Hans-Josef Fell authored the draft Renewable Energy Sources Act (EEG), which was adopted in 2000 in the face of strong political opposition. He was also involved in drafting the law amending the EEG in 2004. The EEG is the foundation for the technology developments in photovoltaic, biogas, wind power and geothermal energy in Germany. The underlying principle of the EEG has since been replicated in almost hundred countries around the world. Hans-Josef Fell initiated the legislation exempting biofuels from tax and was actively involved in establishing the renewables legislative at the European level.
From 1999 to 2005, as spokesman of the Alliance 90/the Greens parliamentary group in the research committee of the German Bundestag, Hans-Josef Fell helped to secure an increase in research funding for photovoltaics, concentration solar power, geothermal energy, bioenergy, batteries for electric cars, bionics and nanotechnology. This funding was crucial for the current worldwide expansion of solar thermal power technology and for the expansion of geothermal power generation throughout Germany.
As a member of the Bundestag Defence Committee, Hans-Josef Fell supported the development in military training methods towards conflict de-escalation. This training on violence prevention during military operations has attracted international recognition, particularly at the level of UN peace operations.
Hans-Josef Fell studied physics and sports and was a grammar school teacher from 1978 to 1998. From 1990 to 2000 he was a city councillor in Hammelburg and a district councillor in Bad Kissingen.