Community-Based Independent Power Plant: A Case for Renewable Energy Resources. C.A. Nwosu, M.Eng. 1* , G.C. Asomba, Ph.D. 2 , and C.U. Ogbuka, B.Eng. 1 1 Department of Electrical Engineering, University of Nigeria, Nsukka, Nigeria. 2 Department of Physics and Astronomy, University of Nigeria, Nsukka, Nigeria. * E-mail: cajethannwosu@yahoo.com grg_chira@yahoo.com ucogbuka@yahoo.com ABSTRACT Theoretical analysis of how wind power can be complemented by hydropower with pump storage to provide firm and all green power is presented. A battery sub-unit comprising battery banks and current source inverter provides the needed reactive power for the magnetization of the wind/hydro turbine generators and the load. A reactive power compensator is included to offset any reactive power imbalance between the sources and the sinks. A case study of wind and small hydropower capacity potentials in surveyed states in Nigeria was highlighted to accentuate the applicability of wind-small hydropower hybrid power plant in these locations. (Keywords: wind power, hydroelectricity, hydro power, small scale, renewable energy, pump storage) INTRODUCTION Several questions and arguments have been raised about the viability of renewable energy resources as an efficient substitute to fossil fuels. The usual arguments center mostly on the factors which include: capacity credit, ready availability, dispatchability, etc., of the renewable sources when compared to the conventional sources. The literature addressing the adverse effects of the conventional sources in our environment abound. Most of the renewable resources, especially wind potential, are stochastic and this may be a contributory factor to the slow renewable resources penetration of the energy system. Consumer energy demand fluctuates on daily and seasonal bases, a factor which restricts the use of renewable energy sources for satisfying alone, without energy backup, the ever increasing energy demands of the consumer. There are periods when these stochastic sources are in abundance and when they are unavailable. Since electricity is very difficult or expensive to store in large quantities, it must be produced exactly at the it is consumed. Several schemes in electricity generation have been proposed in order to respond to instant fluctuations in electric power demand. Kaldellis, et al. [1], evaluated the wind-hydro energy solution for remote islands, which consisted of an interconnected wind farm, a small hydroelectric plant, a water pump station, and two groups of reservoirs. In this hybrid system, the surplus energy is stored by the water pumping system. Bakos [2], analyzed the operation of a wind farm combined with a reversible-hydro power station and a parallel water pump station. When an energy surplus is produced during the operation of the system, it is diverted to the water pump station that carries water from lower tanks to a higher level and stores it in the form of hydrodynamic energy. In another study where wind energy is added to hydropower [3], the wind power is interconnected to the grid and the hydropower is used to compensate for the wind power fluctuations in the context of a global energy balance. In reference [3], hydropower provides the backup capacity. In reference [2], autonomous power stations (APS), which consisted of diesel engines, provided the needed backups. The use of APS as backups stems from the anticipation that even though wind and water power, two variable resources, have the potential to complement each other there may be a season of lack of energy from the hybrid system. The Pacific Journal of Science and Technology –452– http://www.akamaiuniversity.us/PJST.htm Volume 9. Number 2. November 2008 (Fall)