Top 5 applications for vibration energy harvesting
Where to use it & the most common applications
Introduction
Since founding ReVibe Energy in 2014, we have accumulated a lot of knowledge and experience when it comes to evaluating if vibration energy harvesting is the right way to go for the customer. And it is now time to share it with the rest of the world!
Without going into the nitty-gritty details, we look into the following X aspects when evaluating a potential new application:
1) Is the vibration continuous in terms of dominating frequency?
The first thing we evaluate is if we can determine a dominating and continuous frequency in the vibration where the acceleration levels are strong enough to generate a decent amount of output. For the wireless monitoring systems on the market today, the output from the harvester needs to be somewhere between 0,1 – 10 mA depending on the setup of the system in terms of sleep/active/transmission modes in the system.
2) Is it possible to use wires or batteries conveniently?
A key ingredient to even start evaluating vibration energy harvesting, and energy harvesting in general, is that wires or batteries are considered to be a problem and way too expensive to use. E.g. if a battery costs 10€ to purchase, runs out of power every 12 months and a battery replacement costs 100€ including labour, the Total Cost of Ownership amount to 310€ after 3 years usage. As an energy harvesting system is designed to compete with the cost of replacing batteries, a profit is available to be made for the user.
3) A strong need for monitoring
Perhaps this is sort of given, but it still remains an important aspect to mention. The need for monitoring needs to be big for the end-user to see the upside in investing in an autonomous (i.e. powered by a harvester) monitoring system. If there is money to make and save by using a monitoring system, an energy harvesting unit quickly makes a lot of sense as the cost of either installing/repairing cables or replacing batteries drives the maintenance cost up.
But without further ado, let us introduce the top 5 applications for vibration energy harvesting that meets the criteria above!
Top 5 applications for vibration energy harvesting
Railway
Railway applications ticks all the boxes! When a train is moving, there is constant vibration being created as a result through the friction between the wheel and the railway track. As a result, a continuous vibration is found and our energy harvesting units deliver steady output levels between 1 – 50 mA (3-5V)depending on the speed of the train. And, as you probably can imagine, it is not ideal to use batteries on the outside of trains as it would be very inconvenient to replace these batteries on a regular basis. As a final touch, it is easy to establish that railway companies would pay good money for the ability to be able to use predictive maintenance systems which would enable scheduled maintenance instead of emergency maintenance that normally incur large expenses.
Mining
Very similar to the railway industry from the perspective that each operator uses a lot of expensive and valuable equipment that normally is found in areas where it isn’t convenient to use either wires or batteries as a power source. Vibrations on the other hand are easy to come by as a lot of the equipment and machinery that is being used produces a steady and continuous vibration. Vibrating screens and crushers are excellent applications of such machinery! In these applications, vibrations are fairly strong and our units can deliver output levels between 1 – 50 mA (3-5V) depending on the vibration and the placement of the unit.
The Construction industry
The construction industry is quite similar to the mining industry but as construction sites often are found closer to cities and involves a larger number of people in a relatively small area, at least if we compare it to the mining industry. So replacing batteries is not as complicated, but could still be a big issue as construction companies of course want their staff focusing on core tasks rather than maintaining the maintenance systems.
And we have throughout the years found that there are a lot of different machines that are in dire need of monitoring! Among other, compaction machines and larger handheld equipment can be mentioned as examples.
Helicopters
An ideal application for vibration energy harvesting from which ReVibe has first hand experience. Our client was looking to install a monitoring systems in different locations in the helicopter where it was extremely painful to use batteries and it was completely out of the question to use batteries that needed to be replaced as it was considered to be a safety liability for the maintenance crew. Vibration energy harvesting was then considered as the ideal solution as vibrations from the helicopter were strong enough to power the entire system. Our units have in these environments produced an average output of 1 – 10 mA (3-5V) depending on their placement in the helicopter.
Rotating machinery / Bearings
A slightly different application where the use of vibration energy harvesting isn’t as widespread, yet. The reason for this is that vibration levels when the bearing is working without faults are fairly low and the output levels that we could generate in these applications are usually between 0,1 – 2 mA (3-5V) depending on the type of machinery. And now, when the Industrial IoT and Industry 4.0 has developed and matured a bit since a few years back, when the first concepts were seen on the market, this is a really solid application where vibration energy harvesting makes a lot of sense. Just imagine if your factory has 2000 assets that are being monitored constantly and you would have to replace the battery each 12 months. This would mean that one person would have to spend 520 hours replacing the batteries assuming 30 minutes per battery change. If hourly labour costs are 50 $, this means only the battery replacement would cost 26,000 $.
