Sep 24, 2023

19 min read

Beyond Batteries: How Energy Harvesting Microcontrollers are reshaping IoT

Energy Harvesting Microcontrollers are changing the world in so many amazing ways - the way our homes are built, how we go about exercising and planning our diets to how we shop for stuff, and everything in between. In this post, we check out some of the coolest use-cases for energy harvesting microcontrollers across various sectors and industries.

The internet of things has completely changed the way we go about our lives period! Today, connected technologies play a huge role in nearly every walk of human life, ranging from education, healthcare, consumer retail, food production and many more. 

Just like the internet revolutionised information transfer in the 1980s and 1990s, the IoT revolution has transformed the way we design, operate and manage the myriad processes that allow our complex and interconnected world to function. 

One of the biggest challenges that the Internet of Things had to overcome in its nascent years was the battery problem - finding a power solution that fit the bill in terms of economic viability and ecological sustainability, proved to be a formidable obstacle that delayed the explosive growth that was universally predicted for IoT technology. 

Batteries came with a laundry-list of problems that were simply impossible to oversee - they were heavy on maintenance and environmental impact and cost. But for a while, it seemed like they were the best IoT-power solution we had. A few years ago, we finally found a viable alternative - ambient energy harvesting. Energy harvesting is a technology that allows us to completely dispense with batteries in IoT applications. 

Energy harvesting , also known as ambient energy scavenging, essentially refers to any of several methods used to collect unused energy from the ambient environment and use it to power low-power electronic devices and systems. There are several kinds of energy harvesting technologies that have shown promise in recent years including RF energy harvesting, triboelectric energy harvesting, piezoelectric energy harvesting etc. These are just a few examples of technologies that are being used today in all kinds of unique applications designed to drive increased levels of energy efficiency, optimisation and user-friendliness. 

Energy harvesting Microcontrollers Transforming IoT

Microcontrollers are one of the foundational building blocks of any IoT system - microcontrollers perform the same role in an IoT network as a CPU does in your computer. Microcontrollers are the processing centres of IoT systems, providing the system with the processing power and memory that it requires to control and coordinate the various devices and processes in the network. 

Microcontrollers co-ordinate the functioning of the various sensors that are designed to collect information at the ground level. Microcontrollers control this process of data collection and furthermore, analyse the collected information along predetermined lines to extract useful patterns. They are also involved in the actuation of commands based on insights gathered from these patterns - this, in essence, is a simplified schematic that represents the workings of a typical IoT system. 

Microcontrollers can be programmed to perform various kinds of tasks depending on the exact nature of the intended application - often, they are also designed to run various kinds of software and algorithms that allow IoT systems to handle very specific tasks.

At its core, IoT is all about intelligence - packaging, purpose-building and customising computing power and setting it to work on specific challenges. Seen this way, microcontrollers are the backbone of any IoT setup - they provide this intelligence function to the entire system. In a way, microcontrollers are to an IoT system what the brain is to the human organism. 

Back in the day, microcontrollers relied on AC power, batteries or supercapacitors. Seeing as there was no viable alternative power solution, a lot of work was directed towards making microcontrollers more power-efficient. This resulted in the development of battery-powered microcontrollers that could work long periods without the need for battery replacements. As the years rolled along, manufacturers kept pushing the envelope by developing microcontrollers that featured various kinds of power-saving features such as standby and sleep modes, among others. 

But it was clear to industry insiders that no matter how efficient these battery-powered microcontrollers got, they were only a stopgap solution. By the year 2012, there was so much hullabaloo over how IoT technology was going to enable a trillion sensor world where all manner of everyday objects would be connected to one another through the internet - but to many in the know, the optimism seemed ill-considered in spite of the enormous promise of IoT. The main reason for this was that as of then, IoT devices were still overwhelmingly battery-powered. This was simply stifling the explosive growth that was on the cards for IoT technology - a trillion sensor world at that time meant a world where a trillion batteries would end up in landfills. Even if the ungodly environmental cost could be overlooked somehow, it simply didn’t make any economic sense. 

Thankfully, we found a way to get past the stopgap solution and come up with a viable alternative that really made sense - energy harvesting microcontrollers. Powered by energy harvesting technology, these MCUs could practically power themselves for life - relying entirely on energy from the surrounding environment that would otherwise go to waste. 

