• We have

    over 30 years

    of experience

  • [Translate to English:] Panorama Biogasanlage Dinteloord

    Over 150 references worldwide

  • [Translate to English:] Panorama Biogasnalage Anklam

    Engineering made in Germany


One-stop planning of biogas plants, from concept to commissioning, customised, competent, innovative and independent


Project experience in biogas in more than 40 countries, collaboration with reliable partners in 7 countries


150+ reference biogas plants all over the world, from 45 kWel to 8.3 MWel and experience with a wide range of substrate


08.07.2024 - KF continues to support active lifestyle and environmental protection

Engineering made in Germany

Krieg & Fischer Ingenieure GmbH is a planning office that focuses on the planning and construction of tailor-made biogas plants

The engineering office Krieg & Fischer Ingenieure GmbH is globally active in the biogas sector. Alongside the design, planning, approval planning (building regulations, BImSchG), execution planning, preparation and involvement in the awarding of the contract, overall management of the construction site and commissioning of the biogas plants, we also offer consulting services, prepare surveys, expert reports, insurance reports, studies and plant optimisation measures, inspect technical safety equipment and provide operator services and training courses – simply everything required in the biogas sector.


This includes simple farm-scale biogas plants for fermenting slurry, stable manure, energy crops and agricultural waste and also complex, multi-stage, industrial fermentation technologies for waste from the food industry, food leftover fermentation or organic waste fermentation plants. As well as the upgrading of biogas to biomethane and the further processing of the highly concentrated CO2 stream produced during upgrading (CO2 liquefaction).

We have particular expertise in the digestion of stillage from bioethanol production and residual materials from the sugar industry such as sugar beet pulp and vinasse.

Krieg & Fischer is an engineering office with an experienced team of biogas experts consisting of highly-skilled engineers. Our team works on an interdisciplinary basis, covering the areas of process and civil engineering, as well as environmental, energy and agricultural technology.


As publicly appointed and sworn experts for biogas plants, Raphael Thies prepare surveys e.g. for courts, insurance companies, authorities, lawyers and consumers.


We do not only possess experience with agricultural substrates such as slurry, manure, straw and other agricultural crop residue or various energy crops such as grass silage or maize silage but also with commercial waste such as kitchen waste, food leftovers, canteen waste, waste from the food industry, out-of-date foodstuffs from the retail trade, organic waste from industries such as fruit residue or marc and market waste such as fruit and vegetable residues or municipal organic waste such as organic waste bins or green waste etc. to name just a few.


We plan biogas plants that are adapted to the substrate and the local conditions. Our expertise stretches from substrate-specific pretreatment including, where necessary, the removal of unwanted materials or using additional hygiene and further conditioning steps, one and two-stage fermentation processes, mesophilic and thermophilic fermentation and wet and dry fermentation plants. Our fermenters are often high fermenters delivering optimal agitating properties to provide good value for money but also include flat fermenters with a gas storage roof or a plug-type flow system.


The biogas generated is used to produce electricity and heating in a combined heat and power (CHP) or combined cooling, heat and power (CCHP) process. Another possibility is to process the biogas into biomethane and feed it into the natural gas grid or use it as a renewable fuel.

Most of our biogas plants use the digestate in the form of a liquid manure as a replacement for mineral fertiliser and the recycling of nutrients. But we also have experience in processing the digestate to produce high-quality fertiliser, which can be sold, and dischargeable water.


We offer training courses to operators of biogas plants to enable them to continuously expand their expertise and also exchange knowledge amongst one another. We thus offer a platform for the transfer of knowledge and experience between the fields of research and teaching, operation and us as the planning engineering office.


We attach great importance to plant safety and occupational safety. Plant safety is an important factor in the planning, construction and operation of biogas plants.


The operation of a biogas plant requires owners to meet various legal, technical, biological and organisational requirements and possess relevant knowledge. Krieg & Fischer Ingenieure GmbH offers you a comprehensive range of services to support your operation. The goal is to reduce your workload and increase the plant safety and occupational safety of your biogas plant.

Biogas: the sustainable and decentralised way to generate renewable energy, treat organic waste and recycle nutrients to save on mineral fertiliser.


How can we help you further? We would be delighted to answer your questions. Get in touch with us!

Contact general

Krieg & Fischer Ingenieure GmbH
Maschmühlenweg 10
D-37073 Göttingen
+49 551 90 03 63 - 0
+49 551 90 03 63 - 29