Two-year testing shows how PV plants increase local temperatures in semi-arid regions

<p class="p1"><span class="s1">A two-year field study in a 100 MW photovoltaic plant in semi-arid Inner Mongolia combined ground-based sensors, radiation measurements, and UAV thermal imaging to quantify how large-scale PV installations alter local air temperature, surface temperature, and energy balance compared with nearby non-PV areas. Results show consistent site-scale warming of 0.8 C.</span></p><p>A research team from China conducted a two-year field study to assess how large-scale photovoltaic (PV) farms influence local climate conditions, with a focus on air temperature, surface temperature, and surface radiation balance. The observation campaign took place from 2022 to 2024 at a 100 MW solar PV facility located in a semi-arid desert region of Inner Mongolia.</p>
<p>The researchers combined in situ meteorological measurements, surface radiation observations, and uncrewed aerial vehicle (UAV)-based thermal infrared imaging to quantify changes in air temperature, land surface temperature, and the surface energy balance. By comparing conditions within the PV installation and in nearby non-PV reference areas, they assessed how PV infrastructure alters radiative fluxes and heat exchange processes in dryland environments.</p>
<p>The dataset provided high-resolution evidence of how utility-scale PV deployment can modify local thermal regimes and energy partitioning in arid and semi-arid landscapes, offering insight into the broader environmental impacts of rapid solar energy expansion.</p>
<p>“Our study aims to quantify the seasonal and diurnal impacts of PV deployment on near-surface air temperature; to characterize the fine-scale spatial heterogeneity of land surface temperature (LST) within and around PV arrays using UAV-based thermal imaging; and to diagnose the radiative and thermodynamic mechanisms underlying PV-induced warming by combining ground-based and aerial observations,” explained the researchers.</p>
<p>During the study period, a network of temperature sensors was deployed both within the PV plant and at a nearby reference site located approximately 10 km away to capture background conditions unaffected by solar infrastructure. These instruments were installed at a standard height of 2 m above ground level and recorded air temperature at 15-minute intervals, enabling high-temporal-resolution comparisons between the PV and non-PV environments.</p>
<p>In addition to the long-term temperature monitoring, targeted radiation measurements were conducted during an intensive field campaign in July 2023. This campaign used instrumented observation towers positioned inside the PV field and at a reference location about 2 km away, allowing the researchers to directly compare radiative fluxes under similar meteorological conditions.</p>
<p>To complement the point-based measurements, land surface temperature patterns were further examined using UAV-based thermal infrared imaging on July 29, 2023. This approach provided high-resolution spatial mapping of surface thermal conditions across both the PV installation and adjacent non-PV areas, capturing fine-scale heterogeneity that ground sensors alone could not resolve, according to the research group.</p>
<p>The results showed a statistically robust warming signal associated with the PV installation. Over the two-year observation period, the PV farm exhibited a mean air temperature increase of 0.8 C relative to the reference site, with warming observed consistently across all seasons. The study further found an asymmetry in diurnal temperature changes: increases in daily minimum air temperatures were greater than those in daily maximum temperatures, leading to a 1.9 C reduction in the daily temperature range compared with non-PV areas.</p>
<p>Consistent with these findings, UAV-based thermal mapping revealed elevated land surface temperatures within the PV field, ranging from 0.3 C to 4.1 C above adjacent non-PV regions. The radiation measurements also indicated a positive perturbation in surface energy balance, with mean daily net radiation increasing by 8.3 W m² in the PV area. This enhancement was particularly pronounced during daytime hours, when net radiation rose by up to 18.5 W m², highlighting the role of PV infrastructure in modifying local radiative and thermal dynamics.</p>
<p>“This increase in net radiation was primarily due to a decrease in albedo, which resulted in 24.6 W m2 more net shortwave radiation,” the team said. “The PV farm increased the outgoing longwave radiation by 6.1 W m2 during the daytime and 4.6 W m2 at night, which was considerably lower than the increased net shortwave radiation.”</p>
<p>The research was presented in “<a href="https://www.sciencedirect.com/science/article/abs/pii/S0301479726008297" rel="noopener" target="_blank">Persistent site-scale warming associated with solar photovoltaic installations</a>,” published in <em>the Journal of Environmental Management.</em>&#8220;These findings underscore the need to consider potential environmental trade-offs in future PV deployment strategies,&#8221; the scientists concluded.</p>
<p>Researchers from China’s Inner Mongolia University of Finance and Economics, <a href="https://www.pv-magazine.com/2026/02/18/global-warming-induced-degradation-could-raise-rooftop-solar-lcoe-by-up-to-20/" rel="noopener" target="_blank">Peking University, </a>Inner Mongolia Institute of Water Resources Research, and Inner Mongolia Agricultural University.</p>