Ambient IoT – The Future of Sustainable IoT

As companies strive to create greener and more ecologically conscious products and device ecosystems, the world of IoT is constantly adapting to embrace this shift. From smart home devices like locks and sensors, to industrial devices like factory monitoring equipment and machinery sensors, battery-less and low-power-consuming solutions are revolutionizing and reshaping the future of sustainable IoT.

The Problem with Batteries

The IoT is all about creating an inter-connected world; where innovative and intelligent devices interact seamlessly with each other to transform how we experience technology in our everyday lives.

However, every device needs to be powered to achieve this level of interconnectivity. While this power can have many sources, the most common and simplest source for IoT devices is a traditional battery.

So, what’s the problem? If traditional batteries are the simplest answer, why are consumers and device makers suddenly striving for a battery-less future?

Well, let’s get into it.

First, batteries are a menace to the environment. Not only is their disposal inconvenient, but improper disposal and recycling practices cause significant harm to ecosystems. Every year, more than 15 billion used batteries find their way to landfills. They contain acid and toxic metals like lead and mercury, which leads to the release of about 900,000 tons of hazardous, soil-and-groundwater-polluting waste into the environment.

Second, batteries have a limited lifespan. This requires constant replacing or recharging, which can be costly and time-consuming depending on the type of device, how much power it consumes, and how frequently the battery needs to be replaced or recharged. All of this adds up to the maintenance cost of the device.

Third, as the number of connected devices in a network is expected to grow rapidly, so will the number of batteries. The concept of IoT connectivity benefits relying on batteries threatens their adoption and scalability.

Ambient IoT - A New Class of Connected Devices

To address the challenges and drawbacks that batteries impose on smart connected devices, pioneers in IoT are now navigating their way into a new, energy-aware, battery-less future of connected devices. This realm of IoT, collectively referred to as Ambient IoT, aspires to achieve seamless connectivity without the environmental and functional implications that come with it.

What is Ambient IoT?

Ambient IoT refers to the class of connected IoT devices that harvest naturally available energy sources such as magnetic electric fields, light, thermal differential, kinetic energy, and vibration to power them. These sources, also referred to as Ambient sources of energy, can reduce the dependency on -- and potentially even replace the need for -- batteries, leading to products with flexible form-factors lower BOM costs and vastly longer product lifetimes.

An important term here is harvesting. Ambient IoT and Energy Harvesting are different yet related concepts. Energy Harvesting refers to the process of harnessing, transforming, and then storing energy from various ambient sources like solar power, RF waves, and physical vibration.

Ambient IoT leverages Energy Harvesting technologies to power a new era of devices targeting applications that rely on short-range, wireless connectivity. These applications include smart home devices like switches and locks, smart buildings, asset tracking, smart metering, and factory automation.

However, before we jump to these applications of Ambient IoT, let’s dig deeper into why energy-efficient solutions are not only essential to IoT but can also potential game-changers.

Why Should Designers Embrace Ambient IoT Designs?

With Ambient IoT, our beloved smart devices can now rely on natural sources of energy to draw power and maintain connectivity instead of relying on conventional batteries. These sources (like light, heat, motion, etc.) extend the device’s lifetime and notably reduce the detrimental impact that batteries have on the environment. But how is relying on these sources for power any better than relying on traditional batteries? Why is there a sudden shift to powering devices through renewable sources of energy? Well, there are quite a few reasons:

Enables a Greener Future for Customers
Not relying on batteries- or reducing the amount consumed by smart devices- contributes to a healthier ecosystem. As previously mentioned, improper battery recycling or disposal practices contaminate the environment by releasing toxic metals like lead, cadmium, mercury, and lithium.

Improves Scalability
An IoT solution is only as strong as its network size and scale of adoption. Having a denser and more reliable network can potentially increase the range and frequency of communication between devices. For example, communicating with nearby gateways is important in asset tracking to ensure better traceability and reduce the risk of losing valuables. Another example is a smart building and how its energy rating can be improved if more sensors are deployed. If each of these sensors requires a battery cost and replacement, the benefits at scale are diminished. Integrating battery-less nodes into the network can help mitigate this problem. Additionally, the constant need for battery replacements increases demand, and when the supply cannot keep up with this rising demand, it causes scalability issues.

Helps with Long-Term Cost Savings
Not relying on traditional batteries to power your device can impact the BoM) cost in quite a few ways. On one hand, it may decrease this cost by eliminating the need to constantly replace batteries. On the other hand, it could also increase the BoM cost as energy harvesting components like Integrated power management systems may be more expensive to install than traditional batteries. However, the long-term cost savings from reduced maintenance and extended lifespan of battery-less devices often outweigh the initial increase in the cost of developing these devices.

Additionally, traditional batteries must regularly be replaced or recharged. This maintenance is not only time-consuming but also adds to the overall cost associated with owning and maintaining a smart device. In the US alone, an average household buys over 90 batteries annually, and most of them do not even have a 10-year lifetime.

