TEXAS RENEWABLE ENERGY EVALUATION SOFTWARE (TREES): A SCREENING TOOL FOR ECONOMIC ASSESSMENT OF RENEWABLE ENERGY OPTIONS

摘要

Screening software has been developed to assess the economic feasibility of renewable energy alternatives for applications in Texas. The renewable options include solar water heating and PV and wind for electric power generation. A range of hot water applications, from swimming pool heating to process heat are permitted, and PV and wind energy may bo considered for either stand-alone or grid-connected use. The user inputs data such as application type, location, size of load, system cost, competing fuel cost, and discount rate. For the solar water heating options the software outputs the optimum collector area, life cycle savings compared to a conventional system, and a cost effectiveness index to assess economic feasibility. For the PV and wind options the software outputs life cycle savings, the average unit cost of delivered electricity, and a cost effectiveness index to assess economic feasibility. The software is designed as a screening tool, rather than design tool, and is developed for use with a spreadsheet program.form to allow quick and easy comparison of widely diverse energy alternatives. The economic analysis performed in the Texas Renewable Energy Evaluation Software (TREES) is a comparison of the life cycle savings for competing technologies. In general, the better prospects for cost effective renewable energy applications are passive solar heating, cooling, and daylighting, followed by solar water heating, and electricity from PV or wind energy. Other technologies and strategies, such as bioenergy, geothermal energy, and hydropower, are more limited in their applicability. The screening tools presented here are limited to solar water heating systems and photovoltaic (PV) and wind systems, because they are often economically feasible and their evaluations can be more easily generalized. A computer spreadsheet program, TREES, has been developed to predict the cost effectiveness of solar water heating systems, and of electricity from photovoltaic and wind systems. Figure 1 indicates the general capabilities of. the TREES software. More detailed documentation of its features, and the analysis on which it is based, can be found in Ref. 13.