Solar District-Heating System Using Seasonal Storage for the Charlestown, Boston Navy Yard Redevelopment Project

摘要

A preliminary analysis is presented for a seasonal storage solar heating system for the Charlestown Navy Yard in Boston, Massachusetts. The area occupies a prominent location in the Boston Harbor and is being receveloped for residential and commercial use. The system makes use of two large, buried concrete storage tanks totalling 5700 m exp 3 as a water heat store. Other storage facilities, including a dry dock, offer additional solar opportunities for the navy Yard as the redevelopment progresses. The analysis makes extensive use of MINSUN, a computer performance and economic simulation routine written specifically for solar seasonal storage systems. The system performance and economics are analyzed for different collector types and areas, component costs, exogenous economic conditions, and optional inclusion of a heat pump. System cost-effectiveness is defined in relation to an economic break-even situation with respect to a conventional system, and is presented in terms of a solar premium, which is the incremental cost for the solar system per MWH of conventional fuel displaced. Results indicate a solar premium of about $15/MWH for parabolic collectors and $10/MWH for advanced CPC evacuated tubes given estimated 1985 collector costs. Cost-effective solutions are found for these two and for flat plate collectors assuming projected collector costs for year 2000. Optimally sized systems for this case exhibit a solar fraction around 0.50 for the 2200 MWH annual heat load; at this point the system is volume constrained. The sensitivity of these results with respect to system parameters and economic assumptions is presented. The additional analysis and design considerations necessary before an implementation phase are outlined. System implementation is discussed in terms of the roles of the various parties involved and funding/financing possibilities. (ERA citation 08:014414)