The Ochain Energie biogas plant project could serve as a model example of how cogeneration can be optimally used in agriculture. It is proof that low-emission production of power and heat from locally sourced waste is worth exploring.
The main motivation of the owners was the construction of a renewable energy source without a negative impact on the environment and nature.
“It all started very simply, we wanted to find another source of income for the family farm. However, we did not want to embark on the path of industrial automation in livestock farming. Agriculture must be approached with respect, with an open mind and one must also be prepared for new trends in this field. Biogas in combination with cogeneration is beautiful proof of that.”
Mr. Grégory Racelle, owner of the family farm
In a biogas plant, biomass is mixed in the fermenters, heated in a controlled manner, and subsequently decomposed. This decomposition produces biogas with a high proportion of methane. A notable factor of this project is the commitment of the operator that the input raw material – biomass – is supplied only from local sources, which contributes even more to the low-emission concept. The resulting biogas, which is cleaned of unwanted impurities such as water or sulfur dioxide, is used as fuel for the CHP unit. Moreover, the whole cycle is a closed loop. After the fermentation process has ended, the entire content is further used as fertilizer. This is done because the substrate does not lose its quality during the fermentation process. Each farmer eventually receives the same amount of digestate that they originally put into the biogas plant.
Each of the TEDOM cogeneration units has an output of 600 kWe at a consumption of 430 Nm3 of gas per hour. The electrical efficiency of the system is 42.8% and the total efficiency reaches 89%. The biogas plant consumes approximately 36,000 tonnes of biomass per year. Thanks to this technology, about 6,000 tonnes of CO2 are saved per year. The power produced from one cogeneration unit per year would be enough to cover the consumption of about 3,000 households. Thanks to the capacity of the large storage, it is possible to operate the cogeneration unit for 24 hours a day, with only small service breaks during the year. The result is a truly green, local and highly efficient stable energy output.
The power from the two cogeneration units is primarily supplied to the grid, covering part of local power consumption, and providing additional income for the farm. A small part of the heat is used to regulate the temperature in the fermenters to guarantee the correct decomposition of organic matter. Most of the remainder of the heat is then distributed by a heat pipeline to a local nursing home situated approximately a kilometer away. It covers all the heating and hot water requirements for approximately 120 people in the nursing home.
Benefits of cogeneration
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About 6,000 tonnes of CO2 saved per year |
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3,000 households supplied with green electricity Local nursing home supplied with green heat |
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1200 kWe Electrical output 89 % Overall efficiency |