Assessment of the potential of solar thermal small power systems in small utilities. Final report

This study involved an assessment of the potential economic benefit of small solar thermal electric power systems to small municipal and rural electric utilities. Five different solar thermal small power system configurations were considered in the study representing three different solar thermal technologies. The configurations included: (1) 1-MW, 2-MW, and 10-MW parabolic dish concentrators with a 15-kW heat engine mounted at the focal point of each dish. These systems utilized advanced battery energy storage. (2) A 10-MW system with variable slat concentrators and central steam Rankine energy conversion. This system utilized sensible thermal energy storage. (3) A 50-MW central receiver system consisting of a field of heliostats concentrating energy on a tower-mounted receiver and a central steam Rankine conversion system. This system also utilized sensible thermal storage. The approach used in determining the potential for solar thermal small power systems in the small utility market involved a comparison of the economics of power supply expansion plans for seven hypothetical small utilities through the year 2000 both with and without the solar thermal small power systems. Insolation typical of the Southwestern US was assumed. A comparison of the break-even capital costs with the range of plant costs estimated in this studymore » yields the following conclusions: (1) The parabolic dish concentrator systems could be economically competitive with conventional generation if the lowest capital costs can be achieved. (2) The variable slat concentrator and central receiver systems would have to achieve lower costs than the lowest in the cost ranges generally assumed in the study to become economically competitive. (3) All of the solar thermal plant types are potentially more competitive in utilities which are heavily dependent upon oil.« less