Shiraz power plant is a parabolic trough solar thermal power plant which uses parabolic trough collectors in order to produce electricity from sunlight. The parabolic trough collectors are structures with long rows of curved glass mirrors focusing the suns energy on an absorber pipe located along its focal line. These collectors arranged rows in the collector field. These collectors track the sun by rotating around a north-south axis. The heat transfer fluid (HTF), a synthetic oil, is circulated trough the pipes. Under normal operation the heated HTF leaves the collector with a specified collector outlet temperature and is pumped to a central power plant area. In the next stage, the HTF is passed through three heat exchangers where its energy is transferred to the power plants working fluid, which is water. The heated steam is used to drive a turbine generator to produce electricity. The solar thermal power plant specifications are presented in the Table 2.

This power plant implemented as a solar test facility site for assessing domestic potential of Iran in manufacturing and commissioning large scale parabolic trough solar power plants. On the other hand, long term operation of solar thermal power plants would be evaluated by this pilot solar thermal power plant.

Different facility of this power plant was designed and constructed by domestic manufacturer. These parts includes: Curved Mirrors, Parabolic Trough Structure, Instruments and Control devices and also Heat Transfer Fluid. One of the most important parts of parabolic trough power plants is absorber tube which was imported from Germany.

After the installation process, the first stage was testing the first loop. In this stage, the HTF was circulated in one loop and the oil increase water temperature in the prototype heat exchanger which was designed just for assessing operation of one loop. The operation of whole power plant was confirmed by testing the first loop operation. Figure 3 illustrates the steam generated by one loop in less than 30 minute. The HTF temperature received to 255 °C by a single loop in open loop operation. The operation was open loop because the HTF temperature decreases constantly by warming water, generating steam and injecting into air. When water decreases the water pump start to work and compensate the water shortage[3].

The next stage is total commissioning of parabolic trough power plant. The information of long term operation of the power plant will be used for future decision making. There is a comprehensive evaluation will be done on the collector field operation and maintenance and also power plant equipments life time. The other important parameter which could be assessed is the overall efficiency of the collector field[3].

There were different challenges for installing the first pilot power plant. The main challenge was that decision makers could not be easily convinced of the reliability of future solar power plant. Another critical challenge was the domestic potential for manufacturing solar systems and at last, Iranian experts lack of knowledge about solar systems.

Commissioning of this power plant and testing one loop for generating steam increased the decision maker’s tendency towards solar thermal power plants, and this will help deployment of CSP technologies in next step. However, by installing this project many different weaknesses of domestic manufacturer unclosed. In this respect, empowering domestic manufacturer potential by using foreign experts is vital.

The other significant challenge was the capital cost of this solar power plant which was implemented in small scale. The capital cost of this power plant is very high and it is expected that this price will decrease and approach the International solar thermal capital cost. This price is about 12000 $/kW which is not comparable with large scale solar power plants. It is expected that the solar power plant would be feasible in Iran with 30MW capacity or more.