There are also good guys and bad guys in construction. Wood, for example, is one of the environmentally friendly building materials. Concrete is considered a bad guy. Above all, cement, which combines with water and aggregates such as sand or gravel to form concrete, is a climate killer. The consumption of concrete has multiplied worldwide. The material can hardly be dispensed with – for example in bridge construction. Office buildings and hospitals are also often built with it. This has economic, sometimes constructive, sometimes just lazy thinking reasons, at least the world is finding it difficult to do without concrete as an addictive substance in modern construction.
This has consequences for the environment. More than four and a half billion tons of cement are consumed worldwide every year. Its energy-intensive production leads to enormous CO₂ emissions. The concrete industry is working feverishly on alternative processes and formulations. For the time being, however, Bonnie and Clyde are still called Concrete and Cement at the construction site. Although the material, characteristic of an era of dizzyingly built boldness, is time-honored. Even the Romans knew concrete.
Now there is hope that cement, of all things, is being celebrated as the superhero of energy policy. On the technician platform engineer.de it says: “Are foundations, roads and walls becoming electricity storage?” Behind this is a message from the Massachusetts Institute of Technology (MIT) in the USA. According to this, American researchers are working on a supercapacitor that uses soot, water and cement to store energy.
One of the challenges on the way to a climate-neutral future is the storage of wind and solar energy. Because energy is also needed when the sun is not shining and there is no wind. According to MIT, cement and soot in particular could be used for a revolutionary storage medium because under certain circumstances these substances combine to form a composite with highly compressed conductive surface structures. The method is described in an article in the journal PNAS.
While today’s battery technology is expensive and reliant on limited resources such as lithium, active-like capacitors can use the widely available and comparatively cheap cement. “The material is fascinating,” says Professor Admir Masic, who researches sustainable building materials of the future at MIT. A house that is erected on a suitably enriched concrete base could generate electricity on the roof via photovoltaics, which is then stored in the building mass and then released again as required. Theoretically.
Concrete roads powered by roadside solar panels are also conceivable, in order to pass the energy on to electric vehicles – as with wirelessly rechargeable smartphones. Even if that’s a dream of the future: The bad guy cement, the production of which should be more climate-sensitive, might end up being one of the good guys.