Concentrated Solar Power (CSP) plants with highly concentrating collectors that are located in deserts usually have an abundance of sunlight to generate energy with.
Concentrated Solar Power (CSP) plants with highly concentrating collectors that are located in deserts usually have an abundance of sunlight to generate energy with. Unfortunately, the mirrors must also be cleaned regularly and water is scarce and expensive in such regions. Maintenance work in remote areas is time-consuming and not exactly inexpensive.
ZED Solar from Pakistan has now developed a parabolic dish collector specifically for harsh conditions in remote desert regions. The Solar Invectus collector is equipped with an automatic cleaning system that requires only 6 litres of water for the 53 m² mirror surface. In addition to saving water, the system eliminates the need to have personnel stationed at remote locations.
There are several application areas for the collector. One of them is to install a Stirling engine at the focal point to generate electricity. According to the company, this process of converting solar energy into electricity has an efficiency ratio of 30%. Special solar cells for highly concentrated sunlight can also be used. These are particularly suitable if there is a need for heat in addition to electricity at the installation site. The solar cells need to be cooled and the excess heat can be used to power an absorption chiller, for example, if there is a local need for air conditioning.
In addition to generating electricity, another key application is process steam. This can be used in desalination plants, for example. Drinking water is a precious commodity in the desert regions of the world.
The system can also feed steam into the steam circuit of a conventional gas power plant in order to reduce the amount of natural gas needed. The collector can deliver steam at a temperature of 565 °C for this application, which is called an Integrated Solar Steam Cycle (ISSC).
The collectors have a diameter of 9 m, a mirror surface area of 53 m² and a focal length of 5 m. One special feature is the fact that the collectors do not require heavy support structures on the rear side. This is achieved by the mirror having a very high level of rigidity.
The collectors can track the sun biaxially with a precision of 0.01 degrees. This is controlled by a PLC unit that calculates the exact position of the sun. The system also uses solar radiation sensors.