Integrated energy planning: Part I. The DEFENDUS methodology

Abstract

The process of energy planning involves the estimation of future energy demand and the identification of a mix of appropriate sources to meet this demand. This mix must emerge from a rational procedure in which various energy generation and/or saving options are evaluated. A powerf ul, simple and transparent approach to energy planning -- the development-focused end-use-oriented service-directed (DEFENDUS) approach -- is discussed here. Demand for a source of energy is based on the services for which it is required -- the extent to which such services are spread among the population and the efficiency with which they can be delivered. The energy requirement so estimated is then matched with energy-supply and/or energy-saving options, so as to minimize costs. Starting with the reference energy system (RES) -- the energy system as it obtains in the present (or the most recent past for which data is available) -- the DEFENDUS approach constructs scenarios of future energy demand, paying deliberate attention to the equity and energy-efficiency considerations of alternative scenarios. The costs per unit of energy supplied/saved are then estimated, including both investment and operating expenses as well as the costs of delivery to the consumer and the losses in distribution. Environmental impacts -- and the cost of mitigatin g them -- can be taken into consideration in the methodology. The economic impacts of a chosen scenario can also be included. By ranking the energy supply/saving technologies in increasing order of costs, the least-cost mix is obtained. Whereas with most pre-programmed packages, the planner must accept the format already provided, the DEFENDUS approach suggested here enables one to validate every step of the computation procedure and modify assumptions according to the actual case being considered. The first part of the paper deals with the methodology proper. It refers to the reasons for developing such an energy-planni ng method, sketches a conceptual framework and then discusses the actual procedure in detail, including the usage and advantages of spreadsheets for computation. Part II (to be published in the following issue) will elaborate on examples of DEFENDUS scenarios.