Getting energy from the desert: Can we cover the Sahara with solar panels?

The stark signs of climate change have forced the world to reflect more intensively than ever at access to green energy. A non-fossil-fuel-free energy source that produces minimal carbon emissions is essential to our long-term survival.

Let's consider some of the options available, is that possible?

Our power options

Nuclear power can be the answer, as it produces no carbon emissions. Unfortunately, not all countries can afford to build nuclear plants, as they require a lot of resources and create significant risks related to the possibility of nuclear accidents.

So what about wind turbines? They are a sustainable and clean source of energy, but these turbines can be quite noisy and can also pose a threat to the lives of local birds. In addition, the wind is not a reliable source, as it does not always blow.

Unfortunately solar power plants also have a similar problem. The sun does not always shine in the sky, and there are areas where sunlight is light or often cloudy. With that being mentioned, there is a solution to this... It's deserts! They are largely uninhabited and enjoy abundant sunlight.

So why not cover deserts like the Sahara with solar panels?

Advantages of solar power plants in the desert

According to German physicist Gerard Kness, deserts around the world receive solar energy in just six hours (173,000 terawatts), more than humans consume in one year. (Information source available)

The Sahara Desert in Africa covers an area of 9.2 million square kilometers and occupies 8% of the land area on Earth. If 1.2 percent of this desert – about 110,000 square kilometers – were covered with solar panels, it would be enough to meet the energy needs of the entire world.

In addition, rainfall in the desert is very low, with little or no cloud coverage, limited wildlife, and negligible human numbers. These qualities make the desert practically useless to any human attention. But one man's garbage can be another man's treasure, in which case it is the treasure of the entire world. This makes the Sahara Desert our best bet for a clean and sustainable source of solar energy. If so, is anyone working to achieve this?

Yes, there was someone working on it. In 2009, Desertec launched an initiative to supply Europe with solar energy generated in deserts. Shortly after its inception, however, the initiative began to suffer from failures due to problems of implementation, transportation and cost.

Solar panels can turn desert into green areas

Large-scale photovoltaic panels covering the Sahara Desert may be the solution to our electrical requirements, but they may also cause more problems for the environment.

A simulation study conducted by EC-Earth at a solar farm reveals the impact of the low Albedo illumination of the desert on the local ecosystem. Luminosity is the measurement of the part of solar energy that is reflected off the ground, measured on a scale from 0 (this indicates a highly absorbent surface) to 1 (this refers to a reflective surface).

The study suggests that if solar panels account for more than 20% of the Sahara's total area, this could lead to a vicious cycle of rising temperatures. The formation of a cover of solar panels on the surface of the desert changes the luminosity, as photovoltaics absorb solar radiation in order to generate energy. Solar photovoltaic panels therefore have less luminosity compared to desert sands that reflect sunlight.

However, solar panels do not convert the entire incident sunlight into electricity. Instead, part of the solar energy is converted into heat, which can change the local temperature. Hot solar panels cause surface air to overheat and convection currents to flow, which in turn causes the steam to condense into rain. Increased rainfall will therefore be a booster for vegetation growth, reducing brightness even more, as plants absorb sunlight better than sand.

Drought, hurricanes and melting sea ice

Solar panels could wreak havoc in other parts of the world as well, as if turning the hot sandy land of the Sahara Desert into green, rainy ground was not enough.

Simulations indicate an increase of about 1.5 ° C in local surface air temperature in scenarios where 20% of the floor area is covered with solar panels. Similarly, there will be an increase of about 2.5 ° C with 50% land coverage. Ultimately, both scenarios could lead to an increase in global temperatures through the atmosphere and currents in the oceans. Greater warming effects in the Arctic are expected to be seen in the second scenario. Warming in the polar region would cause sea level to rise due to melting sea ice.

Redistributing precipitation in the Sahara Desert and adjacent areas would reduce rainfall in the Amazon by 10-30%. This is roughly the same amount of additional rainfall that the Sahara desert will receive due to the low luminosity caused by solar photovoltaic panels. Low humidity, decreased steam condensation and precipitation will lead to dry-zone conditions in the Amazon.

To hammer the final nail into the coffin of the Desert Solar Farms Project, it would promote the evolution of tropical cyclones over North America and the coasts of East Asia.

Storage and transportation issues

Even if we overcome all the potentially catastrophic effects of desert solar farms, we will have to solve the logistical problems related to storing and transporting all that energy. We will need very large batteries to store the energy generated during the day in order to continue supplying power throughout the night. Each panel will need a single battery to output power uninterrupted throughout the day, which would almost double the total cost of the solar power plant.

And what about transportation? How will we be able to power the whole world from a solar power plant located in the middle of the desert? Currently, Africa is still lagging far behind in developing reliable electrical grids. Long-distance energy transmission via power lines also comes with a certain percentage of energy loss (up to 22.8%).

In addition, the African region is politically unstable, making large investments (such as a solar farm) in this region risky.

Do we really need to seize vast acres of desert land and disrupt the ecosystem in order to produce solar energy? In fact, although the idea of reaping large amounts of energy from desert solar plants may be typical, it is still too complex to turn into reality. In turn, we have the technology to enable our towns and cities to generate their own solar energy.

However, if this concept materializes, it will be a great achievement for the whole world, as it will allow us to reduce our dependence on fossil fuels and move towards a more sustainable future.