Using PLEXIGLAS® SOLAR IM20 for building a sunlight modulation roof, scientists from the national Chiao Tung and Ming-dao University in Taiwan collaborated with Evonik to optimize solar energy utilization on both illumination and photovoltaic power generation.

As the sun provides seemingly unlimited amounts of light, scientists and engineers all over the world research about utilizing this excess energy in various ways. Solar Panels for example are already established as a completely renewable energy in many countries.

The major function of solar energy for the living of human beings, animals and plants is illumination. The world’s population is growing fast and challenges the brightest minds everywhere to come up with innovative ideas concerning sustainability, quality of life and protecting the environment. While global food needs increase, greenhouses provide a continuous way to grow plants independently from the season.

The idea of this project is to equip a greenhouse with solar panels and generate electric energy while at the same time provide plants with all the necessities to grow fast and healthy. Plants need sunlight for their metabolism and ultimately growth. Artificial illumination seems like the logical next step but since all energy transformation includes some efficiency loss it should be avoided if possible.

Instead the team has come up with a novel design where the special architecture of the sunlight modulation roof let’s through 20% of the solar energy for illumination while 80% are used for photovoltaic power generation. Extrusion in the production process turns the transparent PLEXIGLAS® roof into a Fresnel lens structure that focuses the light onto the reflector mounted underneath. From there the light travels to the photovoltaic solar panel. Angle and size of the reflector are customized to meet regional and seasonal demands.

In Changhua, on the west coast of Taiwan, construction of a greenhouse to test the structure and compare it to traditionally mounted solar panels is almost finished and data collection has started in mid-September.