Hartberg - Austria

Residential consumers
PV plants (MW)
Heat pumps
Home batteries


The town of Hartberg has long been committed to sustainable development. Now it shows why the smart city concept is attractive for small regions as well. Compact, with some 11,000 inhabitants, a historic town centre, and commercial areas on the outskirts: Hartberg in Styria is a typical small town. This makes it an interesting example of a smart city for other towns of similar size. There are concrete measures on the agenda of Smart City Hartberg, ranging from mobility and energy issues to participation. Within the current Smart City project, Hartberg is trying to act as energy sponge for the surrounding area by providing flexibility. Electric storages as well as heat storages are considered for the provision of flexibility. In Hartberg a range of aspects of Smart Grids are already installed or being installed in the near future.

Project description

Hybrid Grids DEMO

Purpose of the project is the development and the "Living Lab" test operation of a passive energy source- and network-wide distribution management (= energy sponge) over a particularly multipliable approach to harmonize network profiles, increase direct utilization rate of renewables in the project area and surrounding areas, increase efficiency in the generation / distribution and consumption as well as for comprehensive integration of renewables in the city of Hartberg. The focus of the project is a new approach: Central optimizer + passive network control + business model (new / local aggregation level) + Living Lab

Initial situation: The purpose of this project is the development and the "Living Lab" test operation of a passive energy source- and network-wide distribution network management over a particularly multipliable approach. The urban energy system should be converted into a functional energy storage, which can store large amounts of extra energy. Thus, both short-term surplus electricity and thermal energy deficits, as well as variations over months in sources of renewable energy can be compensated. The project therefore has a new project focus, and sets up where development and know-how is needed. This approach corresponds to the parent city vision, roadmap and action plan of the city, which would significantly reduce CO2 emissions and strengthen its own municipal utility with this project.

Problems: How the energy supply and energy utilization system of a city can be made more flexible so that the city can be used as big energy storage within the city and surrounding areas? Due to the initial situation there is a complex system with many degrees of freedom that needs to be optimized holistically and interdisciplinary. It causes legal, technical, economic and social problems.

Objectives: The priority goal is to develop and test the operation of an innovative, comprehensive and integrated energy sponge system for electricity, heating and cooling and their networks in the town of Hartberg. All energy networks (electricity, heating / cooling, gas) are optimized in real time.

Methodology: The focus is on a new technical approach through a central optimizer, which is implemented in parallel to the existing rule infrastructure and supplies the decentralized actors (producers and consumers) with recommendations and information related to this infrastructure. Thus, no active but a passive intervention in the sensitive network regulation is done with this approach. Based on that the current regulatory conditions are met and a demonstration of the envisaged system can actually be guaranteed.

The current regulatory framework requires not only a new technological approach. It makes it difficult to provide financial benefits to all different stakeholders (producers, consumers, network operators, trade). However, this does not apply to the project involved energy company, because it is not subject to unbundling due to the size. Thus new business models can be realized and financial benefits can be distributed without bypassing the current legal conditions. The entire project is handled by a Living Lab approach, intensive users integration and e-participation.

Aimed results and findings: (1) Realistic approaches to the implementation of a passive energy source - and network-wide distribution network operation (energy sponge), (2) the basis for a technology standard, (3) developed / adapted, tested and verified components, (4) test application; (5) experimentally recorded statements about the potential of "passive" actors as an integral part of an energy system, (6) survey of the potentials on energy sources - and cross-network degrees of freedom for parallel viewing of various useful energy consumers; (7) experiences / barriers / success factors; Through the project, corresponding CO2 savings can be provided directly by the demonstration objects, and in particular by further ecological effects on the operation as a functional energy storage (harmonization of the power profile, increase direct utilization rate of renewable in the project area and surrounding areas, higher efficiency in the production / distribution and consumption, comprehensive integration of renewable).

Carport with Storage




Use cases

Voltage Regulation

Some transformer stations are equipped with SIEMENS measurement units, measuring the voltage levels and current and evaluation within the control room – Currently no control possible

Energy Storage

  • PV-Carport with Li-Storage and EV-charging station
  • Decentralized and central storage devices (20 kWh) (incl. using the buffering effect of buildings and grids) at households and electrical transformer station

Demand Side Management

  • Different energy management systems (3 different brands) at household level currently in an evaluation phase
  • 2 industrial consumers controlled via load profile measure­ment unit and load shedding
  • Ripple control system for variable tariffs for heat pumps


Business models in development:
  • Integration of RES
  • Integration of storage capacities
  • Provision of new system services