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.
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.
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.
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.
“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.
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.
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.
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.
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.
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.
“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.”
The research was presented in “Persistent site-scale warming associated with solar photovoltaic installations,” published in the Journal of Environmental Management.“These findings underscore the need to consider potential environmental trade-offs in future PV deployment strategies,” the scientists concluded.
Researchers from China’s Inner Mongolia University of Finance and Economics, Peking University, Inner Mongolia Institute of Water Resources Research, and Inner Mongolia Agricultural University.
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