Decentralized Energy Concepts for Smart Buildings in Smart Grids - Project Introduction Aspern, Vienna's Urban Lakeside

The smart city is growing in popularity as the need for sustainability and energy efficiency escalates. We asked a panel of industry experts for their input and Aspern Smart City project was used as an example.
Published: Tue 01 Apr 2014

One of the biggest challenges in the creation of a smart city, regardless of the location, is the vast number of stakeholders involved. This is according to Dr Sascha Brozek, Senior Vice President and Global Head Building Technologies - Systems & Solutions, Siemens Switzerland Ltd, in a recent Engerati webcast. These stakeholders include utilities, facility management firms, contractors, project developers, various types of suppliers, ICT companies, and most importantly, commercial and residential tenants.

A reliant coherent ecosystem

However, the Aspern Smart City Project is unique in that its stakeholders all tend to move in the same direction with regards to research and development, explains Dr Brozek. He explains, “The unique thing about the Aspern Smart City Project is that it is a very reliant coherent ecosystem. This is what makes the project unique when comparing to other commercial smart city and grid pilots around the world. There is a common understanding amongst stakeholders that are contractually aligned.”

Some of the players involved in the project include Wien Energie, Wiener Netze, Siemens (Wien 3420 Aspern Development AG, and Business Agency Wien.

More about the Seestadt Wien Aspern-Vienna’s future smart city district

The project, launched one year ago, aims to realize a high quality living standard through the development of a smart city where high efficiency technologies are installed throughout the city. This is according to Mr Christoph Gerstbauer, Sales and Product Management, Energy Efficiency, ENERGIECOMFORT GmbH, Austria.

It is one of the biggest smart city projects in Europe-there will be enough apartments and commercial space to accommodate 20,000 inhabitants until 2030. The new multifunctional smart city also provides business and research quarters and a school campus. In addition, it addresses megatrends in urbanization and climate change.

The future-oriented concept includes technologies, products and solutions for an energy efficient city district.

Smart City Focus areas

When building a smart city, systems integration is critical to its success, explains Mr Gerstbauer who lists various areas of focus, each essential to the overall system:

  • Security of supply-Energy must always be reliable and affordable.

  • Low voltage grid control-In the future, millions of small power producers will feed electricity into the grid. The low voltage grid provides stability in the network and balances production and consumption.

  • Energy storage-Since wind and solar energy supply is irregular, power storage and management is necessary.

  • Efficient energy usage-Reduction in energy consumption, intelligent control and energy management of multi-model distribution networks and building management will lead to high savings.

  • Consumption control-Demand management of power consumption in real-time is essential for the adaptation to price fluctuations. This is where smart technology plays a critical role.

  • Renewable energy-The integration and management of renewable energy sources will help to reduce carbon emissions and increase energy efficiency.

Future facility manager tasks-from building technician to building energy manager

According to Mr Gerstbauer, the building energy management system of today should focus on:

  • The development of optimization strategies of self-consumption and power procurement.

  • Forecasting-Weather forecasting, for instance, helps decision-makers to react appropriately.

  • The analysis of energy flow in a building.

  • Monitoring-This involves alarm handling-simulation and forecast-optimization-buy/sell strategies.

The smart city’s power system should also support the participation in energy markets. If electricity is cheap, it can be used to heat up buildings or as energy storage in storage tanks. However, if the electricity price is high, energy tanks can be “de-loaded” or there can be a reduction in energy production from the energy plants.

Smart infrastructure for decentralized energy concepts

PV, solar panels, heat pumps, 150KWh electricity storage tanks (a battery-based storage solution), thermal storage tanks, air-conditioning which can be influenced, district heating, lighting control, sunblind integration, building automation and management and room control have all been added at various sites within the smart city.

The smart city uses ground water, exhaust air, thermal and solar as energy sources. Thermal solar energy is put in the soil and is then taken out with heat pumps when required. Exhaust air is used for heat pumps and there is also a huge storage tank with a 150kwh capacity for photovoltaic solar. Storage tanks will be loaded and “de-loaded” according to the prevailing market price.

