Energy harvesting

What does the term energy harvesting really entail? There’s a lot of different views and opinions on the subject. We have, of course, gathered everything and as experts within the subject, we’ll provide you with our view on the matter.

Lean back, relax and we hope you enjoy the reading!

The concept of energy harvesting

Energy harvesting (also known as power harvesting and energy scavenging) is sourced from an external source (e.g. solar power, wind energy, vibrations, etc.) and stored with the purpose of powering small, often autonomous and wireless, devices. In simple terms: different concepts of energy harvesting is sourcing energy from different process where the energy being sourced was previously lost and not utilised. Now, the surplus energy is being put to use.

From what sources can energy be harvested?

Energy is available all around us in different forms and shapes. Everything from the sun to the wind gusts and the waves contains a massive amount of energy. So does the vibration we feel in industrial environments, the heat differences from piping as well as radio frequencies transmitted by all connected devices around us. Simply put, energy is all around us. But to make it a bit more structured, the different sources can be explained as follows:

Vibration energy harvesting

Vibrations can be harvested by, mainly, two different technologies: Electromagnetic induction piezoelectronics.

Electromagnetic induction uses the concept of a magnet (or magnetic material) that is being pushed through or outside a copper coil in order to induce a current into the coil that can later be converted into electricity. Generally speaking, electromagnetic harvesters are bigger then piezoelectric harvesters but has on the other hand the possibility of producing a lot higher output (1 – 500 mW of continuous output for ReVibe’s products).

Piezo harvesting uses the piezoelectric effect that is created when certain materials are being deformed/put under pressure and an electric charge is accumulated. This technology is utilised in many industrial application where low-power electronics are being used, e.g. tyre pressure monitoring.

For more details around vibration energy harvesting, please visit our article around the topic (clink the link).

Thermal energy harvesting

Simply put, thermal energy harvesting is all about capturing heat which is either freely available in the surroundings are heat that is considered waste, usually coming from engines or similar sources that normally uses the heat.

To be a bit more specific, it’s actually the heat difference in and not only the heat that is harvested. This is done by relying on a special type of semiconductors, that is known as thermoelectric materials, that creates electricity when the thermal energy moves through the thermoelectric material from the hotter to the colder side. You can also find more details on the topic here

Examples of thermal energy harvesting and more information around them can be found here (link) and here (link).

Wind power / wind harvesting

There are multiple ways on how to harvest wind energy. To be able to give you the best overview of different alternatives we’ve decided to refer to the following sources of great information: CTM Magnetics – How to harvest and store wind energy, Wind Energy Basics and our beloved friends at Wikipedia

Why is energy harvesting a big deal?

If the user chooses the right type of energy harvesting based on the surroundings, energy harvesting can offer a sustainable (both economically and environmentally) power source for most wireless sensor on the market today. Most likely, energy harvesting will give you the opportunity to increase data rates compared to batteries. And it will definitely provide you with the opportunity of placing wireless sensing systems in locations where it hasn’t been possible to place them in the past due to the fact that maintenance crews needs to be able to reach them to replace batteries or install the cable. 

So in the best scenario, you will be able to increase the data rate of your system whilst lowering the Total Lifetime Cost of the system as you will not have to spend time on replacing batteries throughout the entire lifetime of the system. And, by placing systems in previously unreachable locations you can access information and develop new business models and revenue streams that you haven’t been able to develop earlier.