Field test of a virtual power Plant comprising 30 pellet-boiler fired micro-CHP modules

A virtual biomass plant comprising 30 micro-CHP-Modules, each of them integrated into an existing pellets-boiler in the Austrian region of eastern Styria is to be tested. The goal of this project is to gain experience and to introduce a new sustainable technology.

Short Description




Initial situation

The slightly higher rates, that are gained when supplying green electricity into the electricity network, make it feasible to operate biomass fired micro-CHP-plants on a economical basis.

Contents and Objectives

Objective of this project is the installation an the operation of a virtual power plant comprising 30 biomass fired micro-CHP-plants in the region of eastern styria.

A virtual power plant consists of several remote power-plant-units that are controlled by a centralised server unit.

The heat is produced by a biomass fired boiler with a capacity of 10 - 20 kW of heat. The electrical power is produced by a stirling engine (SPM-module) within the nominal range of 1 kW of electrical power.

The project should give the answers to technical questions like the effectiveness of the SPM-modules in practical circumstances - especially under partial load of the boilers, the controlling of the virtual power plant, the long term stability and maintenance.

In addition to technical matters there also should be examined the acceptance of renewable energy sources in general and the willingness of home owners to install such a new technology of electricity generation into their homes.

Applied methods

The SPM-modules are integrated into existing biomass boilers and heating systems in the households of the field test participants. Therefore in a first step suitable homes have to be chosen and on-site-inspected. Especially of interest is the ability for reconstruction work in the heating rooms, the electrical equipment and the heating system in those households. A contract between the SPM-GmbH and the home owners regulates aspects of financing, operation, maintenance and access rights. Furthermore each field test participant signs a contract with an energy supplying company.

In order to test the micro-CHP-plants under different operational circumstances households with different heating systems and peripheral devices are chosen.

The parameter list comprises of

  • Heat demand: Normal household or low energy house
  • Electricity generator: three phase asynchronous motor, three phase synchronous motor, DC-generator (if a DC-infrastructure is available)
  • Heating system: flow/return temperature
  • Hot water supply: hot water storage tank available or not
  • Solar thermal panel available or not

The controlling of the micro-CHP-plant and the analysis of the gained data is done via a central server based at the Institude Of Thermal Engineering, Technical University of Graz.

The long term stability of such a micro-CHP-power plant is right now tested on a test facility at the KWB Kraft und Wärme aus Biomasse GmbH with already more than 2000 hours of operation.

The first five micro-CHP-plants are to be installed during the winter season 2007/2008. The further 25 devices will be installed during the winter season 2008/2009.

Alongside to the field test further component testing is done at another test facility. The results gained there will be integrated into the field test plants as far as possible.

Expected results

The data from the field test micro-CHP-plants will generate useful experiences concering the performance and long term stability of the SPM-modules under real circumstances (partial load) and the optimised hydraulic integration of the SPM-modules into the existing heating systems. Both the optimizing of the components of the SPM-module as well as the optimizing of the whole power plant will be possible. The field test will also generate experiences for energy supplying companies how to operate a virtual power plant in a save and economical way.

Project Partners

Project management

DI Dr. techn. Karl Wolfgang Stanzel
SPM Stirling Power Module Energieumwandlungs GmbH

Project or cooperation partner

Contact Address

DI Dr. techn. Karl Wolfgang Stanzel
Nikolaus Schönbacher Straße 7
8052 Graz
Tel.: 43 (0) 316 581433
Fax.: 43 (0) 316 581427