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GrowSmarter study visit in Cologne: Smart City Cologne, deep building renovation, integrated mobility hubs & municipal data centre

Gabor Heves, Regional Environmental Center for Central and Eastern Europe (REC)
31 May 2017
GrowSmarter study visit in Cologne, Germany
GrowSmarter study visit in Cologne, Germany

Study visits comprise an important part of the mutual learning activities in the GrowSmarter lighthouse project, co-funded under Horizon 2020 programme of the European Union. On 27-28 April I participated in a visit in Cologne, Germany, which proved to be a very diverse, learning-rich and well-organised experience. The study tour gave us an excellent opportunity to learn about the practical experiences related to the implementation of smart cities measures of diffierent kind – building renovation, mobility, smart data, etc. 

Cologne– growing economy, growing challenges

The study visit was kicked off by a short introductory session, where the Deputy Mayor of Cologne, Mr. Harald Rau, gave the participants an overview of city’s current situation in areas such as environment, demography, economy and mobility. After that, Dr. Barbara Möhlendick and Mrs. Julia Egenolf, site managers for GrowSmarter, introduced concrete GrowSmarter measures to address the needs of the city. All in all, Cologne is an important economic and cultural center in Germany, which is currently facing a dynamic growth period: its economy is thriving and its population has just surpassed one million people. Therefore it faces large challenges in terms of increasing mobility problems, lack of qualified workforce or rising  energy use, to name just a few.

Smart Cities Cologne conference

In the evening the group joined the city’s annual smart cities conference, called “Köln mobil 2025 plus”. It was held as part of the Smart City Cologne programme, which by now has become a cornerstone for building a liveable, knowledge-based, and energy-efficient city. Just like Germany is already implementing a paradigm shift in the field of energy („Energiewende”), the event called for a similar shift also in mobility („Mobilitätswende”). The aim is a modal shift of 1/3 public transport, 1/3 walking and cycling and 1/3 private motorized traffic, plus a complete elimination of through-traffic in the city.

The introductory speech was delivered by Mrs. Henriette Reker, Chief Mayor, which demonstrates the high political commitment to positioning Cologne as a smart city.  The keynote speech was given by Mr. Sven Plöger, who is a TV weatherman. He gave a fascinating speech about the mechanisms and consequences of climate change. Average temperature increase has already exceeded 2 degrees in the arctic area, and he explained how the vast reduction in the size of the arctic icecap is resulting in the extreme weather events that we are facing more and more often now.

As part of a World Café session, participating citizens and various stakeholders could also provide input into further developing Cologne’s relevant policies and strategies.

In the evening, we could take part in a so called Hackathon. Young participants were encouraged to work out practical applications for low-budget environmental sensors.

Energy-efficient building retrofitting

After a long and exciting first day, we were ready to visit the GrowSmarter measure demonstration sites on the next day. First we went to Stegerwald Siedlung, which was Cologne’s first housing estate built after the war. Composed of four-level, brick-made buildings  and located in ample green space, it is a very pleasant environment to live in. Now, thanks to  the measures implemented as part of the GrowSmarter project it is becoming highly energy-efficient and innovative, too. All buildings are insulated and hooked up to the district heating, photovoltaics, heat pumps and battery storage are added, an energy-management system is launched, , smart meters are installed – just to name the most important energy measures. The original time frame for implementing all construction work was 5 years, however, due to the EU project’s requirements only 3 years are available for all construction work, requiring a very close cooperation between  all stakeholders involved (e.g. building managers, energy company, engineers, municipality etc.)

What are the main findings so far? Well, first of all, satisfying various administrative and legal regulations causes significant headaches. By nature, innovative measures challenge existing official requirements and permission processes, so unexpectedly much effort was put into this. Examples include fire regulations (e.g. construction of additional roof-firewalls after everything was completed), environmental regulations (e.g. it is forbidden to dig under treesbut the area is full of trees) or electricity regulations (e.g. you cannot feed PV electricity directly into tenants’ networks if they are not the owners  but physically they are the ones to use the power).

As a result of energy and other measures (e.g. adding elevators, adding one more floor, installing e-vehicle chargers etc.), flat rental fees did increase by 50%,  which in comparison still maintained Stegerwald’s position as the cheapest rent area in the city.

Study visit participants were also introduced to the city’s open data platform called Urban Cockpit. Just like an airplane’s cockpit, this platform allows gathering, visualising and analysing city data. Long discussions were devoted to the intricacies of data collection, and how to persuade various authorities to share their data.


The afternoon was devoted to smart mobility. Cologne is currently introducing full-scale articulated buses on one of its regular bus routes. We looked at one of these. It is equipped with pantographs, so that it can also charge quicklywhile waiting at the final stops.

An important outcome of the GrowSmarter project is the launch of the so called mobility points in busy locations of the city. We visited the first one - its information board has just been installed the day before! Its visual design aims to set the standard for the whole of Germany. A mobility station is a multimodal hub, including petrol-driven and electric car-sharing, (free-floating) city bikes, and an innovative app-based parking space rental scheme. Cologne is currently also in the phase of preparing an e-bike sharing system.

Computing centre

The study visit was completed by visiting the city’s computing centre. It covers mission-critical city services, such as hospitals, firefighters, municipal financial accounting, civil protection etc. The energy consumption of this high-end, high-security server park is rated at 800 kW. However, due to an optimised air conditioning system the cooling need was reduced to as low as 280 kW! Group participants were highly impressed by seeing the power distribution systems, the high-voltage UPS and power conditioning machines, the gas-based firefighting systems, and certainly the server-hall itself.

All in all, it has been an extremely enlightening study visit. Participants were very grateful to the organisers for their hospitality. This article’s length does not allow reporting all findings in details here, but if you would like to learn more, visit the City of Cologne’s website (in German), the GrowSmarter website or contact directly the Barbara Möhlendick (barbara.moehlendick@stadt‐ from the GrowSmarter team in Cologne.

Gabor Heves, an expert in the REC’s Smart Cities and Mobility topic area, has an MSc degree in Environmental Sciences and Policy (Central European University, 1997). At the REC he implements European research projects focusing on urban mobility, smart cities and research result communications. As part of the Smart Cities Information System (SCIS) initiative he is in charge of contributing to online content development and external outreach. In the EVIDENCE project (Economic Benefits of Sustainable Transport) he carried out a state-of-the-art review about the economic aspects of introducing Sustainable Urban Mobility Plans in Hungary. In the Clair-City project (Citizen-led Air Pollution Reduction in Cities) he analysed the role of citizens and NGOs in using GPS-assisted air pollution data. In the EU’s Energy Research Knowledge Platform (ERKC) he prepared thematic research analysis on topics such as photovoltaic.You can in touch with him on