flowrates will be much smaller than for systems which deliver sensible heat or even for system 2 which delivers sensible heat and latent heat in steam. The costs of counter flow pipe heat exchangers which could simply be two concentric pipes and water separators are not included in the study, but are expected to be minimal. These five approaches to connecting the field of dish collectors to a central Rankine power plant have been evaluated. The capital costs and cost of losses are minimized for each approach and expressed as a function of the total heat transported. The temperature rise in the collector is an important factor, as is the value assumed for the solar insolation, the collector efficiency and the ground cover ratio. The analysis of the energy transport subsystem considers these various effects in an attempt to make reasonable decisions for the entire system. Section 3.2 develops this analysis, and Section 4.2 integrates these data into a complete power plant evaluation. The question is often raised of how difficult it is to maintain and operate an extensive heat transport system that has, as in system 2, a high pressure (1500 psi) and high temperature (~950°F) fluid. Current practice in the utility industry uses higher temperatures (1100°F) and pressures (3500 psi) in the piping system between the boiler and the turbine; the transit distance is typically between 100 and 200 ft. This high temperature piping network is considered a high reliability component by the utility industry. When this piping network was applied to the solar plant of this study, the steam conditions were derated somewhat, but the length of travel was increased an order of magnitude to approximately 2000 ft for a 100 MWe sun following plant. Although it is an area that requires some further study, by using current installation practice, expansion loops, drains and traps, the use of an extensive piping network to transport heat to a central site is considered a reasonable concept. The impact on cost and performance are evaluated in Section 3.2.
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