The Centre for Renewable Energy Sources and Saving (CRES) is the Greek national Centre for Renewable Energy Sources (RES), Rational Use of Energy (RUE) and Energy Saving (ES). It is a public entity, supervised by the Ministry of Environment and Energy and has financial and administrative independence. Its main goal is the promotion of RES/RUE/ES applications at a national and international level, as well as the support of related activities taking into consideration the principles of sustainable development.