The digital city: not just smart, but an urgent necessity

Why a district of Berlin will have a digital twin.

CO2-neutral cities are crucial for the achievement of our climate goals. Matthias Rebellius, member of the Siemens Managing Board and CEO of Smart Infrastructure, is convinced that the decarbonization of cities is impossible without the application of smart technologies. The example of Siemensstadt Square in Berlin shows how a digital city district can be created.


By Sarah Tietze-Kamya, Stefan Kögl, and Martin Tackenberg

At the moment, the Metaverse is the hot topic. The vision of Metaverse promises a new digital sphere, a virtual world that will fundamentally change the way we interact with our environment. Whether the Metaverse becomes the "Next Big Thing” or not: the digital world has long since found its way into our cities – especially when it comes to planning, operating, and using the underpinning infrastructure.


Cities play a central role in the fight against climate change. According to a new study by the Coalition for Urban Transition (CUT), "the battle for our planet will be won or lost in cities." This is because our cities are responsible for around three quarters of global technical related CO2-emissions, and the trend is rising dramatically.

Siemensstadt² Calling Podcast episode 11

Want more? – Check out the SiemensstadtCalling Podcast!

Matthias Rebellius, member of the Siemens Managing Board and CEO of Smart Infrastructure, was a guest on the SiemensstadtCalling Podcast. Listen to the episode in full length here and wherever there are podcasts. This episode is available only in German.


SiemensstadtCalling is a podcast for all those interested in urban technologies, urban development and smart buildings – and are eagerly awaiting the development of Siemensstadt Square.

But what does it mean to plan a city digitally? Where are the determining factors and how can smart technologies make our cities more sustainable? We asked these questions to someone who really knows his way around everything that is "smart" in facilities and systems. Matthias Rebellius, a member of the Siemens Managing Board and CEO of Smart Infrastructure.

Rethinking cities: not just smart, but an urgent necessity

For Matthias Rebellius there's no question: We need to rethink cities. For him, this is not just smart but an urgent necessity. It is clear to him that only through the use of smart technologies and a carbon neutral energy transformation can we make urban spaces more efficient in the future, and thus more environmentally friendly and liveable.


Rebellius identifies three crucial factors:

  • Less traffic through new mobility concepts, multimodal and intelligent traffic systems, and management.
  • Optimised energy generation through renewable energies and decentralised energy systems, which will manage the challenge of volatility on both sides, generation, and consumption.
  • Reduced energy consumption through intelligent energy grids and efficient energy use.

The interaction between efficient grids and smart buildings in a fully electrified world are key drivers in this development.

The digital twin 

For Rebellius, the smart city has long since ceased to be a vision but is now a daily reality in many places. The digital twin, for example, already comes very close to the metaverse. This technology enables the virtual replication of a real object, including its relevant properties and functions. It is updated in near real time as soon as the properties of the original change.


"The most efficient way is to build a building twice. You build it once digitally, simulate it and then optimise it. Then you build it properly", says Matthias Rebellius. This not only saves money, but also protects the environment, because as we know, the construction industry in particular consumes a large amount of energy and is the source of high CO2 emissions. And during its lifetime, a building, which is well designed by means of simulation with its digital twin, can again save a lot of energy and CO2.

The most efficient way is to build a building twice. You build it once digitally, simulate it and then optimise it. Then you build it properly.
Matthias Rebellius, a member of the Siemens Managing Board and CEO of Smart Infrastructure

Digital twins can also be used for the development and operation of entire cities and districts, such as Siemensstadt Square, by interconnecting buildings, transportation systems and other infrastructures, such as energy distribution, in a highly efficient manner, thus enabling sustainable operation of the district. This allows the city to be understood as an interconnected ecosystem and thus optimally operated. 

Solutions at the grid edge – the interface of distributed energy supply and demand with the electricity grid – play a crucial role in advancing the energy transformation towards a decentralized electric grid of a future city. The electrification of sectors, such as transport and heat generation, also create an important potential for a climate-friendly city. 


According to Matthias Rebellius, in the future it will be possible to digitally control an entire urban district like Siemensstadt Square. For example, residents will be offered seamless, modular public transportation or digital district concierge services. In smart buildings all HVAC systems and lighting systems will adapt to the real time occupancy and smart prediction – thanks to innovative technologies such as artificial intelligence.

Siemensstadt Square: digitally planned, digitally built, and digitally operated

Siemensstadt Square has been using the digital twin technology from day one. According to the motto "digitally planned, digitally built and digitally operated", the process of Building Information Modeling (BIM) is already being utilised during the planning phase: Digital models of all designs were required from the participants right from the architectural competitive tender phase. Now further developed, they form the basis of all planning, but can, for example, also be used to create vivid visualisations.

Smart technology is crucial to making a city CO2-neutral

It is particularly important for Matthias Rebellius that people understand what “smart” means and what benefits the smart city can offer its users. New environmental technologies, energy-efficient solutions and increasing digitalisation are not an end in themselves but rather intended to make all of our (urban) lives easier, safer, more liveable, and more inclusive.


Improving infrastructure and services by leveraging technology, information, and data can not only help to meet the challenges of our world, but they are also a simple necessity in a functioning urban community that wants to ensure a high standard of living for its population. In the end, it is not only the climate that benefits, but the whole urban society.

About the authors: Sarah Tietze-Kamya manages the communication around Siemensstadt Square and moderates the SiemensstadtCalling Podcast. Stefan Kögl is head of the Siemensstadt Square project and is implementing the new urban quartier with his team. Dr. Martin Tackenberg works at the Smart Infrastructure division at Siemens and deals with smart innovations every day.

Picture credits: Siemensstadt Square

December 13, 2021

Subscribe to our Newsletter

Stay up to date at all times: everything you need to know about electrification, automation, and digitalization.