Energy | 29. November 2010 | posted by Jan Oliver Löfken

Energy question of the week: How can urban areas efficiently save energy?

Germany is a country of towns and cities. Almost 90 percent of the population lives and works in urban conurbations – from Aachen to Görlitz, from Flensburg to Friedrichshafen. The need for energy is obviously highest where these people are located, and that is the key to achieving a reduction in carbon dioxide emissions. However, what form should intelligent urban redevelopment take, from transport through residential accommodation to workplaces?

"All German towns and cities have great potential for saving energy," states Hermann-Josef Wagner, Professor of Energy Systems and the Energy Economics at Ruhr University Bochum. The possibilities range from efficient thermal insulation in old buildings to ingenious traffic management and also extend to low-energy lighting of public spaces. Numerous technologies are already available, but their introduction often fails due to high costs, multiple conflicting interests or the ponderous decision-making processes in local bureaucracies.

New ideas through a national competition

The 'Energy-efficient Town' competition, initiated by the German Federal Ministry of Education and Research (Bundesministerium für Bildung und Forschung; BMBF) has created some momentum in this hesitant development and could deliver financially viable conversion concepts for the entire country. Seventy-two municipalities, ranging from million-inhabitant cities to the small towns in the country have responded to the call to develop intelligent and practical energy plans. Of the 72 respondents, 15 qualified for a 200,000 Euro grant to enable them to prepare their redevelopment strategies. In autumn 2010, this list was reduced to five winning towns and cities. These are Essen, Magdeburg, Stuttgart, Wolfhagen, in North Hessen, and Delitzsch, in Saxony.

Städte aus dem All. Bild: NASA/DLR

Urban areas at night. Credit: NASA/DLR.

"Local authorities must understand their cities as complex systems," says Michael Knoll at the Institute for Future Studies and Technology Assessment (Institut für Zukunftsstudien und Technologiebewertung; IZT) in Berlin. In addition, transparency and public discussion help to achieve widespread acceptance, ensuring that the plans they devise gain the support of their citizens. This rationale prompted the overall winner, the city of Essen, to place its inhabitants firmly at the heart of the climate initiative that it adopted.

Energy from waste

Magdeburg aims to transform itself into an urban role model for renewable energy. An 'Energy Geo-Information System' with the use of refuse and renewable fuels in power stations aims to achieve a 40 percent reduction in the emission of greenhouse gases by 2020, compared to 1990 levels. Stuttgart is setting itself similar targets, and it intends to draw up an 'Energy Roadmap for 2050'. Delitzsch is also giving careful consideration to the socio-economic aspects of its urban environment and intends to adapt its infrastructure strategy to reflect the downsizing affecting this medium-sized town.

It is important that the ideas tabled by the 15 finalists do not disappear into the archive drawers of the planners. Aachen could become a example for many historical towns and cities to emulate. The focal point here is the energy-conscious way in which listed buildings are being renovated. Using affordable methods, historical buildings are fitted with more efficient thermal insulation that does not affect their external appearance. Munich intends to promote the bicycle as an energy-efficient means of transport for a cleaner future.

Wolfhagen aims to get all its energy from renewable sources

Wolfhagen, the winner in the Small Towns category, set itself an even greater challenge, despite having a population of barely 14,000. It intends to cover its entire future energy needs from renewable sources. This target will be achieved by renovating buildings, fitting solar panels, building a 'citizen's wind farm' and using biomass-fuelled power stations. An intelligent power grid will balance out supply and demand, and lay the groundwork for a larger fleet of electrically powered vehicles. "A great many municipalities could benefit from these solutions, and from a better understanding of the difficulties involved," says the coordinator of the Wolfhagen plan, Christina Sager from the Fraunhofer Institute for Building Physics (Institut für Bauphysik; IBP).

The five winners will be able to implement their concepts over the next three to five years – with financial support of up to one million Euro per year. The German Federal Minister of Education and Research, Annette Schavan, is hoping that all the other participants can still derive benefit from the competition and that "new concepts and research results can be incorporated into urban planning".

The DLR Energy question of the week in 'The future of energy' Year of Science

The Federal Ministry of Education and Research (BMBF) has given the Year of Science 2010 the motto 'The future of energy'. For this reason the science journalist Jan Oliver Löfken will this year answer a question on the subject of energy in his blog each week. Do you have a question about how our energy supply might look in the future? Or do you want to know, for example, how a wave power plant works and how it can efficiently generate electricity? Then send us your question by email. Science journalist Jan Oliver Löfken will investigate the answers and publish them each week in this blog.



About the author

Energy journalist Jan Oliver Löfken writes among other things, for the Technologie Review, Wissenschaft aktuell, Tagesspiegel, Berliner Zeitung and P.M. Magazin on issues involving energy research and industry. For DLR, he answered the Energy question of the week during the Year of Energy 2010. to authorpage