Climate researchers have estimated that nearly 70% of renewable energy sources must come from harnessing the power of solar energy in order to meet a future world goal of 100% sustainability. With a figure this large, blueprints were drafted to turn vast amounts of the Sahara desert into a solar farm. The idea is lofty and it does sound good on paper; however, what are the larger implications of such a plan? Is turning the Sahara desert into a solar greenhouse really the best way to achieve a sustainable future?
Recently, further research by Benjamin Smith of Western Sydney University and Zhengyao Lu from Lund University in Sweden has revealed that this may not be the most environmentally safe decision, largely because of misconceptions surrounding how solar panels absorb and distribute energy.
Solar panels are flat, black surfaces that absorb sunlight. However, what is not commonly understood, is the amount of energy that can be converted into power vs. what is released by the panel as heat energy. Only about 15% of incoming light can be converted to electricity, while the rest is reflected or distributed back out as heat.
A widespread collection of solar panels, as the blueprint suggests, could actually affect the global climate by heating up the Sahara desert even further. Heat emitted by the solar panels will be significantly higher than that of the reflective desert sand they will be covering.
As the Sahara heats, the oceans bordering the desert will also undergo changes that will increase the amount of moist air that rises and condenses to create rain storms. As these storms blow into the desert, the geography of the region can ultimately change back into a life-bearing tropic.
A new, habitable Sahara? That doesn’t sound too bad…
Except, this does not come without cost to the rest of the planet. The global heat of the planet would rise as well, and even a small rise (like the projected 0.39°C for 50% panel coverage of the Sahara) will drastically affect the polar regions of the world. Melting ice caps will only further increase global warming and create more unforeseen effects.
Consider also the valuable nutrients that the dust blow-off from the Sahara gives to the Atlantic oceans and the Amazon. If the Sahara turns green, where would these nutrients come from?
While contemplating new solutions to our current energy crisis of depleting fossil fuels, the long-term implications are still something to be considered. Otherwise, we will set the cycle up to repeat for future generations. Sustainability is only sustainable if our planet can last with us. Is it time to pepper our deserts with solar panels, or should we consider other alternatives?