Emerging field of ‘energy meteorology’ sheds light on solar farms’ desert impact

Rooftop solar panels are popular in many parts of the world, but power is generated much more cheaply and efficiently in utility-scale solar farms. Often, though, these large-scale solar farms are deployed in desert habitats, which contain native flora and fauna that are highly sensitive to changes in temperature and humidity.

In a study recently published in Advances in Atmospheric Sciences, Professor Carlos Coimbra of the University of California San Diego outlines in detail the thermal balances between solar farm panels and the surrounding environment, which can then be used to examine the thermal effects of solar plants on desert habitats and vice versa.

The work falls under the umbrella of the emerging field of “energy meteorology,” which in its broadest sense covers any effect that weather has on power generation, transmission and distribution systems. In Professor Coimbra’s study, while the use of energy meteorology is restricted to solar power generation, its usual scope is also expanded to include not only the effects of weather on solar power plants, but also the reverse, i.e., the effect of solar power plants on the local environment.

The ability to calculate in detail the thermal balances of solar panels, which are characterized according to their main material components, allows relationships to be derived between difficult-to-measure flow-dependent variables such as the mean convective heat transfer coefficients and radiative fluxes to and from the panels. These relationships can then be exploited through measurements or model estimates to develop a more complete and consistent picture of solar farm thermal effects on the local environment.

In addition, the study puts forward a method that can classify regional microclimates in terms of the effective optical depth of the cloudy atmosphere. Such a classification can provide resourcing information that complements the monthly, daily, or hourly averaged values of cloudiness or clearness indices for shortwave radiation used in the design, siting and management of solar power plants.

“It behooves us in the solar energy research community to answer concerns and criticisms that the solar power industry encounters with the best possible science. It could very well be that the net thermal impact of large-scale power plants is minimal, or even benign, but the conflicting results reported in the research literature point toward the need to study the problem from the standpoint of fundamental thermal balances,” explains Professor Coimbra.

In this respect, the work reported in this paper stands as an attempt to motivate solar engineers and energy meteorologists alike to push forward with studying and assessing the environmental impacts of large-scale solar farms. Essentially, the analysis is intended to serve as a research primer for those interested in exploring new research opportunities in energy meteorology applied to solar farms.