In mankind's relentless quest for prosperity, Nature has suffered great damage. It has been treated as an inexhaustible reserve of resources. The indefinite scale of global expansion is still continued and now the earth's very survival is under threat. But against this exploitation of nature, there is a concept of Entropy that places a finite limit on the extent to which resources can be used in any closed system, such as our planet. Considering the impact of entropy, this book examines the key issues of sustainability-social, economic, and environmental. It discusses the social dimension of sustainability, showing how it is impacted by issues of economic inequality, poverty, and other socio-economic and infrastructural factors in the Indian context. It also highlights how Indian households suffer from clean energy poverty and points to the inequality in distribution of different fuels and of fuel cost among households. It assesses India's power sector and its potential to be a significant player in bringing the third industrial revolution in India by replacing fossil fuels to new renewables. It concludes by projecting power sector scenarios till 2041-42 achievable through alternative, realizable policy with respect to energy conservation and fuel substitution, and thus paving the way for the green power.