This article covers energy saving technologies and alternative energy sources. Scientific research work on the impact of energy on the environment presents problems and solutions. Energy is an essential element in all productive processes. In both the agricultural and transformation industries, however, its irreplaceable importance is often underrated. Alternative sources of energy which are irreplaceable can have a direct impact on the environment and does not seem to be sustainable to meet the future demands of human beings. This article is meant to be a brief guide to energy sources and technologies.