New 36% efficient micro-CPV breakthrough from Germany boosts solar power, slashes costs

Researchers at the Fraunhofer Institute for Solar Energy Systems (Fraunhofer ISE) have achieved a significant breakthrough in solar technology, developing a micro-concentrator photovoltaic (micro-CPV) module that boasts 36% efficiency using low-cost components. 

“Micro-concentrating photovoltaic (micro-CPV) technology has the potential to contribute to the energy transition, facilitating the shift toward more sustainable and renewable energy sources by combining minimal carbon footprint and energy demand with low levelized cost of electricity,” said the researchers in a new study.

The new micro-CPV system represents an evolution of conventional concentrator photovoltaics. It utilizes miniaturized multi-junction solar cells, less than 1mm² in size, and compact optical components. 

This reduction in size not only maintains high efficiency but also offers substantial cost and performance benefits. It also allows for the integration of well-established printed circuit board (PCB) and microelectronics device fabrication processes, streamlining manufacturing.

Design cuts semiconductor requirement

Developed over four years in collaboration with industrial and academic partners, Fraunhofer’s micro-CPV technology is based on a low-cost lens array, a spherical secondary optic lens, and high-efficiency III-V concentrator solar cells supplied by Azur Space Solar Power. 

This design dramatically cuts the required semiconductor materials by a factor of 1,300 and reduces module areas by 30% compared to current state-of-the-art CPV systems. 

The modules are designed for deployment on 2-axis tilt and roll trackers to maximize sun exposure.

The performance of a demonstrator module, featuring 60 cell-lens units and an aperture area of 205.35 cm², was rigorously tested for a year at Fraunhofer ISE’s CPV test site in Freiburg, Germany, with the study concluding in February 2024.

Impressive performance

The research, recently published in IEEE Explore under the title “Power rating of a novel micro-CPV module concept and operational influences,” revealed monthly median efficiencies between 31.4% and 33.6% under real-world conditions.

“The module demonstrates an efficiency of 36.0% at CSTC and 33.0% at CSOC with operating cell temperatures around 75 °C,” noted the study. 

The researchers highlighted the module’s “overall stable performance” and “no signs of degradation,” deeming the “very high efficiencies” particularly noteworthy given the use of commercially available, low-cost components and high-throughput manufacturing processes.

Efforts for commercialization

Looking ahead, Fraunhofer ISE is actively working to bring this technology to market. 

“We are currently preparing a startup, Clearsun Energy, to commercialize the Micro-CPV technology both for Agri-PV and PV power plants in arid regions of the word,” Frank Dimroth, head of photovoltaics and concentrator technology at Fraunhofer ISE, told pv magazine. He also revealed plans for a product with an even higher 37% module efficiency.

In a related development, the research team also developed a new statistical model to assess the impact of slight deviations in component size and arrangement that typically occur in manufacturing, calling it a “crucial tool for identifying and assessing critical tolerances.”

The technology is rapidly maturing, with Fraunhofer ISE now successfully scaling up to 60 cm x 45 cm modules.