In the present global energy scenario, renewable energy resources have become important topics from both the economical and environmental points of view. The present book, therefore, discusses Global and National status of renewable energy resources, and provides a platform to understand the basic principle, applications, modeling, energetic and economic analysis of renewable energy resources namely solar, biofuels, biomass, biogas, wind, hydropower, geothermal, waves, ocean, tidal and animal energy resources etc. The basic principles of heat and mass transfer and thermodynamic cycles in biopower generation have been discussed. Environmental impacts of renewable energy sources have also been discussed.