The process is based on the anaerobic digestion of biomass. The proposed digester technology for the project is a so-called High Performance Temperature Controlled (HPTC) biogas plant. The HPTC, in contrast to the conventional one-stage digester, is a 2-staged digester in which the process of hydrolysis/acidification and methanisation is taking place in separate tanks. Main advantages include a substantially higher (20-30%) biogas yield and more importantly the HPTC allows the efficient use of different, mixed organic substrates that are difficult or impossible to digest in conventional plants.
The following diagram is a simplified presentation of the two-stage HPTC digester:
- small sized plants from 10 to 60 kWel or to provide cooking gas
- robust, simple components with low degree of automation
- generated for rural areas in developing countries which are not connected to the electrical grid
novis small biogas plant (HiPo-S) in Benin, novis GmbH 2010
- medium sized plants from 100kWel to 1MW
- typically used in the agricultural field
- fully automated, reliable biogas plant for feeding into the electrical grid
- including a heat recovery concept
- particularly suitable for substrates heavy to use like manure, grass silage, or often changing substrates
250 kWel biogas plant in Zarchlin, northern Germany, novis GmbH 2012
- extra large plants bigger than 1MWel
- used in the agricultural field, for food products, or for bio-waste
- operational safety is ensured by the redundancy of the technical system
- feeding in the electricity- or natural gas-grid
2 MWel biogas plant in Simbach, southern Germany, novis GmbH 2002
The produced electricity is distributed to the villages via 10 kV lines. In the villages a 400 V underground grid is used to supply the households with 240 V AC.
Every household has a measure-and-control unit which is activated with a pre-paid card. These cards can be charged at the local bank.
All installations are according to German standards; there are no cut backs when it comes to safety.
The following diagram shows a rough outline of the grid: