Renewable energy installations like wind turbines and solar farms are usually tasked with preventing changes to the environment, butthey may cause some environmental change of their own. published in the journal Science, building wind and solar farms in the Sahara desert can increase rainfall and make more plants grow.
Governments and energy providers around the world are increasingly turning to wind and solar power to generate electricity and to replace climate change-causing fossil fuels. But one group of researchers wondered how these power sources would affect the environment as they become more common. After all, filling the sky with turbine blades and covering the ground with solar panels is likely to changing things—at least a little bit.
To test the idea, the team used the Sahara desert as a testbed as its been the site of large renewable plants in the past. For this study the authors looked at what the desert would look like if it was covered substantially with wind turbines and solar panels. The researchers simulated the effects of around 79 terawatts of solar panels and 3 terawatts of wind turbines.
To put that number in perspective, the was slightly less than a tenth of a terawatt, so this research isn’t immediately relevant for today’s renewable installations. But it's a number not completely unconceivable in the far future.
They found that with enough solar panels and wind turbines, the atmosphere around the installations will heat up, both from wind turbines churning the air and from solar panels absorbing more sunlight. That increased ground temperature, combined with slower wind speeds thanks to the turbines. These conditions would then promote more rainfall.
According to the simulations, the net effect is that the Sahara could see twice as much rainfall with those renewable installations as it does now. While on average is a small increase, researchers believe those rains would fall in concentrated places, creating up to 20 inches more rain per year—a huge change with vast ecological ramifications.
In effect, humanity could terraform one of the most extreme climates on Earth just by harnessing the energy of the sun's rays and the world's winds.