The idea is to influence indoor air with sunblind integration, building automation and light control. Photovoltaic and solar is used as an energy source for underground heat pumps, underground water and exhaust air.

Air flow of rooms are monitored by “room control”-carbon emissions are monitored and air is adjusted accordingly.

If storage tanks are full due to photovoltaic solar, the excess energy can be used to heat domestic water supply.

Optimization is focused on heavily so that no energy goes to waste, says Mr Gerstbauer.

Total Building Solutions-efficiency enabler through integration

One of the preconditions for the realization of this energy concept is an integrated approach, explains Vesna Mikulovic, Sales Manager, Total Building Solutions, Infrastructure & Cities, Siemens Austria. She goes on to explain that integration planning is what makes the project so unique. Planners, developers, architects, energy concept developers and building experts were involved from the very beginning.

“All role players must be involved from the beginning so that the concept of the smart building can be developed together.”

The “total building solution approach” is a method which is proving to be highly efficient. It’s not only about energy savings in respect of Kwh-it is also about energy cost savings from the perspective of energy consumption optimization and maximization of self-produced energy usage.

“The idea is to establish a complete integration of systems-including security systems-thereby creating a one-management station which represents a single entry point for the efficient interaction with external systems

Smart buildings manage optimally local consumption, generation and storage by providing detailed monitoring

Residents’ existing comfort levels should not be interfered with, explains Ms Mikulovic. “This is one of the project’s highest priorities. All the smart city energy concepts have been developed to enhance residents’ comfort levels.”

The city’s high energy efficiency plan incorporates the usage of renewable generation but it also includes a combination of storage, generation and consumption. This will all lead to a highly energy efficient system.

In addition to this, all buildings in this smart city will have a high level of sensor integration. The sensors will provide an accurate forecast on energy consumption, as well as generation levels.

Ms Mikulovic lists the smart building components:


  • Energy efficiency-Energy consumption is reduced but at the highest comfort levels only, thus improving sustainability. Concepts include heat generation with heat pump, air distribution, temperature control with blinds, and brightness control with lighting.

  • Smart building-The aim is to create a total building solution which includes local energy generation and storage, optimal power management of generation, storage and consumption, as well as e-mobility and effective communication with the smart grid.

  • Monitoring, controlling and forecasting a building’s processes. This will help to interpret monitored data so that consumption, generation, and storage can be forecasted.

Says Ms Mikulovic, “This project should give us insights as to how buildings of the future should be built.”

Seestadt Aspern-Smart City living lab

Mr Gerstbauer lists concrete steps towards the creation of a smart city:

  1. Development and implementation of systems in a real city environment should go hand-in-hand with integrated district planning (spatial planning, energy planning and mobility planning)

  1. Demonstration of the performance of these systems:

  • Access to real data of customers, buildings and networks
  • Direct feedback from citizens, building operators and energy suppliers

  • Risk minimization during the development of customer proximity and real environment (reduced time to market)

  • Better use of the innovation potential through the participatory approach of all stakeholders


The life-cycle cost assessment on this project indicates that a 20-30% savings can made. This is related to the total billing saving based on a standardized solution without the integrated approach. Additional cost savings can be made from new optimization strategies. Ms Mikulovic points out that optimization strategies that are more innovative, are expected to save even more money.”

Utilities have a major role in the establishment of a smart city. Ms Mikulovic explains that it is essential that all the innovative energy supply offerings are explored thereby creating a real market environment which allows the demonstration of these projects. “Without this relationship, it leaves us in a “playground” environment. We must have all the energy suppliers onboard.”

A growing interest in “Green Cities”

According to Mr Brozek, large companies have corporate policies in place to encourage low costs. But, they are also beginning to see the importance of occupying a building with sustainability aspects. Many firms expect aspects of a corporate building to meet sustainability targets. Green building certificates were created in response to this need about 10 years ago and forms part of many firms’ corporate policies.

Ms Miculovic points out that the need for highly efficient cities is growing rapidly. She says that developers are overbooked since both the commercial and residential sectors want to stay in highly efficient green cities.

She points out, “People and businesses are willing to move into new “green cities” even if they have to wait 10 years for new developments to be completed.”