Is Desert-Based Solar a Good Idea?
This article explores the benefits of desert-based solar and some potential challenges and solutions associated with rolling out large-scale solar farms in the desert.
Desert-based solar energy has emerged as a promising solution for sustainable power generation. In fact, with a vast expanse of available land and abundant sunlight, hot deserts are arguably one of the best places on earth for solar energy production. Some suggest the sun's power in desert regions could store enough energy to provide power 24/7, despite the weather or time of day.
Desert solar farm. Image used courtesy of Unsplash
So, why haven’t we covered every inch of the desert with solar panels?
Deserts are defined by the amount of precipitation they receive (less than 25 cm a year). This means many areas can be labeled as ‘deserts,’ even if they aren't the hot, sand-covered areas we typically imagine. In fact, Antarctica is the world’s biggest desert and receives very little sunlight year-round.
However, for ease of explanation and unless stated otherwise, when we refer to deserts, we mean hot, sand-covered areas such as the Sahara. These deserts are the subject of much debate around suitability as centers for solar power.
Benefits of Desert-Based Solar Energy
Abundant Solar Resources
Hot deserts are located in the most sun-intensive areas of the globe, offering an abundant resource for producing solar power.
For example, on average, the Sahara Desert can get between 10 and 13 hours of sunlight daily, starkly contrasting areas with much milder climates, such as the UK, which only gets an average of 4.9 hours of sunlight daily.
In addition, the sun's radiation in desert areas is more intense than in other regions. The Sahara Desert can see insolation in the range of 2,500 to 2,800 kWh/m2, compared to the UK, which only sees around 750 to 1,000 kWh/m2, demonstrating just how abundant solar resources are in the desert in both intensity and availability than other parts of the world.
Availability of Unused Land
Although solar power is considered one of the easiest and most efficient renewable energy production methods, actual production is severely limited without the land required for panel installation.
Finding suitable land for solar panel installation is one of the biggest challenges in solar power growth. Luckily, there are several potential solutions, ranging from increased panel efficiency to floating solar arrays.
The vast land availability in the desert creates another opportunity to overcome this challenge.
Why? Because there is lots of it and little else it can be used for.
In fact, a massive 33% of the world's surface is covered by desert. By definition, this land receives less than 25cm (10 inches) of precipitation a year. This makes it far from ideal for manufacturing, residential living, or cultivation.
The environmental benefits of solar power are well-documented. Solar is likely to continue playing a huge role in the global shift from fossil fuels, which emit harmful gases, to more sustainable energy production methods.
Leveraging the benefits of solar energy production in the desert could be a huge step toward achieving this goal. In fact, covering just 1.2% of the Sahara Desert with solar panels could generate enough energy to power the world.
Finally, installing solar panels in the desert could be a great way to generate jobs and funnel money into desert-based communities. This is especially important in some desert areas where employment is difficult to come by.
Challenges and Solutions
Installing vast solar farms in any area of the world would greatly impact the local ecosystems – the same can be said for deserts. In these areas, the biggest likely impact would be increasing heat. This would occur due to the surface change, such as from sand to solar panels.
Sand has a high albedo effect. This means it reflects much of the sun's rays back into the atmosphere. On the other hand, solar panels have a low albedo effect, meaning they absorb a lot of the sun's rays (and heat).
This temperature rise could impact global temperatures when done on a large scale. In turn, this could have a catastrophic impact on temperature-sensitive areas such as the poles.
Ultimately, planning and mitigation strategies, such as carefully selecting installation sites and adopting advanced solar technologies, will help overcome this challenge.
Typical PV solar panels operate at their most efficient around 25 degrees Celsius. Yet most hot deserts will exceed this temperature, especially during daylight hours when the solar panels will be working to produce electricity.
For example, the Sahara desert averages 30 degrees Celsius and often reaches much higher temperatures.
One way to overcome this challenge is to use cooling technologies to keep panels working at their optimal temperature. However, these technologies are typically run using water, which is already scarce in desert regions.
New cooling and water preservation methods will be required to overcome this challenge.
Another major challenge associated with desert-based solar power generation is transmission. After all, generating all that power is useless if you cannot get it where it is needed.
In some cases, this is less of an issue. For example, where large populations are located in or near deserts (such as Las Vegas), it is likely that the grid would only need minor extensions to connect to large-scale solar farms.
However, many deserts are considerably more isolated. In these cases, long-distance transmission lines will be required to help move electricity to areas where it can be used.
Desert-Based Solar Summary
From increased sunlight hours and solar radiation to the vast availability of land, it is clear that there are several huge benefits to locating solar panels in hot desert regions. In fact, to reach ambitious emissions targets, desert-based solar is likely an absolute necessity for a fossil fuel-free future.
However, several large-scale challenges must be overcome to make this a reality. With a growing global focus on renewable energy technologies and large-scale investments, we will likely see desert solar becoming more common in the coming years.