Comparison of simple methods for the design of central solar heating plants with seasonal storage

The development of central solar heating plants with seasonal storage (CSHPSS) to cover part of the heating demand of buildings with district heating in the residential sector is becoming an economically viable option that can contribute significantly to the reduction of the consumption of fossil fuels. The calculation of CSHPSS systems, with a highly dynamic behaviour, is a complex process in which climatic, demand and design data are required. Simple calculation methods can be used to perform feasibility and pre-design studies enabling an estimation of the annual result. A review of several simple methods that have been proposed for the evaluation and design of the main components of CSHPSS is presented. The methods share some characteristics: main equipments considered, dependence with solar radiation and heating demand; and differ in other aspects: design parameters of the main equipments, secondary equipment considered, degree of detail of climatic and demand input data and equations of the model used to calculate the performance of the system. In this paper a description of each method is presented and results obtained for a base case (installation that produce 50% of the space heating demand for a community of 1000 dwellings in Zaragoza, Spain) are compared. (C) 2014 The Authors. Published by Elsevier Ltd.