Where Is Solar Energy Most Intense On Earth?

Solar energy is produced from the sun’s electromagnetic radiation and is a renewable energy source. The amount of solar energy that reaches the Earth’s surface varies widely based on location. This is because solar intensity depends on factors like a region’s latitude, altitude, cloud cover, and local climate. Understanding where the most intense solar energy regions are on Earth is key for effective solar power generation. This article will examine the areas around the globe that receive the highest levels of solar irradiation.

Equator Region

Solar intensity is highest near the equator because that is where the sun’s rays strike the Earth most directly. At the equator, the sun is directly overhead at noon throughout the year, meaning the solar rays have the shortest distance to travel through the atmosphere and the least atmosphere to pass through compared to anywhere else on Earth. This means the solar energy at the equator experiences less scattering and absorption from atmospheric gases and particles before reaching the planet’s surface. The sun’s rays are concentrated into a smaller area at the equator as well, further intensifying the solar energy. The combination of more direct overhead sunlight with less atmospheric interference results in the highest levels of solar irradiance on the planet being found within the tropics near the equator.

Deserts

Deserts, especially in subtropical regions, tend to receive the most intense solar radiation on Earth. This is due to consistently clear skies and a lack of cloud cover or rainfall. The hotter and drier the desert climate, the fewer clouds, and thus less diffuse solar radiation. Direct beam radiation is therefore highest in arid deserts.

The Sahara Desert in North Africa, for example, receives over 90% direct normal irradiance, meaning 90% of the sun’s radiation reaches the surface in a direct beam from the sun. This results in solar potential of over 2600 kWh/m2. Other leading deserts include the Sonoran Desert in the southwestern United States and northern Mexico at over 2800 kWh/m2, the deserts of Chile such as the Atacama Desert with totals above 3000 kWh/m2, and the deserts of the Middle East and Australia which also commonly exceed 2800 kWh/m2.

With very little moisture in the air to absorb or reflect sunlight, cloudless skies around 70% of the time, and surface reflectivity under 20%, solar radiation is consistently at peak levels in the world’s hot deserts. This makes them prime regions for solar power generation. Concentrated solar thermal plants and photovoltaic solar farms are increasingly common sights in deserts nowadays.

Altitude

Higher altitude regions often receive more intense sunlight due to less atmospheric filtering. As sunlight passes through the atmosphere, some of it gets scattered and absorbed by air molecules and particulates. This filtering effect is most pronounced at lower altitudes where the air is thicker. At higher altitudes, there is less air between the sun and the ground, resulting in less scattering and absorption.

For example, a location at sea level may receive around 1000 W/m2 of solar radiation at noon on a sunny day. But a location at 5000 feet (1500 meters) altitude may receive around 1100 W/m2 at the same time, a 10% increase. This difference adds up over the course of a day.

High plateaus and mountain peaks therefore tend to have excellent solar resources. The Andes Mountains in Chile, the Tibetan Plateau in Asia, the Rocky Mountains in the U.S., and the mountains of central Mexico all benefit from extra intense sunlight at high altitudes.

Chile

Chile’s Atacama Desert has emerged as an ideal location for solar power generation due to its extremely arid climate, high altitude, and proximity to the equator. The Atacama receives intense sunlight year-round and has cloudless skies over 80% of the time. With some areas receiving over 3,500 hours of sunshine per year, the solar irradiation in Chile’s northern deserts ranks among the highest worldwide.

The Atacama Desert sits on the western side of the Andes mountains, with elevations over 2,300 meters above sea level. At higher altitudes, sunlight passes through less atmosphere resulting in more intense radiation at the surface. Chile’s northern regions also benefit from being close to the equator, where the sun strikes the Earth most directly.

Major solar investments are underway in the Atacama taking advantage of these favorable conditions. Chile had just 70MW of solar power in 2013, but capacity is expected to reach 3,000MW by 2022. Large-scale solar farms are being built in the desert to meet Chile’s fast-growing electricity demands and position the country as a renewable energy exporter.

Southwestern United States

The southwestern United States, including states like California, Nevada, Arizona, New Mexico, and Texas, has excellent solar energy potential. This is largely due to the presence of major deserts like the Mojave Desert in California and Nevada, the Sonoran Desert in Arizona and California, and the Chihuahuan Desert in Texas, New Mexico, and Mexico.