IoT microcontrollers typically don’t need a lot of power - just a few millivolts at a time. Energy harvesting technologies such as RF energy harvesting and piezoelectric, even in their present-day avatar, are able to meet these needs easily. Using energy harvesting means that these microcontrollers have very low environmental impact - no battery replacements - i.e no batteries that end up in landfills. Eliminating the battery entirely also means that they are more economically viable - saving businesses tons of cash that would have otherwise been spent on maintenance and battery-replacements. Energy harvesting microcontrollers bring a level of flexibility, ease of use and versatility to IoT devices. 

Use Cases Of Energy Harvesting Microcontrollers

Today, energy harvesting microcontrollers are being used in a number of IoT-based solutions across a variety of real-world scenarios. Let’s take a look at some of the most interesting and popular use-cases of energy harvesting microcontrollers across some major sectors. 


Agriculture is arguably the most important industry in the world - after all, we can only begin to think of other stuff, as human beings, after we’ve taken care of our essential needs. This fact appears all the more stark against the background of the rising global population, which is slated to touch the 10 billion mark by the year 2050! 

As the number of mouths to feed is increasing, the subject of food security is increasingly starting to weigh on us as a matter of foremost concern. Today we are seeing a dramatic increase in the use of IoT-enabled connected technologies in agriculture - in what is being called the smart farming revolution. Smart agriculture uses rich data-sets and advanced analytics to optimise processes and cut down on resource consumption. Using IoT technology also allows farmers to foresee adverse events well in advance, dramatically reducing the incidence of unexpected losses and failures. 

Ultra-low power microcontrollers powered by energy harvesting technologies are increasingly being used in various capacities in smart farming operations. Smart farms are smart because they have access to highly granular data that is picked up from the grassroots level by various kinds of sensors. Energy harvesting microcontrollers are able to harvest energy to power these sensors that can monitor the soil across various parameters such as temperature, humidity, nutrient levels, pH etc.

Imagine a large smart-farm spanning hundreds of acres of land - it would present a logistical nightmare of titanic proportions if the hundreds or even thousands of IoT sensors employed in the operation were to be powered by batteries - it would cost the owner a bomb in terms of maintenance and battery-replacements - not to mention the fact that it would be needlessly labour intensive.  Energy-harvesting microcontrollers, being 100% batteryless, circumvent this problem entirely. They can also be used for automating various processes such as irrigation and seed dispersal. 

Energy harvesting microcontrollers are also used in other capacities in farming operations - livestock monitoring, for instance, where they are used to monitor the health and whereabouts of farm animals in real-time. 

Also, in indoor farming operations and vertical farms, which are becoming more popular by the day across the world, energy harvesting microcontrollers are used for automatic climate control and precision irrigation. 


Healthcare-focused IoT technologies are dramatically changing the landscape of modern medicine. By using state-of-the-art analytics tools and monitoring technologies, modern IoT-powered health technologies are allowing healthcare providers and individuals to collaborate in amazing ways. 

Thanks to the advent of tracking devices, health monitors, AI-powered software and high-precision sensors, we are seeing the dawn of a whole new-era in healthcare and personal wellness. An era where the individual is more empowered than ever to make decisions pertaining to their health. 

Energy harvesting microcontrollers are making their presence felt in this area in some pretty striking ways. 

First up, let’s take a look at health trackers and portable monitors - today, the marketplace boasts of some pretty incredible consumer health devices - such as blood pressure trackers, continuous glucose monitors, heart rate monitors etc. It’s not hard to see why energy harvesting microcontrollers are increasingly being opted for, in these devices - uninterrupted operation is probably the most important factor for a healthcare device. No matter how good a health tracker is, if it dies on you when you need it the most, it’s simply no good - so it’s easy to see why energy-harvesting microcontrollers are being used for these applications. 

Elderly care is another area of connected health that is garnering a lot of investment and hype. Fall detection systems, remote health-monitoring systems and the like simply wouldn’t be possible in a world without energy harvesting microcontrollers. Imagine this - your nonagenarian grandma who lives by herself suffers a fall and the expensive IoT fall detector you bought her for christmas was out of charge just when it needed to be up and running - that’s just no good. 

This is just an example to highlight why batteryless technology is super-important from a healthcare perspective. 

