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Abstract: Global exploitation of renewable energy technologies is increasing rapidly due to the concern in global warming and dwindling supplies of fossil fuels. Most of the countries in the world are blessed with two or more renewable energy sources (RES) and hence have formulated policies to boost the utilization of RES for their electricity production. An assessment of renewable electricity scenario is essential for research and development related works in the field of renewable energy technologies in order to further develop the renewable energy industry. Recent developments in installation capacities, costs and reductions in electricity costs of major RES based electricity generation methods are discussed in this paper. It also includes the past growth and future expectations of renewable electricity production. The analysis shows that if the current developments in renewable industry continue, then a major share of global electricity production in the future could be supplied by renewable energy technologies. The analysis further shows that a significant amount of fuel cost and pollutants emission can be reduced by the increased use of RES based electrical power production technologies. [Copyright &y& Elsevier]

Abstract: Good grounding arrangement is very important for safe and reliable operation of a power system and to ensure safety of the power apparatus as well as the operating personnel. In most of the inland arid desert areas, the soil resistivity is significantly high and it is difficult to get low earth resistance with conventional methods. Therefore, an economical and efficient grounding system design of the earthing pit is necessary which can be achieved by using a low resistivity material (LRM). When such material is used, it is important to optimize the pit design. The grounding resistance for different configurations were calculated and based on the results, an optimized pit configuration is discussed. The intent of this paper is to present a simple general computational technique for finding the optimum economical size of grounding pit when filled with LRM. It was found that the use of too high volume of LRM does not reduce the earthing resistance in a corresponding manner. The suggested method can be readily used by engineers to obtain a good earthing pit configuration for efficient grounding of the power system components in high resistivity soils. [Copyright &y& Elsevier]