Three-layer microtracking concentrating solar panels significantly increase the efficiency of energy production

Testing the prototype. Small dark squares on the increase - photocells.

The next step in increasing the efficiency of solar cells was a joint team of engineers from the universities of Pennsylvania and Illinois. Their product belongs to the class of concentrating photovoltaics , i.e. uses lenses to concentrate sunlight on small photocells.

Existing analogues using lenses already exist - for example, similar photocells are used on the ISS. However, they are expensive to produce, and require a sophisticated guidance system for tracking the sun, because the focused beam of light moves with the sun. To get meaningful returns, such panels should be about the size of a roadside billboard. As a result, they can not be placed on the roof of your house.


Industrial Concentrating Panels
')
A team of engineers seeks to reduce the cost and simplify production. The lenses are made of plastic (for a test sample, they were printed on a 3D printer). Miniature (1 mm ^{2 in} total) photocells are made of gallium arsenide. To adjust the focus due to the movement of the Sun, engineers made the structure of the panels three-layer.

The top layer contains lenses, the bottom one - concave mirrors, which help to focus the light, the intensity of which as a result increases about 200 times. And between them is a layer of glass or plastic containing photocells, which moves in the same plane with the help of motors.

This layer is in the optical oil, which reduces friction, which reduces the energy costs of the motors. This design is able to effectively focus the light on the photocell during the entire 8-hour daylight hours, while the middle layer only has to be shifted within one centimeter. The total thickness of the panel is 1 cm, and for 99% it consists of plexiglass, which in the future makes its production inexpensive.



Noel Chris Gibink , an assistant professor, says : “We strive to ensure that such a microtracking panel can be placed on the roof of a house in the same way as a classical one, and at the same time receive a much larger output from it. The simplicity of our solution definitely has practical significance. ”



Of course, for effective operation of the panel, it requires exposure to direct sunlight. In cloudy weather, she will not be able to concentrate the light and will lose the advantage in efficiency.