At Hanover Fair I met Dr. Michael Weinhold, chief technology officer of Siemens Energy. Here are his thoughts on how to make cities more energy-efficient.

 

 

 

 

Dr. Weinhold, what are the biggest levers to increase the energy efficiency of our cities?

Michael Weinhold: In addition to integrated transport systems and industrial plants, which, for example, could use more variable speed drives, I see building insulation as one of the most important points. And of course a highly efficient power generation in central power plants or combined production of electricity and heat. But in case of CHP the electric efficiency must be higher than about 40 percent in order to have sufficient fuel efficiency. Unfortunately the electric and thermal efficiency are often just added up which is not correct. Electrical energy is much more valuable than thermal energy!

Editor's note: Dr. Michael Weinhold is an employee of Siemens Energy. Siemens is a sponsor of The Energy Collective.

But Siemens doesn’t make money out of improved building insulation…

Weinhold: Sure we do! Because the insulation is the key to the use of electricity from our highly efficient, flexible power plants. And of course from our renewable wind and solar power plants. For a very well-insulated building, for example, low-temperature heat is sufficient, which can be produced efficiently using an electrical heating system. Generally, electrical power more and more becomes the determining form of energy in our everyday lives.

 Even in heat production?

Weinhold: The combined production of electricity and heat is very beneficial. But in this process especially the power generation has to be highly efficient as mentioned before. Electrical energy is the energy of the highest quality. If you, for example, use a heat pump, it is possible to gain three to five times the amount of thermal energy from electrical energy. There are already many new housing districts in Germany where no more gas lines are installed, but the heat is completely covered by power.

Can you quantify potential benefits from these efficiency initiatives? 

Weinhold: In recent years we have studied in considerable detail how 30 European cities can increase their potential for greater efficiency and reduce their CO2 emissions. For the Bavarian city of Munich, for example, we have calculated that up to the 900-year anniversary of the city in 2058 an emission reduction by over 80 percent is possible.

How important is the end consumer in your planning?

Weinhold: We live in a time of transformation, not only in energy supply, but also in telecommunications and IT. We are developing so-called Smart Grids. We technicians often have very complex ideas in the already complex field of power generation and consumption. To take the end user - who has to accept and support these processes - along with us on this journey, we have to simplifying. Engineers must now communicate very well and very much to be understood right. We also need to listen exactly to younger people how they want to live. I have observed, for example, that many youngsters are much more than previous generations willing to live without their own car and to use integrated transport systems instead.