- Parabolic troughs systems
Parabolic trough system use a bended trough which reflects the direct solar radiation onto a pipe containing a fluid which is called a receiver, absorber or collector running the length of the trough above the reflectors. The trough is parabolic in one direction and straight in the other direction. For change of position of the sun perpendicular to the receiver the trough tilts so that the direct radiation remains focused on the receiver. One advantage of parabolic trough systems is their potential for storing solar thermal energy to use during non-solar periods and to dispatch when it's needed most.
- Paraboloid or dish systems
The advantage of a dish system is that it can achieve much higher temperatures due to the higher concentration of light. Higher temperatures lead to better conversion to electricity and the dish system is very efficient on this point. However, there are also some disadvantages. Heat to electricity conversion requires moving parts and those results in maintenance. In general, a centralized approach for this conversion is better than the decentralized concept in the dish design. Second the heavy engine is part of the moving structure which requires a rigid frame and strong tracking system. Furthermore, parabolic mirrors are used instead of flat mirrors and tracking must be dual-axis.
- Power tower systems
The advantage of this design above the parabolic trough design is the higher temperature as well. Thermal energy at higher temperatures can be converted to electricity more efficiently and can be more cheaply stored for later use. in addition, there is less need to flatten the ground area. In principle a power tower can be built on a hillside. Mirrors can be flat and plumbing is concentrated in the tower. The disadvantage is that each mirror must have its own dual-axis control while in the parabolic trough design one axis can be shared for a large array of mirrors.
- Solar chimneys
Solar chimney often referred to as a thermal chimney. It is a new method of improving the natural ventilation of buildings by using convection of air heated by passive solar energy. A simple description of a solar chimney is that of a vertical shaft utilizing solar energy to enhance the natural stack ventilation through a building. The solar chimney can work better by adding a tremble wall. The advantage of this design is that the system may be reversed during the cold season, providing solar heating instead. Another advantage is the collector can use all solar radiation, both direct and diffused. Also Due to the heat storage system the solar chimney will operate 24h on pure solar energy. Consider that the building materials needed for solar chimneys, mainly concrete and glass and they are available everywhere.