The same goes for remote patient monitoring systems which give hospitals and healthcare workers some much needed breathing room - patients and doctors can simply rest easier if they know that these devices are not subject to unexpected battery failures and discharges.

Manufacturing Industry

Energy harvesting microcontrollers are playing a huge role in the global IIoT - or the industrial internet of things. Asset tracking, predictive maintenance, automation and energy monitoring are some of the major ways we see batteryless IoT being used today, in industrial settings. 

Predictive maintenance is when IoT technology is used to pre-emptively predict equipment failures. Predictive maintenance allows companies to save millions of dollars by avoiding unscheduled downtimes and expensive repairs. This is another area where energy harvesting microcontrollers outshine their battery-powered counterparts - think about it - modern manufacturing facilities are massive and contain several highly intricate pieces of industrial machinery - oftentimes, IoT sensors need to be deployed in highly inaccessible locations deep inside complex industrial equipment - Having to perform periodic maintenance and replace batteries on these predictive maintenance systems is oxymoronic. After all, these systems are meant to reduce the maintenance load on businesses - they simply can’t afford to come with a maintenance load themselves. 

Energy harvesting microcontrollers are also increasingly being featured in other industrial IoT solutions such as asset tracking, supply chain management and smart energy monitoring. 

Smart Buildings and Smart Homes

Smart homes are the next big thing in personalised, consumer-facing tech. The idea behind smart homes is very simple - wouldn’t it be great to offer customers a completely seamless and friction-free experience of interacting with their homes? 

Using batteryless IoT, smart homes aim to provide users with a completely integrated and immersive experience, where they get to interact with all the various appliances, components and peripherals of their home through a unified interface. 

Automation is a huge part of smart homes and so is ease of use. The more sensors are integrated into a smart home project, the smarter it is going to be. With energy harvesting microcontrollers, these sensors can be placed in various locations, offering greater flexibility in terms of usability and functionality. Another huge advantage that batteryless microcontrollers bring to the table is that they are much less expensive than battery-powered IoT devices, both to buy and to run - this makes them a much more solid proposition for home-owners who typically don’t want to spend a fortune on making their home smart. 

Moreover, energy harvesting microcontrollers have longer lifespans and are more reliable in general, which adds to the smoothness and reliability of the smart home experience. 

Energy harvesting microcontrollers can perform a wide range of tasks in a smart home context - they could be set-up to monitor various kinds of dedicated sensors - such as humidity sensors, temperature sensors, occupancy sensors etc, enabling a whole gamut of smart home sub-systems such as smart HVAC, access control, smart energy management and smart water management. 

It would simply be impractical to conceive of such large and intricate IoT systems being built around a battery-powered microcontroller. 

Automotive and Transportation

The automotive industry has been on a streak of accelerated evolution for the better part of the last two decades, completely transforming its offerings in the process. 

Cars today are loaded to the brim with some pretty serious tech, ranging from the trivial and frippery to the life-saving. For obvious reasons, a lot of innovation in the automotive space is directed towards safety. 

Energy harvesting microcontrollers are being integrated into vehicle safety systems allowing the vehicle to intervene when it senses impending danger or risk of accident. Today’s cars are safer than ever and that’s due, in no small part, to the impressive suites of sensors that they come equipped with. Energy harvesting microcontrollers are able to harness energy from friction, heat, vibration etc and co-ordinate these complex sensor suites without draining the car’s main battery. 

Batteryless sensors are also used in a number of other systems like HVAC, car security, tyre pressure monitoring systems, condition monitoring, smart suspension systems etc. 

Batteryless IoT technology is also starting to feature prominently in commercial transport vehicles as well. Logistics companies are using IoT to improve efficiency, promote driver safety and reduce costs. Energy harvesting microcontrollers are being used in applications like fleet management, worker fatigue detection, cold chain monitoring and vehicle health monitoring. 

Environment and Wildlife Protection

Energy harvesting microcontrollers are being used in many amazing ways towards environmental monitoring, ecological protection and wildlife, offering sustainable, low-cost solutions for data collection, automation and live tracking. 

