Vibrations in the ground can provide clean energy

Vibrations in the ground exist everywhere. They occur when cars pass by, when machines are operating, or when the Earth’s crust moves. 

Instead of letting these small tremors disappear, researchers are investigating how they can be converted into electricity. 

This is done through technologies that respond to movement, bending, or pressure, and that are able to generate small but stable amounts of power.

“What makes the technology so exciting is that we can extract energy from movements that already exist around us. The vibrations are there anyway, and we can make them useful,” says Claudia Pavez-Orrego, a researcher at SINTEF.

She investigates where different vibration sources exist and how they vary. She also researches which technologies can best convert them into energy production. 

The goal is to develop solutions that can be used where only small amounts of power are needed, such as to power sensors.

How does this work in practice?

The basic principle behind vibration-powered energy is simple: movement can be converted into electricity. 

This happens mainly in two ways. One is through materials that create voltage when they are bent, stretched, or compressed.

The other is electromagnetic induction, which you are probably familiar with from your kitchen. Induction is the electric current that occurs when a magnet moves past a conductor. 

All types of conductors can be used, but copper wire is the most common because the material conducts electricity extremely well.

Both methods can convert continuous vibrations into small amounts of energy. Not much, but enough for sensors, measurement systems, and equipment that needs to function 24/7 without access to the power grid or frequent battery replacement.

We are becoming increasingly dependent on sensors

One of the biggest advantages of vibration-driven energy is that the source never runs out. In urban environments, small tremors are constantly created by traffic, construction work, and public transport.

In nature, geological movements create a continuous background noise that we do not notice. But technology can utilise it. Because vibrations are both widespread and stable, they become a highly accessible energy source that does not depend on weather.

Often, even small amounts of energy can be very valuable. 

Devices that harvest vibrations can power sensors. These can in turn monitor bridges, water systems, the environment, natural hazards, earthquake activity or water quality.

This can function even in areas where power grids and battery supplies are unrealistic.

From theory to reality

The work started by mapping different types of vibration sources. Researchers looked at both natural vibrations such as earthquakes and man-made vibrations from, for example, mining or traffic.

The researchers then developed digital models of devices that can capture vibrations. The team fine-tuned them by running extensive computer simulations.

Finally, prototypes were made and tested in a vibration rig in the lab. Here, the researchers were able to mimic vibrations as they actually occur in real life.

“Understanding how this technology works in the lab is one thing. Getting it to work in the field is something else entirely. Vibrations vary enormously between city centres, mountainous areas, industrial areas, and seismically active zones. That’s why we had to test the technology in different environments,” says researcher Nikolai Helth Gaukås.

Small amount of energy with great significance

Vibration harvesting is not intended to replace solar, wind, or hydropower. 

These established technologies are far more efficient wherever they can be used. But as a supplement, the use of vibration can play an important role in the green transition.

According to the researchers, the technology is particularly useful in places where solar, wind, and hydropower are not available. This could for example be deep inside mines, underground in CO₂ storage facilities, on the seabed, or inside closed structures.

The project is funded through the Global Research Council’s programme for the UN’s Sustainable Development Goals. It therefore also has a clear social mission.

"An important part of the work is to develop technology that can benefit low-income communities. Therefore, one of the basic principles of the project has been to make the technology as cost-effective as possible," says Pavez-Orrego.

“Our dream is to develop something that can improve the everyday life of residents in low-income communities,” she says.

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Read the Norwegian version of this article on forskning.no

This content is paid for and presented by SINTEF

This content is created by SINTEF's communication staff, who use this platform to communicate science and share results from research with the public. SINTEF is one of more than 80 owners of ScienceNorway.no. Read more here.

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