Voltage stabilization by central reactive power control of biogas power plants (Virtual Biogas Power Plant)

A virtual power plant, combining 20 agricultural biogas plants is planned in the south-eastern part of the State of Styria (A). The aim of the project is to realize a central reactive power control system of the biogas plants. Active power of this biogas plants ranges between 1 and 3 MW. Specific goals of the project are increasing grid stability, decreasing long distance reactive power transmission, decreasing energy losses, and decreasing utility costs.

Short Description




Electrical energy from biogas plants usually is fed into the public grid. Due to the fact, that biogas plants normally have a gas storage with at least a 1-day capacity of biogas, they are suitable to adapt the energy fed into the grid to the current requests respecting both:

  • 1. Active power (adaption to the load curve of the grid)
  • 2. Voltage resp. reactive power (by controlling the field current of the generator)

Up to now, at the best the first possibility has been used only. Requests of grid control and grid stability have not been respected.

The aim of the current project therefore is the development of a concept to prepare and to initiate a model system for a certain number of biogas plants, which should be connected together, building a "virtual power plant". This "virtual power plant" is centrally controlled in the viewpoint of optimized grid control for both, active and reactive power. To realize such a system, specific knowledge concerning relevant technical, economical and at least legal details is needed, which has to be prepared in the subject project.

  • The project contains 4 main tasks
  • Task 1: System analysis model development
    In Task 1, a basic concept of a model system for grid stabilization by interconnected biogas plants will be developed. Technical and economical boundary conditions will be investigated. Technical measures, necessary for interconnection of some 20 biogas plants will be specified.
  • Task 2: Life Cycle Analysis
    In Task 2, a Life Cycle Analysis of the model system will be carried out
  • Task 3: Workshops
    A start up workshop with owners (operators) of biogas plants and grid operator STEWEAG-STEG is planned. In this workshop the details of the project work will be discussed and decided.
    In the later stage of the project, a further workshop is planned with representatives of possibly subsidizing governmental institutions and political decision makers is planned. In this workshop, details of the later planned realization of the model system as a demonstration project will be discussed.
  • Task 4: Preparation of a demonstration project
    In task 4, STEWEAG-STEG and interested owners/operators of biogas plants will enter into preliminary negotiations about the details of the model system and the details of the model system will be specified.

The expected result of the subject project is a concept for model system of a "virtual biogas power plant". The concept will contain a list of interested partners (owners/operators of biogas plants), a technical specification of the model system, an economic analysis, and an analysis of the possible benefit for the climate protection (green house gas balance).

Project Partners


Dr. Reinhard Padinger


Joanneum Research Forschungsgesellschaft mbH

Dr. Reinhard Padinger
Elisabethtrasse 5, 8010 Graz
Telefon: 0316 876 1333
Fax: 0316 876 1320
E-mail: reinhard.padinger@joanneum.at
Website: www.joanneum.at

Project- and Cooperationspartner

  • Bio Energie Ratschendorf GmbH
  • Ökostrom Mureck GmbH
  • Bioenergie Lukas-Pfeifer-Tscherner GmbH
  • Kohlroser Biogas GmbH
  • NEGH Biostrom KEG
  • Biokraft Hartberg Energieproduktions GmbH