In order to compensate for the lower turbine efficiency caused by the air cooled condenser at the cold end of the turbine, a gas fired boost burner has been integrated to boost the inlet steam temperature from 380C to 540C. This boost burner will contribute approx. 18% of the total heat input to the plant. Gas burnt in the boost burner is converted into electricity at a very high efficiency.

In order to compensate for fluctuations caused by cloudy weather conditions, a gas fired heater has been introduced which heats the HTF (Heat Transfer Fluid) in parallel to the solar field. This heater will only be used on cloudy days when cloud passages would cause high fluctuations at the steam generator. The heater can also be used to run the power plant even without any sun shine. This was one requirement of ADWEC (Abu Dhabi Water and Electricity Company), the off-taker of the electricity generated by Shams 1. The availability at all times of the year (the so called “firm capacity”) makes the plant more valuable for the off- taker, because he does not need to keep a stand by plant ready at his own cost for the case that he would need the power during a time when the sun is not shining. It is expected that the HTF heater will contribute approx. 4 % of the total annual energy input to the plant.