“Smart means thinking ahead”

Does a smart city these days necessarily have to be a climate-resilient city? 

Jens Hasse: I think that’s essential. “Smart” isn’t just about digital technology; it means being clever and doing things intelligently – in this case, thinking ahead about climatic change and extreme weather events that could affect the city in the future. But even the technical and digital aspects of the smart city often touch on climate resilience. 

In what way? 

Hasse: Digital solutions aren’t just useful for improving streetlights or the energy supply. If we have this technology and infrastructure in place, we can also use it for other services such as climate change mitigation. For example, if you already have a sensor used for managing parking space, you can add to its functionality or at least use the same cables for measuring local weather and climate data. Precise local data coupled to accurate forecasts can be very important in responding to extreme weather events. 

To avert flooding disasters, for example. 

Hasse: Precisely. We’ve now learned that just channeling rainwater away is not a good solution. We saw this in the Ahr Valley in 2021 but we’ve also seen it in towns and cities like Goslar in 2017 – the runoff water builds up higher and higher and faster and faster until it’s impossible to capture or divert it anymore. So we need smart systems everywhere in the catchment areas of rivers and streams but also in residential areas on higher ground to quickly and intelligently recognize what water can be channeled in which direction and where it can be stored. Reservoirs and retention basins can then be emptied in a controlled way, for example, so that they can collect more water in such scenarios. Smart roofs can also play a role here. 

What’s smart about these roofs? 

Hasse: The “blue-green” roofs – green roofs that can also hold rainwater – are fitted with a sensor system and connected to the network for the whole neighborhood. They can be managed automatically or even actively according to the current weather situation and forecast. That means they can store excess rainwater and protect buildings and whole districts from the impacts of very heavy rainfall events. And they can also protect from heat and drought by providing water for cooling and for irrigating plants and trees. What’s more, all this is largely automated, so it doesn’t need people to plan and manage it anymore. All these solutions exist already, for example in agriculture or in smart gardening. But, of course, it involves a degree of investment on the part of building owners and municipalities or their drainage services, which partly explains the hesitancy about such technological solutions. 

You just mentioned the heat. What other innovations are conceivable in this regard? 

Hasse: You could, of course, use a sensor system like this to warn people to seek out certain places or avoid them or to tell people where they can go to cool down. It’s not just science fiction: interactive heat street maps already exist in cities like Paris as well as in Worms and various other communities in Germany.  

Cooling devices are climate killers, aren’t they? 

Hasse: It’s worse than that. Most air-conditioning systems don’t just make the air inside buildings cooler; they also make the air outside hotter. That’s because they release all the hot air onto the street – a public space. Going forward, we need to design buildings very differently and use the laws of physics – that means doing a lot more with shade, chimney effects, other construction materials etc. 

Not so much a field for electrical engineers then? 

Hasse: There’s plenty to do for all kinds of engineers – from solar cooling to integrated control systems and building-integrated photovoltaics. Often, you don’t have to reinvent the wheel but just consistently implement the sustainable construction approaches we’ve been talking about for years. We can’t leave everything here to architects and clients; for them, the architectural design and the cost are the key criteria. The aesthetics can’t take so much precedence in the future if we want to build in a climate-resilient and resource-efficient way, and concern about the costs is often too short-sighted, since sustainable solutions always pay off in the long run over the whole life cycle. 

Does a smart city need to protect its infrastructure better? 

Hasse: Definitely. Of course, we have to learn the lessons of flooding disasters like last year’s and recognize that it certainly wasn’t a good idea for the hospital in Eschweiler to put the operating theaters two floors underground without robust flood-proofing like you see in Hamburg, for example. At the very least, we have to make sure we really are wiser after the event. That means smart cities should also include climate change mitigation and other protections that factor extreme weather events into city planning – building electrical distribution cabinets a meter above ground level, for example, or putting heating and ICT systems in the roof rather than the basement. 

That sounds simple enough. 

Hasse: In many cases, it really is. Some measures may need to be more fundamental, however. Smart power grids, buildings that generate their own electricity and emergency battery systems are some examples of how we could make individual neighborhoods and communication systems more autonomous and secure in the event of a flood or other major incident. But implementing something like that is not just about technical solutions but also responsibilities, legal frameworks, funding, good communication and preparedness etc. And arranging all that is not quite so easy.