When it comes to harnessing renewable wind energy, the European Union is not even close to reaching its full potential, according to a new study.
If a wind turbine was placed on every suitable spot of land, research shows it could provide more than 100 times the wind energy currently produced on shore. Calculated at more than 11 million additional turbines, that would be enough to power the entire world between now and 2050.
"Obviously, we are not saying that we should install turbines in all the identified sites," says Benjamin Sovacool, an expert in energy policy at the University of Sussex.
"But the study does show the huge wind power potential right across Europe which needs to be harnessed if we're to avert a climate catastrophe."
Today, the EU is a leader in wind energy output, and together its onshore and offshore turbines make up nearly a third of the world's total wind capacity. The European Commission has promised that by 2050, at least 100,000 more wind turbines will be either updated or added.
But the new findings push the potential ceiling much higher, even when excluding offshore wind farms.
Going nation by nation, and using an advanced system of wind atlases, researchers sought to answer one critical question: How much wind power potential does Europe have?
Taking into account infrastructure, built up areas, and protected areas, the authors found suitable lands with favourable wind speeds in 46 percent of Europe's territory. That's almost 5 million square kilometres, and nearly 500 exajoules of power - about 70 more exajoules than the world will need in 2050.
To be clear, this estimate is wide-ranging. The research did not look at site-specific limitations, public acceptance, or whether the land was privately owned; it only highlighted the areas suitable for current wind technology. As such, the authors say it's just a guide for policy, not a blueprint for development.
Nevertheless, compared to previous estimates, this is one of the most detailed insights yet into Europe's future wind potential. Using advanced GIS data at national and sub-national levels, the authors have blown other estimates out of the water. In 2009, for instance, the European Environment Agency calculated an onshore wind potential three times smaller.
Apart from improved resolution, such a huge discrepancy may have to do with different definitions of 'suitable land' or new technology. In the ten years since the earlier report was published, wind power capacity has tripled across the US as prices drop and wind turbine efficiency improves.
A different study, published just last month by German researchers, estimates that wind farms can only be built on roughly a quarter of Europe's land. This is more similar to past estimates, but by taking new turbine technology into account, researchers have calculated a much greater wind energy output.
In the end, these studies are all hypothetical and they each come with their limitations. Yet despite the European Union's recent interest in wind power, it is clear that there is plenty more room for growth.
"Critics will no doubt argue that the naturally intermittent supply of wind makes onshore wind energy unsuitable to meet the global demand," says Peter Enevoldsen who researchers wind energy at Aarhus University.
"But even without accounting for developments in wind turbine technology in the upcoming decades, onshore wind power is the cheapest mature source of renewable energy."
The findings have been published in Energy Policy.