Alteren Energy and Environment S.A. is an engineering consulting company, providing services in the areas of Energy and Environmental Analysis & Planning.

Alteren S.A. was founded in 1992 at Thessaloniki, Greece, by Professional Engineers experienced in Alternative Energy methods and systems such as Energy Conservation and Rational Use of Energy (RUE) for industries, SMEs and buildings, application of Renewable Energy Sources (RES), reduction of environmental impacts of technology and advance of new technologies in industry, agriculture and residence.