Energy Harvesting – Intelligent Use of Ambient Energy

Ensuring a reliable and low-maintenance energy supply for small electronic systems is becoming increasingly important with growing digitalisation and connectivity. Energy harvesting – capturing energy from the surrounding environment for self-powered operation of small electrical consumers – offers a promising way forward here. By Sigrid Riewe-Scholz

Much of the energy around us goes unused every day. This is exactly where energy harvesting comes in. Even tiny amounts of energy generated, for example, by vibrations, temperature differences, or light can be captured and converted into electrical energy. For example, mechanical oscillations in machines or structures can be converted into electricity using specific materials. Likewise, temperature differences between warm pipes or radiators and a cooler environment can be used to generate energy. Light can also be a source of energy – even indoors.

The energy harvested is either used immediately or stored temporarily in small devices such as capacitors and micro-batteries. Sensors, radio modules and other small electrical consumers can then be run without the need for an external power source or battery changes.

What is particularly interesting is the use of energy harvesting in applications where conventional power sources fall short. In industry, for example, the technology enables continuous monitoring of machines through wireless sensors. And there is a growing range of applications in relation to buildings, such as battery-less switches and smart control systems. Energy harvesting is also playing a key role in the context of the Internet of Things (IoT), as numerous compact devices are required to run continuously with minimal maintenance.

However, the technology does have its limits. The amount of energy that can be harnessed is minimal, which means energy harvesting is mainly intended for powering small, energy-efficient devices. The availability of the energy source – such as constant vibrations or temperature differences – is also essential to reliable operation.

This gives rise to a range of possible applications. For example, the technology could be deployed for condition monitoring of tracks, points and other components. Sensors can continuously collect relevant data and give early warning of wear, damage and faults. This supports predictive maintenance and helps improve operational reliability.

Another possibility could be to implement redundant sensor systems that can increase the availability of critical information without requiring additional installation. Energy harvesting could play a role, for example through self-powered position sensors that enable local detection of vehicles or equipment and thereby facilitate more efficient process control.

Conclusion

Energy harvesting could deliver added value in the area of trams and light-rail vehicles. The combination of self-powered sensors, minimal installation effort and long-term maintenance-free operation would enable intelligent, networked and robust monitoring of technical systems. The technology could thereby make an important contribution to the modernisation and digitalisation of public transport.