The Photovoltaic Heat Island Effect: Larger solar power plants increase local temperatures

TLDR

Photovoltaic power plants may create a heat island effect by altering albedo, vegetation, and terrain, yet prior studies have been mainly theoretical or limited to a single biome, raising uncertainty about their real‑world impact. The study seeks to empirically assess the photovoltaic heat island effect across three biomes, aiming to identify its underlying causes, magnitude, and mitigation strategies for decision‑making in semiarid regions. Researchers conducted field experiments measuring nighttime temperatures over PV installations in three distinct biomes to capture the heat island phenomenon. Results showed that PV plants were 3–4 °C warmer than surrounding wildlands at night, contradicting model predictions that PV systems should lower ambient temperatures.

Abstract

Abstract While photovoltaic (PV) renewable energy production has surged, concerns remain about whether or not PV power plants induce a “heat island” (PVHI) effect, much like the increase in ambient temperatures relative to wildlands generates an Urban Heat Island effect in cities. Transitions to PV plants alter the way that incoming energy is reflected back to the atmosphere or absorbed, stored, and reradiated because PV plants change the albedo, vegetation, and structure of the terrain. Prior work on the PVHI has been mostly theoretical or based upon simulated models. Furthermore, past empirical work has been limited in scope to a single biome. Because there are still large uncertainties surrounding the potential for a PHVI effect, we examined the PVHI empirically with experiments that spanned three biomes. We found temperatures over a PV plant were regularly 3–4 °C warmer than wildlands at night, which is in direct contrast to other studies based on models that suggested that PV systems should decrease ambient temperatures. Deducing the underlying cause and scale of the PVHI effect and identifying mitigation strategies are key in supporting decision-making regarding PV development, particularly in semiarid landscapes, which are among the most likely for large-scale PV installations.