Application Engineering Data for Solar Energy Utilisation: Solar Tables for Water Heating at Pondicherry

摘要

In spite of large-scale applications of solar energy in India during the last 25 years, there is hardly any application engineering data available. Instead, there are rules of thumb, spoken or latent (501/m~2 day for water heating for all collectors at all places for a fixed tilt), or sophisticated computing programs like TRNSYS, which are used by consultants only for larger projects. Collector test curves (BIS standards) are used for mean monthly conditions and radiation statistics are rarely taken into account. This article fills this gap with a case study for solar water heating at Pondicherry. The method is general and can be used anywhere for any application. A figure of merit is calculated as MJ/yr m~2 per Rupee of capital cost of installation to help select the system for maximum useful heat collected per unit variable costs. The essence of the method is a single design equation, which converts BIS test data design curve for generating application data with a design accuracy of 10%. Minimal computational effort in the form of a Microsoft~® (MS) Office Excel program is involved and tables can be generated for a single application in less than few minutes with data input requiring less than an hour.