Fosters Innovation
Battery-less architecture allows for a more compact device by eliminating the need for the previously reserved socket for traditional batteries. This is particularly beneficial for devices like wearables and implanted medical devices where size and weight are essential considerations. This battery-less design also helps create more durable devices, eliminating the risks associated with battery degradation and failure. Additionally, the saved hardware space can also be used to add more peripherals, driving innovations in the boards' physical design and technical features. This push towards battery-less devices also serves as a catalyst for the development of eco-friendly and sustainable innovations in IoT.

Unlocks New Use Cases
By fostering innovation, Ambient IoT can also unlock new use cases that would not have been convenient to implement with a battery-reliant architecture. For example, in smart agriculture, applications for crop management that are installed in greenhouses are very difficult to replace after installation. They require sensors to be installed all over the field, and having to replace the batteries in these sensors is time-consuming, labor-intensive, and costly. The notion of running wires to power these systems is even more impractical because they are prone to breaking due to the harsh conditions of the application. The abundance of solar power in a greenhouse or the vast amount of vibration created on machinery can easily be harvested to power these sensors.

While all these advantages make a great case for Ambient IoT, relying on natural sources to power smart devices also poses some challenges. An ambient IoT source can only produce limited amounts of power compared to traditional batteries. This makes them more suitable for smart devices that consume low to moderate amounts of power. Furthermore, Ambient IoT is best suited for devices that are designed for a specific function like beaconing, brief periodic advertisement, or intermittent connections to a gateway for data logging status and have low reconfigurability. This is also because of the limited power supply from energy efficient methods. However, these types of devices have the ability to be energy conscious and therefore make energy-awareness based decisions dynamically. For instance, based on available energy, an IoT radio may choose to shorten its payload and interval and instead opt to remain in a deeper sleep mode for longer while it regenerates more energy.

Ambient IoT Applications

With Ambient IoT, developers can now build devices using an energy-friendly platform that minimizes power consumption, improves device longevity, and decreases the device’s reliance on traditional batteries. Many current IoT applications can potentially switch to ambient and power-optimized solutions.

• Smart Buildings: Kinetic pulse-harvesting battery-less doorknobs and light switch controls using Zigbee Green Power helps decrease the need to constantly replace batteries and render an office building more intelligent by allowing switches to be moved around different spaces without the need for renovation.
• Asset Tracking: Tracking and managing warehouse inventory is challenging, but asset tags and other tracking systems make it so much easier! However, they need to have their battery replaced quite so often. Ambient IoT provides battery-optimized solution that reduces this reliance on batteries or allows for adoption of battery-less tag design which offer a significant improvement from manual barcode scanning.
• Agriculture: Sensors are used to help monitor and map greenhouse and vehicle conditions, get real-time information on temperature, humidity, and other environmental factors, as well as monitor cattle and their health in the barn. Battery-less solutions makes the implementation of smart agriculture easier by eliminating the need to constantly replace batteries in sensors that help automate farming.
• Smart Home and Appliances: Smart home appliances such as door locks, faucets and switches help automate residences and build a smarter, more-connected home. In this use case, battery dependencies and their associated replacement costs can be eliminated by using energy-harvesting design. power harvesting generators.
• Gaming Electronics: Indoor solar and RF powered television remote controls, and computer keyboards provide an energy-efficient and cost-efficient Bluetooth solution.

Some other key applications include tire pressure monitor sensors (TPMS), ESLs, factory automation, and predictive maintenance machine monitoring using vibration and thermal energy harvesting.

Silicon Labs and Ambient IoT

As we venture into a more connected and intelligent future of smart devices, it is important that leaders in IoT do not fall behind in this shift. It is imperative for experts and companies to invest time and resources into Ambient IoT and other energy-efficient solutions and stay ahead of the curve to meet their ESG goals. This will help us navigate a more sustainable future of IoT and help us strike a balance between technological advancements and environmental sustainability.

At Silicon Labs, it is our mission to enable wirelessly connected devices that transform industries all over the world. Achieving seamless inter-connectivity in an increasingly digital world is our utmost priority. To help ensure the future of IoT is ecologically responsible, we have now optimized our xG22 line of SoCs (BG22E SoC, MG22E SoC, and FG22E SoC) to include features that will support energy harvesting.

With a dual Cortex-M33 and Cortex M0+ radio core, the xG22E is our most energy-friendly SoC to date. It is the ideal choice for developers who are looking to build low-power consuming, high performing smart devices, that function on a battery-optimized, energy-efficient platform. It is the ideal choice for device-makers looking to implement a solution that offers an ultra-fast, low-energy cold start, low-energy deep-sleep wake up, and efficient energy mode transitions that mitigate harmful current spikes and prevent damage to the storage cells.

In addition to our radio board and xG22E Explorer Kit, we are e-peas , an industry leading provider of PMIC, to develop an Explorer Kit Shield. This kit consists of the Explorer Kit and 3 shields that fit onto the Explorer Kit board. The first shield allows for experimentation with alternative battery chemistries and supercapacitors, the second shield is dedicated for kinetic/pulse harvest applications, and the third shield allows developers to experiment with dual harvest sources simultaneously.