Solar Dish Micro Gas Turbine Technology for Distributed Power Generation

Abstract

To enable renewable distributed power generation with minimum reliance on the grid, it is essential to develop systems that are able to operate in stand-alone mode. Advances in the development of parabolic dish systems powering a micro gas turbine coupled to thermal energy storage offer this possibility through being able to operate without the need for backup power except when there are days with lengthy periods of clouds. Further backup can be provided through hybridisation with fossil fuels which could allow the system to operate completely in stand-alone mode (dispatchable). Although such systems are still in the development stage, they potentially offer a substantial advantage over photovoltaic cells that create significant grid instability if operated without local backup. The alternative is to provide battery storage which is very expensive or to provide diesel engines’ backup which has adverse environmental impact. This chapter describes recent developments in dispatchable parabolic dish solar concentrator systems powering a micro gas turbine operated by a single dish that tracks the sun on two axes. System arrangement and component design options are discussed. A bespoke micro gas turbine design is required with the aim to minimise the overall cost of the system which is dominated by the dish. The mechanical arrangement poses significant challenges compared to conventional micro gas turbines due to the potentially wide operating range and the interconnected thermal management requirements of the micro gas turbine, high-speed alternator, recuperator and solar receiver. Solar receiver system design is of importance when the system is to be integrated with high-temperature thermal energy storage depending on the storage technology used. Safe and efficient operation requires the development of suitable operation and control strategies that will also be discussed in this chapter.