Start-up promises cheaper solar panels

03 Aug 2006

Can light-channelling technology cut the cost of solar panels and bring solar energy to the masses?

Maxxun, a spin-off company from the Eindhoven University of Technology (TUE) in the Netherlands, has developed a photovoltaic (PV) system that it claims will revolutionize solar power and bring it to households worldwide.

"Our technology reduces the required area of the PV cell. Using our panels, less than 5% of the surface area need consist of PV cell," Marcel Artz, business director of Maxxun, told optics.org. "By achieving 6-8% efficiency on full-scale products and extrapolating from our lab-scale results, we expect to be able to lower the solar electricity price from the current €0.30-0.35/kWh to €0.25/kWh."

The Maxxun solar energy system is based on combining its patented Luminescent Solar Concentrating (LSC) technology with a small solar cell. Sunlight is channelled from a large surface-area, low-cost, predominantly plastic plate to a small, efficient solar cell that converts the light into electricity.

"This is preferable and cheaper to having a large solar cell for both collection and conversion," said Artz. "The technology could have applications in areas ranging from large energy parks to households."

The system itself consists of a dye-impregnated plastic waveguide, mirrors on three sides and bottom, and a wavelength-selective mirror on the surface. Sunlight shining on the LSC system passes through the selective mirror and is then absorbed in the waveguide by dye molecules, which re-emit the light at longer wavelengths resulting in material's reddish appearance.

A fraction of the light is emitted by the dye molecules at such an angle that it is trapped by total internal reflection in the waveguide until it reaches the solar cell and is converted into electricity.

According to Maxxun, the unique feature of the system is the patented wavelength-selective mirror. In previous systems, most of the re-emitted light escaped the surface of the LSC. The Maxxun wavelength-selective mirror, says the firm, is a unique composition of chemical elements and a key innovation in LSC technology.

Last month, Maxxun was awarded first prize at the 2006 Altran Foundation for Innovation Awards out of 80 competing international projects. The team is working on a lab-scale (5x5cm); however, they have plans to scale-up. "In a year from now, we want to have full-scale, reproducible, on-spec prototypes for our product," said Artz.