Conservation Comment: A bright future for solar power

Scientific American suggests that if we "cover around 4 per cent of all deserts with solar panels, you generate enough electricity to power the world". Photo / Getty Images

The US Department of Energy claims that in a single hour, the amount of power from the sun that strikes the Earth is more than the world consumes in a year.

Scientific American suggests that if we "cover around 4 per cent of all deserts with solar panels, you generate enough electricity to power the world". Although much has been made about the carbon costs of solar production and transportation, it is now generally accepted that the carbon payback period is an average of three years.

According to recent scientific studies, the following 25 average years of their life span would thus be "carbon negative".

In New Zealand, a large-scale solar facility probably would not be feasible or necessary with our ample wind, geothermal, hydro power and lack of deserts. Nevertheless, small scale solar is certainly achievable in boosting our electric grid (already 80 per cent renewable) closer to 100 per cent.

However, such large-scale projects would likely be essential to meet climate and economic growth needs on a global scale. All continents have desert regions that could be utilised. As an added benefit, such large-scale solar complexes would also have the extraordinary benefit of growing plants.

A 2018 study in the journal Science on large-scale wind and solar farms in the Sahara finds that large collections of solar panels appear capable of bringing rains to the desert.

They would create a feedback loop which would create "more than a twofold precipitation increase, especially in the Sahel (desert/savanna transition area), through increased surface friction and reduced albedo: solar panels reflect less sunlight than Saharan sand, thus warming the land".

The resulting increased vegetation would additionally increase precipitation through evaporation and surface friction. Nevertheless, a number of caveats on large scale solar complexes exist.

They include the political, in transferring the energy from one nation to another – which could in theory be overcome with secure contractual agreements. Knock off effects such as blocking dust from the Sahara that contributes to plankton bloom in the Atlantic and fertilising the Amazon need to be mitigated by careful planning.

More study is needed to alleviate other environmental effects such as shifting the Atlantic Niño weather patterns.

Desert dust and water scarcity also pose difficulties. Such facilities, particularly concentrated solar sites (that use lenses and mirrors to focus the light) need ample water for cooling. Dust that contributes to blocking sunlight on the panels often needs to be cleaned with water.

Deserts by definition do not have much water. However, alternatives to water use include efficient electrostatic cleaning while rotating panels downward during dust storms that would cut water use dramatically.

Locating the complex near seas and dams could also provide access to water for cooling as would hybrid cooling/cleaning applications. "Dry cooling" techniques using air flows are now commonplace and currently mandated in California for solar complexes.

After several years of foundering, ventures such as the failed European-Sahara Desertec project, desert energy is back with hope for hydrogen production and lower costs. New EU ventures between North Africa and Europe have recently been initiated to produce hydrogen from solar.

According to the Business Insider, the price of "utility-scale solar power has dropped by 86 per cent since 2009". Carbon Brief states that "the world's best solar power schemes now offer the 'cheapest … electricity in history' with the technology cheaper than coal and gas in most major countries". Solar, indeed has a bright future.

Brit Bunkley is an internationally exhibiting artist, retired from UCOL. He has taught various political science courses.