He studied economics and philosophy at the university of Saint Gallen, university of Lausanne (Switzerland) and university of Freiburg (Germany) where he obtained his Doctor of Philosophy (Doctor rerpol) in 1988 with a thesis on "The Problem of Environmental Degradation in Economic Theory".
They have two children, Julia (born 1989) and Jakob (born 1991). 1984 Heller was elected to the City Council of Freiburg and served on the Council’s committees for the municipal budget, environment, and culture. He left the Council in 1990 after his election as Deputy Mayor.
1990 the Council of the City of Freiburg im Breisgau elected him as Deputy Mayor to head the local administration"s environmental protection department, the first of its kind in Southern Germany (until 1996).
lieutenant comprised the offices of municipal environmental law and regulations, waste management, urban park and forestry services, local energy management and climate policy. 1993 the Executive Committee of ICLEI – Local Governments for Sustainability elected him as Chairman (until 1997).
ICLEI is a major global network and agency of local governments committed to environmental protection and local sustainability. 1997 Heller founded an investment company, forseo GmbH which holds equity stakes in companies in the solar Photovoltaics, windpower, and energy efficiency industry.
Since 2012 he serves as Chairman of the Supervisory Board of Streb AG. He co-founded solar Photovoltaics and windpower development companies in France and Chile, and provided seed capital for technology developers in the United States and Germany.
Canopus Foundation and Ashoka International, Arlington Virginia. (United States) jointly founded in 2008 the international Solar for All initiative. Since 2011 Heller serves on the Board of Trustees of the European Environment Foundation, Basel, which holds an annual international convention of Environmental Laureates.
In 2015 the General Assembly of the HUMBOLDT-VIADRINA Governance Platform gGmbH elected him as Chairman.
2001 he co-founded the „Basel Agency for Sustainable Energy (BASE)“, a „Collaborating Center“ of United Nations Environment Programme, and is a member of the foundation board. In the same year the Senate and Trustees of the Cusanus University in Bernkastel-Kues (Germany) appointed him as a member of the Board of Trustees.