Concentrating solar power (CSP) plants use mirrors to concentrate the sun's energy to drive traditional steam turbines or engines that create electricity. The thermal energy concentrated in a CSP plant can be stored and used to produce electricity when it is needed, day or night. Some methodological examples are given in the below: Parabolic Trough: Parabolic trough systems use curved mirrors to focus the sun’s energy onto a receiver tube that runs down the center of a trough. In the receiver tube, a high-temperature heat transfer fluid (such as a synthetic oil) absorbs the sun’s energy, reaching temperatures of 750°F or higher, and passes through a heat exchanger to heat water and produce steam. Compact Linear Fresnel Reflector: CLFR uses the principles of curved-mirror trough systems, but with long parallel rows of lower-cost flat mirrors. These modular reflectors focus the sun's energy onto elevated receivers, which consist of a system of tubes through which water flows. Power Tower: Power tower systems use a central receiver system, which allows for higher operating temperatures and thus greater efficiencies. Computer-controlled mirrors (called heliostats) track the sun along two axes and focus solar energy on a receiver at the top of a high tower. Dish-Engine: Mirrors are distributed over a parabolic dish surface to concentrate sunlight on a receiver fixed at the focal point. In contrast to other CSP technologies that employ steam to create electricity via a turbine, a dish-engine system uses a working fluid such as hydrogen that is heated up to 1,200° F in the receiver to drive an engine. Each dish rotates along two axes to track the sun. CSP technology can be combined with a natural gas-fired power plant (NGCC)into an Integrated solar combined cycle (ISCC) system. The CSP energy is used to either produce additional steam that is integrated in the NGCC’s steam turbine to generate electricity, or to heat the compressed air in the gas turbine before entering the combustion chamber. ISCC plants effectively help integrating solar power into the grid by circumventing the non-dispatchability of the CSP and providing reductions of operating and capital costs, and the possibility of increased operational flexibility when compared to a standalone NGCC.