northern Hemisphere’s mid-latitudes and increase in the Southern Hemisphere and tropics by 2100. It’s already known that climate change can affect global wind patterns. One reason winds exist is because certain parts of the planet receive different levels of solar radiation. The result is varying levels of atmospheric pressure around the planet, which affects the way air flows from one place to another around the world. So scientists are well aware that changes in global temperatures may affect the flow of air around the planet. These changes in global temperatures, particularly those changes which are occurring faster in some regions, like the Arctic, than in others will have a bigger impact. They could have a big impact on the amount of power wind turbines are able to produce from the air flowing around them. For example, the American Midwest has several hundred wind farms with tens of thousands of wind turbines. The new research shows that wind power production in this area over the next 20 years would be similar to that of today, but that by the end of the century it could drop.
Conversely, the potential wind energy resources in north-eastern Australia could increase significantly due to the changes in the temperature. The reasons for these decreases and increases are not the same, however. Warmer temperatures in the Northern Hemisphere at the North Pole weaken the temperature difference between the cold north and warmer equator, and a smaller temperature gradient means slower winds in the northern mid-latitudes. Similar wind resource decreases could occur in Japan, Mongolia and the Mediterranean by the end of this century. The reason the coastal areas would see increased wind energy is that the world’s land is warming faster than the ocean and that difference is the energy source for those winds. The more the land warms, the more it increases the wind power in that area. In the northern mid-latitudes, however, the major driver of wind is the temperature difference between the Arctic and the tropics, and the Arctic is warming very rapidly, reducing that difference.
In a world which is constantly affected by global warming, harnessing more wind power in coming decades could be critical for countries trying to meet emission reduction standards set by the Paris Climate Agreement. In addition to North America, the team identified possible wind power reductions in Japan, Mongolia and the Mediterranean. This may be bad news for the Japanese, who are rapidly accelerating their wind power development. The new study results should help decision-makers across the globe to make informed decisions about where to invest in this technology.