Modern interest in renewable energy development is linked to concerns about exhaustion of fossil fuels and environmental, social and political risks of extensive use of fossil fuels and nuclear energy. It is a form of energy development with a focus on renewable energy. In this sense, the present work takes part in a global study of solar energy and wind power for generating electricity. This paper is focused, by means of time series analysis and Kohonen self organizing maps, on predicting short-time electric consumption for a family of four people living in the south of France (Perpignan city). A cost study for the installation at the family's house of photovoltaic solar cells and/or windmills for generating electricity was also carried out. Lastly, the produced electricity cost was compared with the price of electricity sold by the French national company Electricité de France (EDF).