Solar concentrators

Abstract

In spite of several successful alternative energy production installations in recent years, it is difficult to point to more than one or two examples of a modern industrial nation obtaining the bulk of its energy from sources other than oil, coal, and natural gas. Thus a meaningful energy transition from conventional to renewable sources of energy is yet to be realized. It is also reasonable to assume that a full replacement of the energy currently derived from fossil fuels with energy from alternative sources is probably impossible over the short term. For example, the prospects for large-scale production of cost-effective renewable electricity remains to be generated utilizing either the wind energy or certain forms of solar energy. These renewable energies face important limitations due to intermittency, remoteness of good resource regions, and scale potential. One of the promising approaches to overcome most of the limitations is to implement many recent advances in solar thermal electricity technology. In this section, various advanced solar thermal technologies are reviewed with an emphasis on new technologies and new approaches for rapid market implementation. The first topic is the conventional parabolic trough collector, which is the most established technology and is under continuing development with the main focus being on the installed cost reductions with modern materials, along with heat storage. This is followed by the recently developed linear Fresnel reflector technologies. In two-axis tracking technologies, the advances in dish-Stirling systems are presented. More recently, the solar thermal electricity applications in two-axis tracking using tower technology is gaining ground, especially with multitower solar array technology. A novel solar chimney technology is also discussed for large-scale power generation. Non-tracking concentrating solar technologies, when used in a cogeneration system, offer low cost electricity, albeit at lower efficiencies - an approach that seems to be most suitable in rural communities.