Let’s start with environmental monitoring - our remote sensing capabilities have grown so massive over the last few years that today, we are able to monitor a huge variety of physical parameters such as temperature, humidity, pH levels, air quality, water quality etc. Batteryless microcontrollers are being deployed in smart cities as well as other dedicated settings to coordinate the activity of these sensors. Environment monitoring is going to be a huge use-case for energy harvesting sensors as we move into the future. 

Wildlife conservationists are also taking to the use of IoT technology in a massive way. Energy harvesting microcontrollers are used to power GPS trackers and IoT-based remote location tracking devices. These devices help conservationists monitor the whereabouts of endangered wild animals in real-time, making sure that they don’t lose animals to poaching and other avoidable threats. IoT trackers are also being used to track the health of wild animals, allowing conservation biologists to step in with interventions as and when they are required, without causing unnecessary disruption to the animals. 

Batteryless IoT technology is also being used to monitor the health of habitats and ecosystems, offering us unprecedented insight into the subtle nuances of ecological balance. This sensor data is proving to be a vital asset in efforts targeted towards habitat restoration and ecological development.

Smart Cities

A higher percentage of the global populace is moving to urban areas and this is causing severe congestion which then results in a host of undesirable problems and challenges.  IoT technologies are being used in a number of ways to counter these unsavoury challenges brought about by rampant urbanisation. 

Smart cities, in essence, are an attempt to streamline and centralise the various sub-components that go into the management of an urban area. Smart cities use IoT technologies in a number of ways. 

For instance, batteryless sensors are used in smart waste management solutions, which use IoT to optimise the way rubbish is collected, processed and recycled. Receptacles and bins are fitted with level-sensors which allow the fill-levels of garbage containers to be monitored in real-time. This means that garbage truck trips can be scheduled only when required and bins that are about to overflow can be prioritised. 

Another interesting use case is noise and air pollution detection. As cities get more congested and people start to acquire more disposable wealth, we begin to see a steep increase in pollution levels. Many smart city projects around the world are employing energy harvesting microcontrollers to oversee the functioning of various pollution-detection sensors such as CO sensors, noise level sensors etc. 

IoT devices feature in so many more ways in modern smart cities - traffic lights, public water outlets, parking spots - the list goes on. This means that the typical smart city is likely to have a whole bunch of semi-autonomously functioning sub-systems, each with its own bevy of sensors, microcontrollers, actuators and the like. It would be utterly impractical to have thousands of battery-powered IoT devices scattered all around town. Periodic maintenance and battery replacements will be a logistical nightmare. It should come as no surprise then that smart city projects opt for energy harvesting microcontrollers. 


The future of IoT is unequivocally batteryless - there’s no doubt about that whatsoever. The only question that remains is how quickly we will get to that future. We simply can’t afford to continue chucking batteries into landfills for much longer. Batteryless IoT is no longer a luxury - it’s an absolute necessity. As a global civilisation, we are at a precarious moment in history. Sustainability is no longer an aspirational ideal - it is something that we need to embody in the way we live if we want life on this planet to continue into the next century. 

Energy harvesting microcontrollers represent a step in the right direction. Batteryless IoT enables incredible innovation across several industries and solutions - the use-cases discussed above are by no means an exhaustive list. Batteryless IoT is starting to feature prominently in many other solutions such as wearables, smart clothing, personalised retail experience etc.

What makes all this even more exciting is that energy harvesting technologies are still very much in their infancy - there is still a long way to go in terms of growth and development. If energy harvesting powered IoT is already causing the kind of disruption that it is, there’s simply no telling where things can go from here. As the tech gets better, we will get to see microcontrollers that are even more efficient and can harness energy from a more diverse range of power sources. They will also be able to bring more processing power to the table, maybe even powering our laptops and phones one day. 

It is clear as day that we are going to witness large-scale adoption of energy harvesting microcontrollers across all sectors in the near future, as companies are trying to one-up each other in coming up with their own green plans, in a bid to reduce their environmental footprint. With its unparalleled ability to integrate sustainability and economic value, batteryless IoT is going to play a crucial role in shaping the future of technology.

About the author

Abishek Swaminathen

Senior Content Manager

Abishek is ONiO’s senior content manager. A medical doctor by profession, he stumbled onto a writing career almost by accident, as it were. Words have enthralled Abishek since the day he first held a book and at ONiO, he channels his inner wordsmith towards providing our subscribers with regular doses of fun and informative content.

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