New algorithm reduces solar module temperature during clipping, curtailment

UNSW researchers have developed a thermal-aware tracking algorithm that reduces solar module temperatures and UV exposure during inverter clipping and curtailment, slowing degradation without lowering AC output. Tested in Chile’s Atacama Desert, the strategy was found to lower module temperatures by up to 7.7 C.

February 17, 2026 Emiliano Bellini

Image: UNSW

A research team from the University of New South Wales (UNSW) has developed a thermal-aware tracking algorithm to lower solar module temperatures during periods of clipping and curtailment.

Inverter clipping occurs when a PV system’s DC energy is larger than the maximum input size of the inverter. This saturates the inverter and the excess DC energy is not converted into AC. Curtailment refers to the intentional reduction of potential electricity generation below what a power plant could have produced, typically to maintain grid stability when supply exceeds demand or when network constraints arise.

“The algorithm moderates plane-of-array irradiance only during clipping periods, when additional irradiance cannot be exported,” the research’s corresponding author, Bram Hoex, told pv magazine. “It also reducex cumulative UV exposure, further mitigating long-term degradation drivers.”

“The proposed strategy explicitly aligns tracker control with real grid constraints, improving durability without compromising AC output,” Hoex went on to say. “The concept can be extended beyond clipping to grid curtailment scenarios, which are increasingly common.”

In the study “Thermal-Aware Tracking for Photovoltaics: Reducing Module Degradation Without Sacrificing Yield,” published in IEEE Journal of Photovoltaics, the researchers explained that the algorithm is effective across different sites, but its benefits and optimal use depend on local climate and site conditions. Factors such as wind, humidity, cloud cover, altitude, terrain, shading, temperature, and irradiance influence convective and radiative cooling, guiding optimal panel tilt.

The algorithm first simulates DC and AC power output and module temperature across different tilt angles, identifying the tilt that delivers full inverter AC power at the lowest module temperature. Clipping is predicted by comparing simulated DC power with the inverter limit, and if clipping is expected, the algorithm checks whether the event exceeds a set duration.

Short clipping events are ignored, as rapid tracker movements are impractical. For longer events, the algorithm selects tilt angles that maintain inverter-limited AC output. At each timestep, it chooses the tilt minimising module temperature while respecting the actuator speed limit. Any tilt positions that require movement beyond the actuator’s capabilities are excluded. If a clipping period is too short or all feasible angles violate the speed limit, the tracker defaults to standard tracking.

Testing took place at the Plataforma Solar del Desierto de Atacama in northern Chile. The site featured four single-axis trackers, each with four active module strings of different technologies plus dummy modules. Each tracker connected to a 60 kW inverter with separate MPPT inputs monitoring DC output, module temperatures, and plane-of-array irradiance. A weather station recorded ambient conditions, with all data logged every minute.

The team evaluated two tilting strategies during clipping. The lead-only approach kept the tracker slightly ahead of the standard angle to limit movement, while the lead-lag strategy allowed the tracker to move ahead in the morning and lag in the afternoon, modifying the panel’s thermal exposure.

Results showed the algorithm could reduce module temperature by up to 7.7 C, with average reductions of 2.7–3.1 C depending on the strategy. The lead-lag approach enhanced radiative cooling, offering stronger thermal benefits than the lead-only method.

Arrhenius analysis indicated that these temperature reductions could significantly slow degradation rates, which approximately double for every 10 C increase. The algorithm also reduced daily global UV irradiance by up to 47 Wh/m², mitigating UV-induced degradation and thermal stress.

“This work bridges system-level control and materials reliability, showing that smart operational strategies can directly mitigate thermally driven degradation in utility-scale PV,” Hoex said. “In future work, we will integrate these findings and explore module degradation at a global scale to put our lab results into perspective.”

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