ERA-NET Small-scale BM based CHP  

General Project description:

The by far most common biomass CHP technology applied are large-scale steam turbine cycles with electric capacities of some MW. In the medium capacity range the ORC (Organic Rankine Cycle) technology with nominal electric capacities between 400 and 1,500 kW has successfully been established during the last two decades. For the small electric capacity range so far no technologically sound (in terms of efficiency and reliability) and economically affordable biomass CHP technologies are available. Therefore, the project aims at the further development and test of new CHP technologies based on small-scale biomass combustion systems in the electric capacity range between some W and 100 kW. The development is based on basic R&D already performed for promising new technologies and aims at the achievement of a technological level within the project which allows a first commercial demonstration after project end.
The main objective of the project is to develop and test three different CHP concepts in different capacity ranges which are suitable for different types of small-scale biomass combustion systems. These are

  • for pellet stoves a thermo-electric generator (TEG) concept with a power range of 25 to 50 Wel,
  • for small-scale biomass boilers a micro-ORC process with a nominal capacity of about 1 kWel as well as
  • for larger woodchip and pellet boilers a micro CHP system based on a high temperature heat exchanger (HT-HE) and an externally fired gas turbine (EFGT) with a capacity range of 5 to 100 kWel.

The workplan is based on CFD (Computational Fluid Dynamics) supported development and design of the different technologies, dedicated experimental research as well as construction and test of prototypes. One work package is considered to support all others with information and experiences regarding alkali release, ash and deposit formation, corrosion as well as combustion stability of fixed fuel beds (essential for stable CHP operation) since these are central issues for all 3 technologies.
In order to reach the objectives outlined and to implement the workplan, a consortium of in total 8 scientific partners from 5 countries (4 of them participating in ERA-NET) as well as 4 company partners has been formed. The consortium consists of experienced scientific institutions, an engineering company (specialist on small-scale CHP systems), biomass stove/boiler manufacturers and a CHP technology provider. Therefore, all expertise needed for the R&D work proposed is available from the project partners.
At the end of the project the technologies shall reach demonstration stage and first units shall afterwards be installed at selected users for field testing. Within another 3 to 5 years serial production could be initiated. As soon as the new technologies are introduced into and established on the market, they are expected to have a significant industrial and environmental impact. According to ETP-RHC, presently about 8 Mio. small-scale biomass boilers are installed in Europe and the newly installed boiler systems amount to 300,000 per year. Assuming that in future around 20% of these systems could be CHP systems, a huge potential of 60,000 plants per year results.