Technological developments made the energy of any form as important part of our lives and its importance as resource is increasing with the time. Nowadays many factors are contributing to the increasing spreading of renewable energy sources: the increasing energy demand, the decreasing availability of the fossil fuels, the increasing problems related to pollution and an unsustainable lifestyle. Photovoltaic and wind turbine technologies represent alternatives with high spreading and good development opportunities. This work primarily treats method for renewable energy calculations and their financial and effect to environment. Formulations, data source and brief explanations of concepts have been collected in systematic way.