Energy Harvesting is making Smart Cities even smarter

Smart cities have been touted as being the future of urban living for about two decades now. As IoT technology established a strong foothold with newer, more robust IoT-based solutions entering the market, the promise has mostly come good. The numbers speak for themselves - it is reported that by the year 2025, investment in smart city infrastructure will grow to more than $100 Billion! 

 As an increasing number of urban conurbations around the world embrace smart technology, the market has been pushing for ever more efficient and safe technological standards. Traditionally, smart city systems have employed battery-powered IoT microcontrollers and sensors. However, batteries represent a rather clumsy power solution for IoT devices - environmentally dubious and highly inefficient; it became very clear to all involved parties that the future of smart technology, be it in smart cities or otherwise, was not going to be battery-powered.

Explosive Growth Needs Sustainability

Demand for batteries is growing at a breakneck pace. This trajectory of growth, if it continues, is simply not sustainable. As IoT sensors become cheaper and more reliable, connected technologies are witnessing higher adoption rates. With time, our sensing capabilities and technological prowess in the area will only get better, which will lead to more cities around the world investing in smart city technologies in some way, shape or form. 

Today, the initial investment required to set up a robust and complex IoT system over a city-wide area is rather un-intimidating and approachable. This means that there is a virtuous cycle of increased demand leading to increased supply and vice versa. 

Sensors are getting cheaper, and they are better than ever. At this rate, we will soon see enormous amounts of money and effort being directed towards setting up smart city projects around the world. 

Smart cities represent a rather large-scale IoT application in terms of size and complexity. The principles involved are no different to an industrial IoT or smart farming setup, but the sheer scale is much bigger. 

Smart cities typically consist of a number of sub-components that work in tandem with one another. This means that there is quite a lot of IoT infrastructure likely to be scattered around a sizable urban area. 

Here’s where we encounter the first problem with battery-powered smart city solutions - batteries run out after a finite lifespan. In the meantime, they require check-ups and periodic maintenance. When they do run out, they need manual battery replacements. While these may not sound like huge challenges, indeed, they are when one factor in the sheer scale and size of smart city operations

More importantly, though, batteries represent an environmental threat of epic proportions. Accounting for a huge chunk of toxic waste released into the environment, batteries don’t make for a remotely sustainable solution. This is particularly ironic because around the world, when smart city projects are announced to the public, the environmental angle is almost always strongly emphasised. 

This is not unfounded - when done right, smart city systems can bring an enormous amount of efficiency to any city, reducing waste and misallocation of resources. Seeing as that is the case, it would make no sense whatsoever for a sustainability-oriented project to employ large numbers of batteries. 

Battery Free IoT 

In the past few years, battery-free IoT has emerged as a highly sought-after area of innovation within the tech world. With the emergence of multiple energy harvesting technologies, such as RF energy harvesting and piezoelectric energy harvesting, an increasing number of voices are coming out in support of IoT solutions that dispense with batteries altogether. 

Energy harvesting technologies are a breakthrough in that they allow small semiconductor devices to be entirely energy-autonomous - by harvesting small quantities of ambient energy from the environment and converting it into usable electrical energy.  Energy harvesting allows us to design microcontrollers that are 100% battery-free. 

Energy harvesting can be used as an IoT system’s sole power source. Alternatively, when the demands of a particular application are too intense, they can also be used to augment the life of batteries, making for incredible value while representing a move forward in the right direction in terms of sustainability.

Today, thanks to the increasing availability of these technologies, smart city projects around the world can choose IoT devices that are 100% self-powered. Battery-free microcontrollers and sensors simply make more sense in every way. Ultra-low power technology has progressed so quickly in recent times, which means that today’s IoT microelectronics are extremely power efficient, requiring millivolts of power to stay connected. 

With Bluetooth 5.0 establishing itself as the standard of choice in smart city IoT applications, cities can dramatically reduce the amount of power consumed by their smart city infrastructure. 

Battery Free Smart Cities

Let’s take the example of a traffic management system. Traffic management has emerged as one of the most widespread smart city applications worldwide. A clever traffic management solution goes a tremendous way in making cities more livable while also freeing up a significant amount of resources. 

Advanced IoT-based traffic management solutions, such as adaptive traffic control and real-time traffic analytics, can make cities safer and significantly bring down congestion. IoT sensors integrated into sidewalks and roads send information about traffic flow to the back end, where the data is crunched, and the necessary interventions are actuated. 

These systems can be incredibly beneficial in several ways, as smart cities around the world are beginning to find out. These systems employ a huge number of sensors. They are incredible feats of technology - think about it as a huge number of fully functional autonomous computers scattered all around town, communicating with the internet by themselves, automatically, all the time. 

Sounds a bit wild, doesn’t it?

That’s exactly the case, though. Each node in the network is essentially an autonomous computing device. Now, imagine the complexity and scale of such a network operating at a large scale - with thousands of sensors positioned in various strategic locations around the city. 

If all these microcontrollers and sensors were battery-powered, it would be a logistical nightmare. 

To keep these systems in running order, they would have to be monitored pretty much all the time, which makes for huge losses in terms of man-hours and costs. And no matter how good the periodic maintenance is, there will always be scope for malfunctions and unexpected downtimes, which doesn’t sound very smart at all. 

With battery-free sensors or energy-harvesting augmented sensors, these problems are circumvented to a large extent. City administrators can breathe easy knowing that they won’t have to worry about these sensors until the very end of their lifespan.

And what’s even better is that these battery-free microcontrollers are actually a whole lot cheaper to produce than battery-powered ones. When the battery is eliminated, there is a 30-40% reduction in material costs. When you add the savings from not replacing batteries, it adds up to quite a lot. 

Applications aplenty

Smart cities can draw immense benefits from energy harvesting technologies. Energy harvesting is being employed across a wide range of use cases in smart city projects today - waste management, smart street lights, air pollution monitoring, smart parking and smart fleet management are just a few examples. 

All these applications have one thing in common - they operate using the same basic blueprint - sensors placed in various locations collect various kinds of information and send it to a central system where the information is analysed to glean useful insights. These insights are then used to actuate timely and targeted interventions aimed at more efficiency.

Think of any one of these applications, and you will see a pattern emerging - batteries will always be a painful and cumbersome power solution in comparison to energy harvesting. 

For instance, smart parking sensors are used by many cities to provide commuters real-time updates about available parking spots - now imagine city workers hauling themselves all over town trying to figure out which of these sensors require battery replacements. That’s simply not a good use of public resources. 

Reducing Consumption Is Key

We are stepping into unchartered territory as a species. The challenges that await us in the near future are entirely new and are not at all for the faint of heart. Food shortage, energy crisis, climate change, overpopulation, deforestation, soil degradation and water pollution are not trifling issues by any stretch of the imagination. 

As we continue to grow past the 8 billion people mark, these are not issues that can be slept on - there is a really urgent need for collective introspection and decisive action. It is clear for everyone to see that if our present-day battery consumption trends continue for any significant period of time, life on earth will have to pay a massive price. 

Battery-free IoT technology is a nifty alternative to battery-powered IoT, and that’s definitely a step in the right direction. But if we are to truly emerge victorious in our fight for a more sustainable future, we will need to make dramatic changes to our consumption patterns on every level - individual, social, national etc. 

Smart cities are a rather pertinent example to highlight this because it’s something that pertains to millions of people at a time. Smart city projects switching to battery-free power solutions just gives out all the right messages.