EnergyTransformation In physics an engineering,energy transformation or energy conversion,is any process of transforming one form of energy to another. Energy of fossil fuels, solar radiation, or nuclear fuels can be converted into other energy forms such as electrical, propulsive, or heating that are more useful to us. Often, machines are used to transform energy. The efficiency of a machine characterizes how well (how efficiently) it can produce a useful output (such as work for example) through such a conversion. Energy transformations are important in the application of the energy concept in various natural sciences including biology, chemistry, geology and cosmology.