Changing conditions

It’s an ingenious idea to solve several problems at once: fields of plants sit protected from heavy rain, hail, drought and the desiccating sun under large sheets. But this is no simple plastic sheeting: the thin, high-grade film is full of transparent organic solar cells (pictured). These films allow the visible light through that the plants need to grow but use the infrared part of the spectrum to generate electricity, providing another income source for farmers. Or they use the energy themselves to distribute the water they collect to the individual plants according to their exact needs; after all, water will be an even more valuable commodity in the future and not something to spray around indiscriminately. 

What might sound like science fiction is already reality at the Fraunhofer Institute for Solar Energy Systems ISE in Freiburg Or at least a research reality. Teams there have been working on agrivoltaics – using land for both solar power and agriculture – for some time now. Their projects are researching how agriculture can adapt to our changing climate with the help of such innovative technologies. “Agrivoltaics won’t stop the climate from warming, but it will help us to adjust to this change,” says Max Trommsdorff, head of the ISE agrivoltaics team. 

Not so long ago, such solutions would have been regarded with distrust, as treating the symptoms of climate change rather than the disease. Of course, it would have been much cleverer to tackle the causes of man-made global warming earlier and more resolutely to avoid the need for climate adaptation in the first place. But closing our eyes now to the fact that climate change is here and irreversible would not be particularly clever either. The last few years have seen too many heat waves, once-in-a-century floods and other extreme weather events for that. 

Along with tackling worsening global warming, climate adaptation is a priority for the whole German government and particularly the Green Party’s Steffi Lemke, the Environment Minister. She plans to present a new adaptation strategy by the middle of the legislative period to finally replace the old one from 2008. The strategy will be based on the Climate Impact and Risk Assessment presented by the German Environment Agency last year. “And it will doubtless be considerably more ambitious with clearly measurable targets,” promises meteorologist Petra Mahrenholz, who has been leading the “KomPass” center of expertise within the Environment Agency since it was founded in 2006. Specializing in climate impacts and adaptation, its role is to promote the adaptation strategy and help enhance it further. In our conversation, she emphasizes her view that climate adaptation is a challenge for the whole of society that must be tackled across all sectors. This includes electrical engineering and information technology, for example when it comes to making cities more heat-resistant to help them cope with rising temperatures: “A lot needs to happen in heating and climate-control technologies alone and preferably in a way that consumes less energy rather than more,” says Mahrenholz. After all, the Intergovernmental Panel on Climate Change (IPCC) holds urban areas responsible for over 70 percent of CO2 emissions and up to 76 percent of energy consumption. Installing even more conventional air-conditioning systems to cool buildings down might help us adapt to the new climate, but it would speed up global warming even further. “That can’t be allowed to happen, of course,” says Mahrenholz. “We need to urgently pursue both goals and can’t let them contradict each other.” 

In any case, the focus of climate adaptation is not just on farming and forestry but cities, too. “A smart city today must also be a climate-resilient city,” says engineer Jens Hasse from the German Institute of Urban Affairs. Since the beginning of the year, he has also headed the climate change mitigation center set up a year ago by the Federal Government to advise municipalities. For Hasse, putting climate adaptation on the agenda is a prerequisite for any smart city – not just because it is the only smart thing to do, but because digital solutions simply lend themselves to this topic. 

A good example is the sponge city. The principle of the sponge city and water-sensitive urban development takes a holistic approach, offering solutions for both ends of the climate extreme – heavy rain and heat waves or drought. The aim is for a city to absorb excess water, hold it like a sponge and then release it slowly through evaporation and targeted irrigation. The advantages of a sponge city are varied: as well as protecting against the impacts of heavy rain and cooling the city down in hot weather, it also reduces irrigation costs and boosts biodiversity by creating new green spaces. But such designs would not be possible without digital solutions. “A blue-green roof is equipped with a sensor system and responds actively to the current weather situation and forecast,” says Hasse, explaining the idea behind these smart roofs. That means it can automatically store water or release it systematically. 

Of course, designing cities that can better cope with the climatic conditions of the future is primarily a task for architects and city planners. They have to learn that it is not a good idea to build glass palaces that inevitably overheat in the summer. There are many lessons from what, at least in the past, was common practice in more southerly climes: buildings constructed close together to provide shade, climate-adapted building materials and methods, and passive ventilation measures rather than power-hungry air conditioners.  

“From solar cooling to integrated control systems and building-integrated photovoltaics, there is still plenty to do for electrical engineers, too,” says Hasse. He adds, though, that this is often not so much about new innovation as implementing solutions at scale that have already been developed for several years. Like Hasse, Mahrenholz also sees the need for development, research and, above all, debate in a completely different area: “We need to think urgently about how we will make our infrastructure resilient to disruption from extreme weather events,” she says. Looking back at recent disasters such as the flooding in Germany’s Ahr Valley in 2021, Hasse adds, “At the very least, we have to make sure we really are wiser after the event.” 

There is plenty to do here, as VDE’s ITG and ETG societies repeatedly emphasize. Energy for example: interruptions in the power supply via distribution and transmission grids are a source of potential supply restrictions. They can occur when grid infrastructure is damaged by heavy rain, floods or storms. But even heat and drought can also become a problem. High temperatures reduce the transmission capacity of power lines, while dry soils can trap heat dispersing from underground cables, also disrupting energy distribution. Communications technology can be hit, too. An outage at even just one data center can cut phone and Internet connections to whole regions – as happened in the Elbe flood in 2013 – or, as in the recent heat wave in London, can even take websites offline all around the world. “If we want to adapt to the climate, we can’t do so without a resilient power and communications infrastructure,” says VDE CEO Ansgar Hinz. “Energy supply and communications are mutually dependent, and that means targeted, cross-sectoral efforts and solutions are essential along with a coordinated approach and clever regulation. VDE is ready for this.”