There is a great interest about climate changes impacts on energy sector, because energy has a fundamental role in supporting all human activities. Energy system is strongly linked to local climatic conditions. In fact, temperature and precipitation changes affect both energy use and energy production: fossil power generation lose efficiency if temperatures increase; hydroelectric generation decrease with reduced water supply, typically in drought periods; renewable power generation is prevented and energy distribution system is reduced if temperatures and precipitation storminess increase. Climate change projections over the Mediterranean region have been elaborated from regional climate change simulations. The analysis considers temperature, precipitation, wind, solar radiation outputs of ten simulations selected from ENSEMBLES data-set at different time scale with focus over Italy. Projections for the thirty-year period 2021-2050 have been elaborated considering as reference period 1961-1990, after some model validations have been performed for the years 1961-2010 using, as reference values, gridded data provided by ECA&D project. Despite some uncertainties due to the spread of the models, a significant warming (ranging between 1.2 and 2 degree) is projected, above all in the summer season with a greater occurrence of extremely high temperature events. About the precipitation, it is found a likely precipitation decrease in the Southern of Europe of about 10-20% in the summer season. Heating degree days (HDD) and cooling degree days (CDD) have been calculated in order to examine the change in energy requirements. HDD decrease substantially in the Europe, CDD increase everywhere in the Mediterranean.