The Mojave Desert, for example, receives up to 7 kWh/m2/day of solar radiation in areas like Daggett, California. This intensity of solar radiation is similar to some of the sunniest deserts in the world, like the Sahara and the Atacama Desert in Chile. The combination of clear skies, elevation, and minimal cloud cover creates ideal conditions for solar energy projects.

California leads the nation in solar energy capacity, thanks in large part to abundant solar resources in the Mojave Desert and other southwestern deserts. Large-scale solar installations like the Ivanpah Solar Electric Generating System in the Mojave Desert and solar photovoltaic power stations in the Imperial Valley desert demonstrate the productivity of solar energy in this region.

Sahara Desert

The Sahara Desert, located in Northern Africa, is the world’s largest hot desert and one of the sunniest places on Earth. With an area of over 3.5 million square miles, the Sahara receives copious amounts of solar irradiation due to its low latitude near the equator and consistently clear, cloudless skies. Solar insolation in the central Sahara can exceed 2,500 kWh/m2 per year which makes it even sunnier than most deserts.

Studies have shown that the solar potential across the Sahara is absolutely staggering. Researchers estimate that the Sahara Desert could potentially produce as much as 7,000 GW of solar power capacity, or 70 times the electricity generation capacity of the entire African continent today. Covering just a small fraction of the Sahara with solar panels could provide enough clean renewable electricity to power Europe several times over. With its vast size and intense sunlight, the Sahara represents one of the most promising locations on Earth for large-scale solar power installations.

Middle East

The Middle East region possesses some of the world’s best solar resources due to its arid desert climate. Countries like Saudi Arabia, UAE, and Qatar have huge swaths of flat, dry land with minimal cloud cover or precipitation. For example, Saudi Arabia’s empty quarter desert sees sun for 80-90% of daylight hours annually and receives over 2,500 kWh/m2 of solar irradiation per year. These conditions make the Middle Eastern deserts ideal locations for large-scale solar power plants. With sparse populations and underutilized land, countries in the region have invested heavily in solar energy. The UAE currently has three of the largest operational solar parks in the world. Saudi Arabia plans to develop 70 GW of solar capacity by 2030 as part of its effort to diversify energy sources and optimize its abundant solar resources. With ample space for growth and the political commitment to expand renewables, the solar future is bright for the sun-drenched deserts of the Middle East.

Australia

Australia has emerged as a global leader in solar energy production thanks to its expansive interior deserts that receive intense sunlight throughout the year. The interior of Australia, often referred to as the “Outback”, contains some of the world’s largest deserts including the Great Victoria Desert, Gibson Desert, Great Sandy Desert, and Tanami Desert.

These deserts have minimal cloud cover, low rainfall, and high rates of solar irradiance – making them ideal locations for large-scale solar farms. Australia’s interior region receives solar radiation levels of 6-8 kWh/m2 per day, comparable to the world’s sunniest deserts. Several massive solar farms have already been constructed across the Australian Outback, including the Bungala Solar Farm (375 MW capacity) in South Australia and the Darling Downs Solar Farm (110 MW) in Queensland.

With vast stretches of unused land and intense sunlight, Australia’s interior deserts have the potential to host gigawatt-scale solar facilities. The development of major renewable energy hubs in the Outback will be crucial for Australia to continue transitioning away from fossil fuels and meet its emissions reduction targets. Solar resources in the Australian desert are so plentiful that the country could even become a major exporter of solar power to Southeast Asia through undersea transmission links.

Conclusion

In summary, the regions with the highest solar energy potential globally are areas along the equator, deserts, high altitudes, and certain countries like Chile, the southwestern United States, the Sahara Desert region, the Middle East, and Australia. The combination of high sun exposure and clear skies in these locations maximize solar irradiation. Regions along the equator receive the most direct sunlight with the sun directly overhead. Deserts have very few clouds and precipitation, allowing for abundant solar resources. High altitudes also receive more intense sunlight due to less atmosphere interference. Therefore, the most ideal conditions for harnessing solar power are found near the equator, in arid desert climates, and at high elevations. Countries fitting this profile like Chile, the American southwest, Sahara nations, Middle Eastern countries, and Australia consequently have some of the greatest solar potential on the planet. The intense sunlight available in these areas make them prime regions for solar energy generation.