The past few years, especially the last few months, have made one necessity extremely clear: We urgently and compellingly need to work on generating energy in a way that is as climate-neutral as possible, close to our locations - and as long as this is only partially successful, we need to conserve our resources. That this is not a new insight becomes clear at the latest when one takes a closer look at the matter. The approaches discussed and tried out are as diverse and imaginative as amorous entanglements in a daily soap, and they penetrate regions that are within everyone's reach. Floor coverings have long since ceased to be terra incognita when it comes to shedding light on their energy-saving potential.

Energy-saving properties of floor coverings come into focus

In fact, floor coverings can have a noticeable influence on how effectively heating heat remains in a room or how necessary air conditioning is in summer - and for how long. Two factors play a role here: firstly, of course, the thermal insulation, and secondly, the so-called foot warmth, i.e. a rather subjective impression, which, however, strongly contributes to whether one sets the heating one or two degrees higher in case of doubt.

Carpet is facing a renaissance because of its positive energy effects

Many manufacturers and suppliers of floor coverings have recognised this potential and, if available, emphasise the energy-saving properties of their products. Others are already going further and developing or optimising specifically in this direction. Okay, with the appropriate insulating layer on the underside, almost any type of floor covering can be optimised in terms of energy. Nevertheless, there are floor coverings that already exude warmth and comfort. Right at the forefront is an old acquaintance that has recently fallen somewhat behind in the general perception, but has long since deserved a renaissance due to its many positive properties - carpeting.

Carpeting can save up to ten percent on heating costs, according to Associated Weavers

Associated Weavers, for example, one of Europe's most important producers of tufted carpeting based in Ronse, Belgium, explicitly advertises the cosy comfort of its products. According to Associated Weavers, carpeting can save four to five percent on heating costs, and even up to ten percent in harsh winters. In this way, carpeting pays for itself in a short time. Moreover, no other floor covering brings as much warmth and atmosphere into the home as carpet.

One step further: The floor covering as an energy generator

Other suppliers and developers go a whole step further. Instead of saving energy, they even see the potential in floor coverings to generate energy. For example, researchers at ETH Zurich and Empa, a Swiss institute for the development of new materials and technologies: In their search for new building materials, they used chemical processes to modify wood in such a way that it is now able to function as a mini-generator. In other words, as soon as the wood is subjected to weight, an electrical voltage is generated.

The basis of this development is the so-called piezoelectric effect. It ensures that a piezoelectric material generates an electrical voltage as soon as it is elastically deformed. In fact, wood also has a natural piezoelectric effect, although only a very low electrical voltage is generated. To increase the yield, the researchers changed the chemical composition of the wood, making it more compressible.

Initial measurements on a piece of balsa wood treated in this way actually showed an 85-fold increase in electrical voltage compared to native wood. However, before the piezo wood can effectively be used as a biosensor or even as an electricity-generating parquet floor, there are still some steps to be taken, which will certainly consume more energy than it generates. Nevertheless, the Swiss researchers believe in their development and have already brought other cooperation partners on board to adapt the technology for industrial applications.

London-based company Pavegen uses floor tiles as generators

Pavegen, a company founded by Laurence Kemball-Cook in London in 2009, is a bit further ahead. His team is also pursuing the idea of converting pedestrian mobility into usable electricity. With around 5,000 steps that every person walks every day on average, there should be a huge potential for clean energy, they reasoned.

Instead of chemically modified wood, Laurence Kemball-Cook's team relies on electromagnetic induction generators. Three generators mounted under triangular tiles are shifted vertically by five millimetres each time they are stepped on, causing a rotary movement that in turn produces electricity. Each step provides around 1,500 revolutions per minute in the rotary gear, which is said to correspond to a nominal power of around five watts. This means that the current triangles, which are made of steel, recycled aluminium and a composite material, generate 200 times more energy than their forebears from 2009. In addition to the generators, each tile is also equipped with a wireless application-programming interface (API) that can connect to a range of mobile devices or building management systems in order to transmit real-time motion data analyses, for example.

Potential as a multifunctional flooring system in smart city projects

A memorandum of understanding already signed by Siemens and Pavegen is one of the indications that the system has potential and that we might soon encounter it as a multifunctional flooring system in smart city projects or at airports. The cooperation between the former start-up and the globally active Munich-based innovation company is intended to make the technology cheaper in the future and thus finally profitable.

Interesting links

www.carpetyourlife.com/de/wissenswertes/komfort-und-ambiente/bodenisolierung-durch-teppiche | https://youtu.be/R8KkMZPnF2U

ETH Zürich

Pavegen Systems Ltd. | https://youtu.be/bOJjlXfTJpI