Renewable energy system design : a guide to the application of photovoltaic, wind, and micro-hydro power : a thesis submitted in partial fulfilment of the requirement for the degree of Master of Horticultural Science in Agricultural Engineering at Massey University, New Zealand

Abstract

The primary objective of this study was to produce a guide for the application of photovoltaic, wind, and micro-hydro power to remote areas. The applications considered are those of generating electricity, and pumping water. An extensive literature review introduces and covers the main design considerations for each energy form. The primary decision-making areas are then examined, beginning with a look at the theory of electricity, and going on to discuss generators, inverters, energy storage, and mechanical transmission. Next, the assessment of the demand over a given time interval is considered. The key questions of, "How big a system is required?", and, "How much energy will be produced?", are addressed for each energy form, along with various design considerations. For each of the energy forms the issue of quantifying the resource is examined in detail. The factors influencing the amount of power available are presented for each. This process of quantifying the power available is essential in order to be able to choose the optimum type of renewable energy to use for a given application in a specified location. Dealing with them together in one document allows the different energy forms to be assessed side.by side, and a preliminary decision on the most promising type made. For both wind and photovoltaic energy a computer model was created. drawing on available theory, in order to generate charts to assist in the design process. The photovoltaic design charts enable sunshine hour data to be converted to radiation in Kwh/m2, and radiation on a horizontal plane to be converted to that received on a plane inclined at a specified angle. Other charts were produced which enable the most cost effective combination of array and battery to be selected for a given situation. The wind charts specify the amount of power which can be produced from a wind turbine with given characteristics operating in a specified wind regime. The photovoltaic and wind design charts produced by the models enable the size of the relevant system required to be determined for a given situation. This information then allows a costing to be done to determine the cost of generating energy with a particular method. The procedure for evaluating and determining the true cost of the energy produced. based on life cycle costing, is then examined. This can then be used to assess the most economical means of meeting any particular demand.