Solugas - Solar Up-scale Gas Turbine System

Abstract

In order to compete with conventional electricity generation, one of the most promising concepts for the cost reduction of solar thermal electricity is the introduction of the solar energy into the Brayton topping cycle of a combined cycle power plant: the results is the solar hybrid technology. In this way the solar heat can be converted to renewable electric energy with the highest currently available conversion efficiency of modern combined cycle plants. Main objective of Solugas is to demonstrate a full functional integrated solar-hybrid driven gas turbine system on a commercial scale, the performance and cost reduction potential and the persistence of its components, especially the solar receiver. By introducing the solar energy into a Brayton cycle which could also have a bottoming Rankine cycle, a solarised combined cycle (CC) power plant with highest conversion efficiencies can be obtained. By heating pressurized air, the solar heat can be directly fed into the gas turbine without the losses of an additional heat exchanger. A further, but not less important, advantage of solar driven gas turbine systems is the low water consumption. Solar driven gas turbines that are operated in recuperated mode do not require cooling water, and for solar-hybrid Combined Cycles the water requirement can be reduced in comparison to a solar steam power plant. This reason is crucial as solar thermal power plants are better located in arid and desert areas, which benefit from both, strong direct solar irradiation and the availability of large areas of land but suffer from a scarcity of water. Solugas project covered a wide range of topics related to CSP including solar receiver, heliostats, turbine, high temperature interconnection and insulation systems. All components were case of study during the development of the project together with the plant characterisation and efficiency measurement. As definition of the concept, solar-hybrid systems combine solar energy and fossil fuel. Thus it provides reliable power with full dispatchability and, if bio-fuels are used, also 100% sustainable at zero net emissions. The advantages of modern gas turbines, as fast start up, low parasitic losses or compact design are kept. Systems based on gas turbines are suited for cogeneration or Combined Cycles, making them very efficient and cost effective. All objectives proposed were achieved. Following results are presented and the work carried out is explained.