New model! Every PV plant needs

Researchers from Portland State University, the University of Utah and the National Renewable Energy Laboratory (NREL) say they have discovered a new way to improve the efficiency of solar projects by enhancing natural cooling, which is achieved by using the existing geometry of the plant.

The researchers found that solar power plants with optimally spaced components in the right direction can cool themselves using the surrounding wind through convection. The study found that increasing the height of the solar cells as well as increasing the module row spacing can increase the output power by 2-3%.

Contrary to common belief, too much sunlight or heat can reduce the efficiency of photovoltaic power generation. Photovoltaics work more efficiently when operating at lower temperatures.

This correlation between geometry and efficiency is a big step towards predicting convective cooling based on the unique arrangement inherent in solar power plants," said Sarah Smith of Portland State University, author of the article ...... This paves the way for the industry to come up with more accurate models for predicting energy production and costs."

The team found that solar cell efficiency decreases by approximately 0.5% when the operating temperature rises by 1°C. As an example. Energy losses would account for 12% in a typical PV plant, where the operating temperature of the modules is nearly 25°C higher than the ambient temperature.

Modern cooling methods force wind or water to interact with the surface of the solar modules, while other methods use specific materials that are less thermally sensitive, but these techniques require significant resources to operate.

This calls for effective and trouble-free cooling measures for solar power plants.

Each plant requires a different cooling model

The team has improved the model for calculating how much energy a particular solar system will generate based on factors such as material, environmental conditions and module temperature.

This is achieved by paying particular attention to the geometry of the solar plant, or how much space is available between the components.

The team's assumption is that the most accurate estimate of the convection and production efficiency of a solar system must take into account the plant as a whole and all possible variations in configuration.

Smith said, "This means that the heat removal airflow will also move differently depending on the arrangement of each solar plant, ultimately changing the efficiency of heat removal from the surface of the modules."

To confirm their model, the researchers conducted wind tunnel experiments and high-resolution simulations, and collected real-world environmental data.

This was followed by an investigation into the relationship between PV heating and cooling and changes in module height, row spacing, angle and wind force.

Earlier, NREL had revealed that spacing out rows of solar modules could help maintain module temperatures, which typically rise when solar modules are exposed to direct sunlight for long periods of time, leading to a reduction in module efficiency.

In November 2022, a team of researchers from the University of Alcala in Spain claimed that reducing the temperature of solar modules by 20ºC could lead to a net system efficiency improvement of around 14%.