Thrace Group has developed a reflective, transmissive film made of polypropylene resins and coated with a thin white layer that reflects ultraviolet (UV) rays. It claims the membrane increased the energy yield of a large-scale pilot installation by 4.5 percent.
The packaging solutions manufacturer claims minimal benefit in plant configurations where modules are mounted on fixed traction piles, 0.8m clearance between module rows and a 20 degree slope. It also claims a bifacial gain of up to 40%, which can vary depending on the configuration of the solar plant.
The Helios Reflect System (HRS) “combines a weed-blocking layer to suppress weeds and preserve the benefits of using bifacial modules with an albedo enhancement layer that maximizes the solar radiation received by the backside of the PV modules,” George Papagiannis, sales and marketing manager at Thrace Group’s plastics division, said pv magazine.
The top layer is made of polypropylene resins, giving it fire retardant properties, while the permeable membrane preserves the soil’s biodiversity and moisture content, allowing for full restoration of the land after removal. The material is durable, reusable and recyclable at the end of its life, with the top layer lasting more than five years and the bottom layer about 10, according to Papagiannis.
Thrace Group installed the solution on two 1 MW bifacial PV plants in Xanthi, Northern Greece, and compared measurements with a 1 MW control plant in the same area over the course of a year.
In HRS installations, the albedo reflectivity increased by 69% and the bifacial gain increased from 12% to 17%. Bifacial modules’ backside power generation increased by at least 42%, resulting in an overall energy yield increase of at least 4.5%, according to Thrace Group.
“It is even up to the stakeholders of the solar project to decide which features of the plant need to be optimized so that the AC capacity does not limit the project’s ability to maximize the benefits of albedo enhancement,” said Papagiannis.