The mirrors that incorporate the heliostats, parabolic concentrators or solar device are exposed to the toughest of atmospheric conditions and, in some cases, endure extreme conditions owing to the places where they are located, chosen to make the most of the hours of sunlight. The inclemency of the weather, like rain, wind or dust cause impurities and dirt to accumulate on the mirrors and the rest of the machinery, which undermines efficiency in capturing energy and good functioning of the plant.
To solve this problem, IK4-Tekniker researchers have developed a low-cost but highly sensitive sensor that measures the loss of reflectance of the mirrors. Thanks to this device, the loss of reflectance can be calculated for each mirror with the purpose of optimising the overall maintenance of the solar plant.
Experts put the degradation of energy efficiency in dry zones or in ones close to deserts at 0.25% per day. However, the loss of efficiency is not homogeneous throughout the plant. That is why the new device designed by IK4-Tekniker will enable individualised cleaning plans to be designed for each mirror, which will help to lower the cost of the plant's maintenance process and increase profitability.
The device is fitted to a glass surface and to a hermetically sealed cover that contains an opto-electronic measuring system. This system uses an infrared emitter and measures the light projected towards the particles deposited on the glass. The performance of the device is very sensitive so even the smallest, most isolated dirt particles can be detected.
Researchers at the IK4-Tekniker R&D centre located in the Basque town of Eibar have already assembled and tested a prototype of the device at their laboratories.
A sensor developed by IK4-Tekniker offers a solution that combines high sensitivity with low cost, which means it is a very competitive solution for improving the maintenance processes of solar plants, infrastructure that is highly sensitive to atmospheric conditions.