Innovation and technology remain our last hope in finding an answer to our ever worsening energy woes. Alarm bells have been raised for many decades now about how we can’t continue to rely on fossil fuels, which are depleting at a historically unprecedented rate.
Many breakthroughs have been made to tackle this problem. Being a company invested in all things energy harvesting, we have covered this topic at length in our editorial pieces. If you’re new to the topic of energy harvesting, the premise is very simple - we lose enormous amounts of energy to losses and dissipation - what if we could find a way to capture and store some of this energy that’s abundantly available all around us?
The most elegant part about all this is that using this energy doesn’t only have ZERO impact on our overall energy usage, but also makes it possible for us to integrate low-power sensors and IoT devices into products, without losing sleep on finding ways to power them - it’s a total win win!
Automobiles are an obvious contender when it comes to rich sources of hitherto untapped energy - automobiles lose a lot of energy to their surroundings in terms of heat, vibrations and mechanical losses. Harvesting energy from moving vehicles has been an area of tremendous promise for quite some time now.
In an earlier post, we’d discussed how recent breakthroughs have made it possible to capture energy that is wasted through an automobile’s suspension system and use it to power in-built sensors and add ons. This is just the tip of what is understood to be quite a massive iceberg. We are now at a stage where energy harvesting is still quite a recent technological phenomenon and the core ideas, tools and pathways are being laid down.
This may be why you won’t see energy harvesting technologies powering your homes just yet. But that’s how any landmark technological advancement works - it takes time for the groundwork to be done and the allied technologies to come together. The pathway to making a commercially viable design from a laboratory prototype isn’t always a straightforward one and might make things seem disproportionately resource draining in the early stages.
However, the rubicon has well and truly been crossed with energy harvesting. The rise of IoT devices and connected networks has irreversibly ensured that energy harvesting isn’t just a passing fad - it’s most certainly a technology that’s here to stay.
It is estimated that there are over 1 billion cars currently on the road all over the globe. Add to this the number of cars that are being manufactured and sold all over the world as you read this and the number becomes quite astronomical. This is just cars - what about trucks, buses, heavy-duty industrial vehicles and so on? All of these vehicles, provided they use internal combustion engines, have one thing in common - they produce a lot of heat that is essentially lost to their surroundings.
It isn’t all that difficult to understand why we’d want to capitalise on this wasted energy and find a way to put it to good use - after all, we don’t have a lot of energy going around. And the energy that we do have access to, comes at a terrifying environmental cost. It was only going to be a matter of time before we found a way to put two and two together.
There are a number of ways in which we are already able to harvest thermal and vibrational energy efficiently. If there’s one place where there’s an abundance of heat and vibrations, often annoyingly so, it’s on a motorcycle. Ask anyone who’s thrown a leg over a capable two wheeled monster, and they’d tell you that although they can be a blast to ride, the heat can be a real bummer.
The bigger and faster a motorcycle, usually, the more heat that they emit. If you’ve ever wondered why leather is such a universal choice for motorcycling attire, there you have it - cooked thighs are a very real and very painful reality of riding high-capacity motorcycles. Add vibrations from the chassis and the exposed parts, and you have a perfect recipe for a potential energy harvesting solution.
Motorcycles are a heretofore unexplored platform that boast of some pretty incredible characteristics in terms of energy harvesting potential. This is mainly due to the fact that motorcycle exhaust systems are exposed to vast quantities of air flow.
Thermoelectric energy harvesting is pretty straightforward - it is based on a phenomenon called the Seebeck effect, and in essence, involves generating usable amounts of energy from a temperature gradient.
So, what do we have here? We have a fairly ubiquitous piece of machinery that is used all around the world. Check. These machines are known for the sometimes intolerable amounts of heat they put out. Check. Now add to this the fact that the mechanical components of a motorcycle are exposed to the elements - the large amounts of airflow hitting the engine parts and the silencers - you have the final ingredient to successfully harvest thermoelectric energy. Huge temperature gradient - check!
All the way back in 2008, a team of researchers led by Alexander Schlichting published a paper documenting their experiment conducted on a 1995 Kawasaki Ninja 250R. They used a Melcor HT3-12-30 module which produced an average of 0.4694 W from a temperature gradient that, on average, hovered around the 50°C mark.
The initial idea was to entirely eliminate the battery pack or alternator on a standard motorcycle and make it entirely self-sufficient for it’s electricity needs - This experiment didn’t quite produce the sort of power output that would enable the battery pack to be dispensed with. But let’s not forget that this was all the way back in 2008, when energy harvesting was all but a pipe dream.
Today, we live in an entirely different landscape. The internet of things has changed the rules of the game, as it were. Today, we not only have more capable and more efficient thermoelectric generators (TEGs), but also a much more robust understanding of where energy harvesting can be best utilised.
Let’s take a look at a more recent study conducted by Omar et al in 2019. Published in the Journal of Electronic Materials, this paper documents the team’s attempt to harvest significant amounts of electricity from a motorcycle using modern TEGs.
The study, conducted on a single cylinder Honda EX5 Dream (adorably nicknamed “Kapcai” in motorcycling circles), demonstrated just how far we’ve come in a little over a decade. The study was aimed at studying just how effective it is to install TEGs in the underbelly of a motorcycle’s chassis. The bike’s cooling system was used to remove heat from the cold side of the generator, thereby establishing the all important temperature gradient. The team made use of two commercially available TEG units.
The team recorded a maximum power output of 4.2 V! Now that’s definitely something right?
This was from a humble 100cc commuter bike - think about how this scales up with litre-class superbikes which are all but the norm in developed markets. Today, we understand how to utlise these seemingly marginal energy gains effectively. Motorcycles today are chock full of sensors and electronic wizardry - ABS, lean angle sensors, traction control, fuel sensors and the list goes on - These integrated smart systems are fast becoming an indispensable part of motorcycling. Using TEGs to make these IoT systems energy independent is by no means an unrealistic proposition today. In fact, in just a few years, they are very likely to make their way into the motorcycling mainstream.
Heat is just one part of the energy wasted from motorcycles - There’s also vibrations. If you’ve only driven a car, this might sound a bit strange, but think about it - unlike a car, a motorcycle’s engine parts aren’t insulated from the rider with hundreds of kilos of plastic and metal.
Vibrations have been a much lamented and ubiquitous part of motorcycling for as long as two wheelers have existed. But in the light of energy harvesting, this is a massive opportunity. In an earlier article, we’d explored how roadways are being used to harvest energy using the piezoelectric effect.
There is tremendous promise in employing the very same piezoelectric effect in order to harvest the energy lost as vibrations, from a running motorcycle. An integrated energy harvesting system that harvests heat energy, vibrational energy and the movements of the counterbalancing shaft could well help us dispense off the battery altogether.
One thing is for certain - energy harvesting is going to make its presence felt in the motorcycles of tomorrow!