Krieg & Fischer Ingenieure GmbH is Specialised in Biogas Plants

Krieg & Fischer Ingenieure GmbH was founded on 1 January 1999 by Andreas Krieg and Torsten Fischer. We offer a full range of biogas services - from preliminary study to planning and construction through to commissioning.

Andreas Krieg designed and constructed his first biogas plant in 1986. During subsequent years he worked for general contractors and engineering offices. His work focused on agricultural biogas plants. In 1992 Andreas Krieg was co-founder of the German Biogas Association.

Torsten Fischer has worked in the biogas technology industry since 1993. Prior to the establishment of Krieg & Fischer, he worked for two general contractors. His work mainly involved industrial biowaste digestion plants and large-scale co-fermentation plants.

Raphael Thies already works for Krieg & Fischer since 2007. Starting out as an engineer in the field of planning and processing, he now also works in the field of sales. Alongside founder and shareholder Torsten Fischer, Raphael Thies will, as of 2017, take up the position of an additional Managing Director.

Krieg & Fischer therefore has extensive experience in the planning and construction of biogas plants. Our expertise covers one- and two-stage, mesophilic and thermophilic, wet and dry fermentation plants. Liquid manure, dung, renewable raw materials, biowaste, kitchen waste, fats, organic sludges and many other forms of organic waste are treated in these plants.

Key points in our company history since 1999


  • Alongside founder and shareholder Torsten Fischer, Raphael Thies will, as of now, take up the position of an additional Managing Director.


  • Service offer is expanded by the two new business areas Energy Consulting and Occupational Health and Safety Consulting including services like TRGS 529 seminars and in-house training for biogas plant operators
  • Our employee Raphael Thies was sworn in as Krieg & Fischer's second publicly appointed expert for biogas plants by Lower Saxony's Chamber of Engineers (19th July 2016)


  • First biogas plant in China begins operations in August 2015 (Quinhuangdao)
  • First trade fair performance in China (Sino-German BioEnergy in Guangzhou
  • Service offer is expanded by a qualified Health and Safety Officer according to § 7 Health


  • Consulting and construction of a Sino-German biogas demonstration project on behalf of GFA financed by BMEL
  •  2014 First partizipation in the NExpo trade fair in Tokyo, Japan


  • Start of construction work of the first biogas plant in China
  •  First agricultural biogas plant is constructed in Argentina
  •  Consultation on World Bank projects for designing biogas plants in China


  • Construction of the first biogas plant in Russia
  •  Entry into large-scale industrial sugar beet fermentation in the Netherlands and Germany


  • Consultation on biogas projects in China in conjunction with GIZ
  •  Celebration of the company's 10th anniversary with an official speech by Jürgen Trittin. Over these 10 years 125 plants have been designed and implemented. The number of employees has increased to 17
  •  Move to a larger Office at Bertha-von Suttner-Straße 9 in Göttingen


  • Torsten Fischer is sworn in as the first publicly appointed expert in the field of biogas by the Chamber of Engineers of Lower Saxony on 24 March
  •  Construction of the first biogas plant in Ireland
  •  Construction of the first biogas plant with gas processing and feed-in into the natural gas grid

2008 - 2011

  • FNR combined research project: FKZ 220 14308: Mono fermentation of corn silage from locations with differing soil conditions


  • Andreas Krieg receives the Heinz Schulz Medal of Honour of the German Biogas Association
  •  Construction of the first biogas plant in France


  • Construction of the first of 9 biogas plants in Spain
  •  Torsten Fischer takes over the sole management
  •  Construction of the first biogas plant in California


  • Construction of the first biogas plant in Canada


  • Innovation Award of the district of Göttingen for the fermentation of energy crops without adding liquid


  • Development of the first energy crops plant where no liquid was added (Obernjesa/Bioenergiehof Obernjesa)
  •  First biogas plant constructed in Austria


  • First biogas plant constructed in Italy


  • Construction of the largest biogas plant of its time (8.4 MW) in Wietzendorf
  •  First biogas plant established in Japan
  •  First biogas plant constructed in the Netherlands


  • Krieg & Fischer Ingenieure GmbH was founded



Swearing-in ceremony Torsten Fischer as expert witness in the field of biogas
10-year anniversary of the firm
Andreas Krieg is Awarded the Heinz Schulz medal of honour from the German Biogas Association (2007)
Innovation award 2003 for the biogas plant Obernjesa (Krieg, Körber-Harriehausen, Fischer)