Solar energy systems can get a boost from leaf-like concentrators

In another breakthrough in solar energy, scientists have perfected luminescent solar concentrators (LSCs), a technology that dates back to the 1970s, when photovoltaic cells were first developed.

Scientists from Ritsumeikan University in Japan have developed a “leaf LSC” model that promises to overcome the limitations of LSCs by improving the collection and transmission of light to photovoltaic cells.

Traditional LSC systems are difficult to scale to larger applications because they rely on mirrors and lenses.

Luminous solar concentrators can capture scattered light and are used in photovoltaic solutions where their translucent and colorful properties provide aesthetic value.

Improving photon collection efficiency

However, the new design of the maple leaf model increases photon collection efficiency, reduces losses, and makes the system more versatile and replaceable, which may contribute to a more practical and widespread use of solar concentrators.

The main challenge of scalability led experts to design a leaf LSC by using smaller, interconnected luminescent components that function similarly to leaves on a tree.

The study noted that this innovative design involves placing luminescent plates around a central luminescent fiber so that the plates face the fiber.

“This arrangement allows the incident photons to be converted into PL photons by the plates, which then travel through the fiber and are collected at its end by the photovoltaic cell.”

Transparent optical fibers connected multiple fibers to a single photovoltaic cell, increasing efficiency by increasing the light-collecting surface area and minimizing photon losses due to self-absorption and scattering.

Reducing module size to increase solar concentrator efficiency

As a result of using a new modular solar concentrator design, scientists observed an improvement in photon collection efficiency due to the smaller size of the individual modules.

The size of the LSC square sheet has been reduced from 50 mm to 10 mm, which significantly increases efficiency.

The modular design also allows for easy replacement of damaged components and easy integration of new luminescent materials as they are developed.

The researchers noted in the statement that the experiments showed that the optical efficiency of these leaf-like structures can be calculated analytically.

This was based on the spectrum and intensity of the incident light, using a single point excitation technique.

Sean Shaheen, editor-in-chief of JPE, professor of engineering and physics at the University of Colorado at Boulder, and member of the Institute for Renewable and Sustainable Energy, said:

“These findings represent a creative approach that advances the concept of luminescent solar concentrators that efficiently direct sunlight toward adjacent photovoltaic devices.”

Shaheen added that by combining scalable, bio-inspired designs with improvements in optical engineering, the authors have increased the performance of their devices and reached the level necessary for practical use.

Flexible, scalable solar energy

Leaf’s new approach paves the way for more flexible and scalable solar energy solutions.

Seeking to revolutionize the use of solar concentrators, scientists have addressed the concept of energy harvesting and made new solar energy systems more efficient and flexible.

This technology enables the construction of large-scale integrated photovoltaic systems.

Experts believe that with technological developments, Leaf LSC has the potential to significantly increase the efficiency of solar energy systems and contribute to more sustainable energy solutions.

The study was published last month (July 19, 2024) in the journal Photonics for Energy Magazine.