Twentieth century has witnessed the emergence and wide acceptance of Solar, Wind, Biomass and other Renewable Energy Technologies (RETs) as reliable means to bridge the gap between the mounting global energy demand and the dwindling supply of finite conventional energy sources. The popular awakening regarding a cleaner environment at the global level further boosted the development of technologies for utilizing the widely available and the almost inexhaustible renewable energy sources. The different sectors of energy consumption have adopted them with varying degree of success in particular, the industrial sector has developed enough confidence in employing RETs for energy conservation, which is an important component of overall energy management. However, the real benefits of these RETs have remained inaccessible to large sections of the global population because of the uncompromising economics of harnessing them for large scale application. Consequently, international efforts are now centred on maximising the efficiency and minimizing the coat of RETs.