WHY DON’T WE COVER THE DESERT WITH SOLAR PANELS

Each day, the Sahara Desert experiences scorching temperatures reaching up to 80°C. Spanning approximately nine million square kilometers, this vast desert receives a staggering 22 million terawatt hours of energy from the Sun annually, surpassing humanity's total energy consumption by over 100 times. The question arises: could covering the desert with solar panels be the ultimate solution to our energy challenges?

Solar panels operate by capturing light particles that possess enough energy to dislodge electrons from their stable bonds, generating electricity during the electrons' return to stability. However, solar panels have limitations in their power generation capabilities. They can only interact with specific wavelengths of light, leaving over half of the sunlight they receive unusable. Moreover, even the light particles they can convert often bounce off the panels without triggering the electron-release process. Nonetheless, advancements in technology, driven by ingenious scientists, engineers, and substantial government investments, have led to significant improvements in solar panel efficiency.

Anti-reflective coatings and surface patterns on the panels now facilitate more efficient absorption of incoming light particles, enhancing commercial solar panel efficiency from low-teens to 25%, with experimental models reaching an impressive 47%. Additionally, solar power has become increasingly affordable, with costs plummeting by 89% in the last decade, partly due to global supply chains for other technologies that share similar materials. Consequently, solar power has become the most cost-effective source of electricity worldwide.

Several countries, including India, China, Egypt, and the US, have already established massive solar farms in the desert, spanning between 15 to 56 square kilometers. These solar farms provide energy to hundreds of thousands of local residents during peak sunlight hours. However, a challenge arises due to the intense heat experienced by these farms. The solar cells not converting or reflecting light absorb it as heat, leading to reduced panel efficiency. The cooling systems employed by these farms consume substantial amounts of energy, using fans or water movement to maintain optimal temperatures. Despite these efforts, solar panels in the desert still absorb more heat than the natural sandy environment. While this has not posed significant problems for existing solar farms, attempting to cover the entire Sahara with solar panels could potentially trigger extensive climate changes, transforming the desert landscape in unprecedented ways. The construction of such a massive solar plant could disrupt local ecosystems and the delicate balance of the region's climate.

Thankfully, solar panels are not the sole solution for harnessing the Sun's energy in the desert. Some of the world's largest solar plants have opted for an alternative approach, utilizing giant mirrors. For example, Morocco's Noor Power Plant, which is expected to cover around 30 square kilometers of the Sahara, employs a concentrated solar power design. This setup reflects light onto a receiver, converting it to heat and subsequently to electricity. Although these mirrors still result in a temperature shift that can be harmful to local wildlife, they have a reduced potential to transform the landscape. Furthermore, due to the time required for the heated materials to cool off, these plants can continue generating electricity beyond sunset.

Industrial solar farms, whether using panels or mirrors, can be easily integrated into existing energy infrastructure. However, the challenge lies in transmitting their electricity beyond local power grids, which is currently a complex task. Some countries are exploring ways to connect electric grids on a global scale. Additionally, many farms store surplus energy in large batteries or convert it into clean gas for future use. Nevertheless, these techniques are still relatively expensive and inefficient at present.

One drawback is that industrial renewable energy sources can encounter some of the same issues associated with fossil fuels, such as reliance on environmentally damaging mining operations and carbon-emitting global supply chains. Despite these challenges, solar power can be implemented on various scales, ranging from massive industrial solar farms to smaller installations that cater to individual buildings and rural communities. These projects can complement energy usage or serve as passive energy sources for regions lacking access to traditional power grids. One of the major advantages of solar panels is their flexibility, enabling quick installation and ease of updates. This adaptability has contributed significantly to solar power's widespread adoption and affordability over the past decade. In conclusion, to keep pace with humanity's increasing energy needs, a combination of large-scale and small-scale solutions will be required.