A brief history of energy harvesting
Just a few years ago, it would have been impossible to conceive of powering sensors and devices using energy harvested from the environment. Today, we actually have commercially viable products that are powered entirely by energy harvesting based solutions.
In a nutshell, what is energy harvesting?
So, what is energy harvesting, then? To put it very simply, energy harvesting refers to any technology that allows us to collect and store tiny amounts of energy from the surrounding environment and use it to power an electronic device of some sort.
To be fair, most of us know from middle school physics that every square inch of space around is rife with energy, in the form of radio waves, wifi signals, sound, heat etc. Energy harvesting technologies are all based on this simple premise - why let all this free energy go to waste? Why not find a way to use it?
That is a rather simplistic explanation - sure the premise may be simple enough but obviously making a usable, practical technology out of a crazy “what if?” takes a lot more than just imagination.
Energy harvesting explosion
Energy harvesting has charted quite the impressive growth trajectory in the past decade or so. In just a few years, energy harvesting has gone from inhabiting the realm of fantasy and future to actual, concrete reality.
It was as late as 2015 when energy harvesting being a potential alternative to batteries for powering ultra low power node devices and sensors was just mere talk.
Even so, there were numerous question marks and doubts that hung over how it would work outside a laboratory. And here we are - as of 2021, not only is the technology feasible outside the laboratory, it is actually finding hundreds if not thousands of real-world applications.
Not only is energy harvesting a laboratory possibility today - It is finding large scale commercial application in various forms - piezoelectric, radio frequency, thermoelectric and piezoelectric just to name a few.
And these are just the big ones - There are more, well, left-field, options, if you will as well - energy harvesting solutions that don’t quite have the same popularity or large scale commercial viability - but nonetheless serve to highlight just how much research investment is being poured into this area at the moment.
IoT and energy harvesting - made for each other?
The history of energy harvesting goes hand in hand with the history of the internet of things. To put it even more simply, they are simply made for each other it would seem.
Why, you ask?
The answer is quite simple really. The internet of things, as far back as when it was still just an idea in it’s infancy, was predicated on a very simple question -
“Why should internet connectivity, with all the goodness it brings, be limited to traditional computing devices?”
The idea was that by connecting the little everyday objects around us to the internet, we could usher in a truly hyperconnected era where information hyperflow would simply blow holes through current conceptions of what’s possible and what’s not.
If that sounds like a lot of hyperbole, that really does capture the bullishness and sky-high expectations that surrounded the internet of things a few years ago. Predictions made by reputed consulting firms like Gartner laid some truly ludicrous figures on the table - it was expected that there would be a trillion (yes read that again!) connected objects in the world by 2025.
The optimism was not entirely unfounded though. There really was a lot of reasons to be that excited. Allied technologies were catching up at a brisk enough rate. With artificial intelligence, inexpensive processing power and machine learning all coming together, it really did seem like that’s how quickly this ridiculous dream of connecting ALL objects to the internet would come into being.
Unfortunately, that didn’t come to pass.
There’s many a slip twixt the cup and the lip
So what went wrong? Why is it that in actuality, we didn’t come anywhere close to even 100 Billion connected devices, let alone a trillion?
Think about it. Laptops, tablets, phones and other such traditional “connected” devices use power. And almost universally, it’s batteries that they rely on for said power. Now, extrapolate this onto a model where instead of tablets and phones, we’re talking about, say, connecting a thousand sensors, placed in various hard-to-reach spots within a manufacturing unit, to the internet.
It doesn’t take a genius to figure out that relying on batteries means that you can’t really be as liberal as you’d want with the number of devices you deploy in the first place. Except, that’s the whole idea of the internet of things - literally going wild with connecting pretty much anything and everything to the internet and benefiting from the awesome flow of data that ensues.
Except, if this model was based on using batteries, then there are some painful real world problems that would come in the way.
AND THEY DID!
Batteries run out. Which means, they need to be replaced. Moreover, if you are using thousands of batteries over a large facility, then you would need to schedule regular maintenance in order to ensure that you don’t have any undue delays, which could prove costly.
And all this costs money. Money which you would want to save in the first place if you are to invest in flooding your facility with sensors.
And that, in a nutshell, is why the internet of things never quite reached its predicted zenith. Batteries proved to be a bottleneck of titanic proportions.
A huge buzzkill, if you will. And the buzzkill doesn’t stop there. Say, there was theoretically some way to lower the cost and overcome the maintenance problem, there is still the grave environmental cost of just dumping billions upon billions of batteries into our ecosystems.
So, getting back to the point we were making, energy harvesting is more or less the white knight that salvaged this hopeless situation for the internet of things. With energy harvesting, this seemingly insurmountable pain-point of replacing and maintaining batteries could be circumvented.
Self-powered sensors in an IoT world
With energy harvesting, we got self-powered sensors that didn’t need any external source of power. These technologies enabled tiny sensors and ultra-low-power chips to run on packets of energy harvested from the surrounding environment.
If there’s anything that qualifies as magic, this has got to be it - chips that literally draw power from the air around us.
Ok, we digress.
So, how do they do this?
Our surroundings are full of all sorts of energy - wi-fi, radio waves, dissipated heat waves etc etc - you get the gist - we live surrounded by endless amounts of energy that’s just waiting to be tapped into.
And energy harvesting technologies do just that - they let us tap into this near endless source of energy and use it to power our low-power devices - like the wearables, trackers and health monitors that we’ve come to love and take for granted in our modern, fast-paced lives.
If that isn’t magical enough to blow your socks off already, get this - think about just how many batteries this would stop from ending up in oceans and forests, polluting them irreversible. Think about just how priceless it would be to those children whose lives are permanently ruined by working in Cobalt mines.
I guess the point we’re trying to make is that energy harvesting is a force for good in the world, whichever way we look at it. And if we sound like we’re a bit too passionate about it, it’s because we really are!