The design of rural energy centres

Abstract

Need-oriented, self-reliant and environmentally-sound development demands that the design of rural energy centres proceeds step-wises from energy consumption patterns to energy needs to technological options to selection of energy sources and devices to integration of these sources and devices into a system. The procedure is illustrated with Pura village as a concrete example. There is first a description of Pura's energy consumption pattern, and its energy needs and energy resources. In the absence of a rigorous methodology for solving the fundamental problem of designing rural energy centres,viz., given the energy resources and requirements, what is the optimum way of harnessing i energy sources with the aid of j devices to achieve k energy-requiring tasks?, a heuristic approach based on second law efficiencies is used. The result is a design for a rural energy centre for Pura. The first phase of such a centre involves a community-scale biogas plant to meet the energy needs of cooking, domestic electric illumination, and pumping domestic water, in addition to providing organic fertiliser and producing rice husk ash cement. The Pura exercise is used to formulate several principles of rural energy system integration,viz., mixing, cascading and combining of sources, spatial task integration and time-sharing. Finally, the general problem of designing rural energy centres is mathematically formulated. The formulation highlights important data gaps which must be filled before rigorous rural energy system designing can be achieved.