Research in focus

An energizing message

Though Johannes Schrade neither holds a political office nor a high-profile position in industry, he is yet actively involved in shaping the future of the city of Stuttgart. The ambitious scientist of the Fraunhofer Institute for Building Physics IBP is committed to improving energy efficiency, and he is right at the forefront when it comes to enhancing the Swabian capital's energy performance. In Stuttgart, the topic of energy efficiency is given high priority, as the city has set ambitious goals: By 2020, Stuttgart aims to use 20 percent less energy than in 1990, with renewable sources of energy covering at least 20 percent of the energy demand. Based on 2012 data, this corresponds to a volume of 900 million kilowatt hours of primary energy, which will be saved. This corresponds roughly to the annual amount of energy used by an average Stuttgart citizen for heating his home. The competition "Energy efficient cities", which was launched by the German Federal Ministry of Education and Research and won by Stuttgart along with four other German cities (Delitzsch, Essen, Magdeburg and Wolfhagen) in September 2010, started the ball rolling and consolidated the courageous initiative "City with Energy Efficiency Stuttgart (SEE)". This project benefits from the longstanding experience of Fraunhofer IBP regarding energy retrofitting of existing and new buildings and even entire city districts. "The starting conditions for our research project were quite good", says the graduate engineer, "as we were joined by powerful partners right at the beginning, among them the Office for Environmental Protection of the state capital of Stuttgart, which has been closely collaborating with IBP's Department of Heat Technology for several decades". Besides, various institutes of the University of Stuttgart are taking part in this interdisciplinary project. Another powerful driving force is the energy company EnBW who made an important contribution by raising the efficiency of electricity generation by 20 percent due to installing back-pressure turbines in their power plants at Gaisburg and Münster. The scientific project is supported by extensive data material. For instance, comprehensive data supplied by the grid operators provide information on the volume of energy consumed in individual sectors, such as private households, industry and trades in the last few years. Besides, the data also reflect the share of renewable energy in the Stuttgart energy mix. Based on these energy data, the Fraunhofer researchers compiled an overall energy balance for the entire city in a two-year interval and visualized the energy flows. "The results of this analysis are surprising, as we found that industry and skilled trades have already remarkably improved efficiency in the last twenty years. Evidently, the compulsion to take action is very strong in these sectors, in order to be able to compete within the global market in times of rising energy prices. Compared to this development, private households are lagging behind. Particularly with regard to electricity consumption, the tendency of energy consumption is even increasing", Schrade declares.

"This is however not due to the classical energy guzzlers like combined refrigerator-freezers (as some may have suspected), but to newly added consumer electronics like tablets, rooters, or PCs". Another cause is the continuous rise in living space claimed by every inhabitant. Currently, the average living space used by a Stuttgart citizen is equal to almost 40 square metres, which is 5 m² more than the average amount of living space in 1990. "This additional living space needs to be heated, too. This development implies that the increasing need for space has almost completely neutralized the efficiency improvement achieved so far".

The next step is inevitable: all energy consuming sectors in Stuttgart need reassessment. This includes households, traffic, industry, trades, commerce and services as well as municipal properties. The citizens, too, are required to participate, because nothing will happen without their compliance. But how overcome the obstacle and convince people at the grass roots level? The scientist believes in "personal motivation". This means being present on site – showing up at forums, participating in panel discussions, in communal meetings and answering the citizens' questions. Sometimes choosing unusual paths and convincing the audience at owners' meetings, for instance. Schrade: "By directly addressing the citizens we can better understand their needs. Which questions are of concern to them and how can we convince people of our ideas without being obtrusive? Emotional aspects must not be underrated, either. Ever since the press has treated the topic of 'insulation mania' in a very populist way, citizens frequently tend to doubt the usefulness of thermal insulation. When examining the measures implemented so far, which were financed by the city's funding programme, it becomes evident that the negative coverage in the media has caused a decline in façade renovation projects. Our work experience has definitely taught us to take people's fears and reservations seriously".

To persuade the inhabitants of Stuttgart to actively take part in the energy turnaround, the scientists literally visit them in their living rooms. About 700 households in Stuttgart could take part in a household consultation. Besides recording the costs for electricity and heating, also the mobility behaviour, the equipment of the households with electric appliances and lamps and the state of the buildings were documented. Every participating household received a folder proposing customized energy saving measures, including information on potential savings and cost reduction. Scientifically, the data that were collected in the scope of the household survey are of great interest. Based on these data, it is possible to establish relations between a person's lifestyle and her/his energy consumption, which is unprecedented in this form.

Incidentally, the scientists of Schrade's team have even more ideas. For example, the team favours the idea not to expect people willing to refurbish their homes to have detailed knowledge of complex subjects; in the team's opinion, energy retrofitting measures should be initiated and implemented at the push of a button – so to say as an all-inclusive retrofitting service package. A service to assure the quality of structural measures would alleviate anxieties about botched-up construction work. Moreover, the team also addresses property managers who are often lacking competence in terms of refurbishment, offering support in the form of guidelines and calculation tools to estimate potential savings. An important task is allotted to independent experts, who do not represent economic interests. They are most trusted and could provide building owners willing to tackle refurbishment with advice and assistance. Johannes Schrade would like to send those proprietors who are still in doubt to stay for a test living experience in a retrofitted building, just to make them feel the difference in comfort. In general, wellbeing should be attributed much more importance, priority should not be given to strictly economic aspects. For example, when purchasing a car, the buyers focus not only on economic efficiency but also on choosing a vehicle (within the bounds of their financial possibilities) which makes them feel safe and well. So why not apply similar criteria when renovating a building, which has a much longer useful life than a car, and focus on improving comfort?

It is true that the turnaround of energy policy is a project for Germany as a whole, but it is implemented locally. Each and every one is required to contribute to help to achieve this goal. This is why Johannes Schrade underlines one point in particular: "The energy turnaround means so much more than just renewable energy and saving electricity. Many consumers look at their electricity bills and reduce the energy turnaround to the share of their EEG-allocation. Actually, the share of electricity in the energy consumption of private households does not exceed 10 percent. The key levers for saving energy are space heating and mobility, which account for 25 percent of the private energy consumption in Stuttgart".

Besides, the Swabian metropolis has been struggling against too high levels of ozone and too high concentrations of particulate matter for decades, only lately having been "elected" Germany's traffic jam city no. 1 ( Stau-Stadt Nr. 1). Though the problems may be enormous, yet there is a huge potential for improvement. In any case, Schrade's research team has already succeeded in convincing at least one important Stuttgart resident. In his political agenda, Lord Mayor Fritz Kuhn has integrated the scientific principles and the efficiency raising measures that were identified in the scope of the research project. By mid-2015, the municipal energy concept for an urbanisation of the turnaround in energy policy in Stuttgart will be published.


Forschung im Fokus
The monthly rubric gives insights into the research of Fraunhofer IBP.