IoT Hacks #1: Energy harvesting for low-power embedded systems – Blog Solwit

IoT Hacks #1: Energy harvesting for low-power embedded systems

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Written by: Piotr Strzałkowski, Embedded Domain Expert

With this post, we are starting IoT Hacks – a series of articles that covers the use of cutting-edge embedded solutions for IoT across various industries. We will even show you how you can revolutionise your existing IoT solution. Better yet? In some cases – this can actually be accomplished in just a few simple steps. How’s that possible? That’s what you’ll find out from this article. Keep on reading and get inspired.

What is energy harvesting?

So, what’s on the table today? “Energy harvesting,” it is. Or, to be more precise, extracting it from other sources when your device has limitations.  “Energy harvesting” (also known as power harvesting or energy scavenging) covers various types of ways to process energy from our surroundings.

What are the types of energy harvesting? As it turns out, energy can be obtained from:

  • light

  • vibrations

  • temperature differences

  • magnetic fields

  • radio waves.

There are pros and cons to each of these options. In addition to this, keep in mind that some of these solutions might not work for all cases.

Solar Energy - the most efficient energy source for powering IoT devices

As the table below indicates, solar panels generate the most energy per cm² of surface area, of all the methods of generating energy. But – harvesting solar energy will work best with systems placed outside the building, as only then will they perform most efficiently.  As you could probably guess, the efficiency of such systems is lower indoors and requires the units to be placed close to windows or in the vicinity of lamps.

So, having exposed this, let’s look into the next option of harvesting energy.

Drawing power from the temperature difference

To boost the performance of solar panels, consider “thermoelectric energy harvesting”. It means energy harvesting through temperature differences, utilising a TEG (Thermoelectric Generator).

In a nutshell, TEG technology is all about how a cell that is heated on one side and cooled on the other, produces an electric current. The greater the temperature difference between the cell’s covers, the greater the voltage and current that such a cell can produce.

So, here’s what we need to keep in mind: any temperature difference between the environment and an object that is cold or warm can, therefore, generate ecological energy.

Radio waves to generate energy

Another interesting find to consider. Let’s take a dive into radiofrequency energy harvesting.

This option will come in handy in office spaces with a high amount of WIFI and GSM equipment. That way, energy can be harvested at a high and ongoing level. Specifically designed and integrated into the IoT device antennas gather energy from the radio waves and help power the system.

Powered by vibrations

Last but not least, is the use of vibration for energy generation (vibration energy harvesting). In this case, energy can be produced by piezoelectric crystals (similarly to how an automatic lighter works) or other elements that generate electromagnetic fields. Such solutions are already applied in watches, shoes (with elements placed in the soles), or children’s scooters.

Summing it up

So, for now we’ve briefly covered energy harvesting methods that can support a power system for IoT-equipped devices (energy harvesting devices). Especially those that have, up until now, been primarily battery-powered. Thanks to this, the life of a device on battery power can be significantly extended. Alternatively, battery power can be completely replaced by another, less obvious method.

If you are wondering whether it is possible to extend the battery life of your IoT device, or you are looking for a technology partner to create dedicated IoT solutions – get in touch with us!

 

We have delivered many projects that required energy harvesting with great success and we will be more than happy to tell you how this can be done. Drop us a line to arrange a free consultation!

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