Sustainable electronics disentangled

Sustainability is taking centre stage in many business sectors and the electronics industry is no exception. Yet, when we look deep into the newest electronic devices around us, are these really fundamentally more sustainable than the ones we were used to 10 or 20 years ago? In this article, we will look into how to make IoT and small electronic devices more sustainable, namely through energy harvesting. In doing that, we will introduce the SELECT project, where ONiO and a group of strategic partners are bringing together unique building blocks to enable a more sustainable future for electronics.

IoT nodes and small, portable electronic devices are an integral part of today’s increasingly digitally connected society. The number of connected IoT devices was estimated at 19 billion in 2024, projected to grow to more than 40 billion by 2030. Yet, the growth of IoT seems to be lagging behind compared to some of the earlier prognostics, which have, for instance, pointed to one trillion IoT devices produced until 2035. One of the major bottlenecks limiting further scalability of present and future IoT is power and, in particular, the reliance on pervasively spread battery-powered devices. At the same time, the scale of deployments raises deep concerns with sustainability, concerns which spread across IoT, small electronic devices, and the electronics industry at large.

Sustainability: beyond the buzz 

Despite all the buzz around sustainability over the past decades, truth be told, the core materials and the pillar principles of electronics design for mass production remain pretty much unchanged. Yet, the industry has a growing pool of more sustainable options on the table nowadays, and it’s time to turn the talk about sustainability into real, impactful actions.

It is not difficult to find grand vision statements about sustainability from large electronics corporations in the past few years. For instance, back in 2021, Samsung announced that its TV business was on a journey of “going green”. Among the action points was the introduction of solar-powered remote controls that, according to the company, could help prevent waste from 99 million AAA batteries over seven years. Another example is Logitech’s plan to reduce its carbon footprint by half, including the introduction of long-lasting hardware like the “forever mouse” concept.

Despite all the nice talk and good intentions, the electronics industry in general, and the IoT and small electronics segment in particular, is facing strong challenges with sustainability. The industry still relies on raw materials that are highly polluting (e.g. heavy metals in batteries) and greenhouse gas-intensive (e.g. conventional printed circuit board laminates), and their replacement is quite challenging from technical and cost perspectives. A resolute stab at sustainability requires looking into every single component of an electronic system and the whole system’s life cycle. The market actors that do not take this seriously risk being severely penalised by customers and consumers, who are increasingly awake to signs of frail ESG policies and greenwashing.

Energy harvesting gaining momentum

A growing number of IoT-connected devices, including the ones with low-power consumption (1 micro Watt to 1 milli Watt range), continue to rely on disposable or rechargeable batteries. Yet, batteries are far from being a good solution for powering small electronics, especially single-use coin cells or alkaline power cells typically used in such devices. Small devices reliant on batteries are a problem for several reasons. On the one hand, the limited lifespan of batteries and the high costs and burden associated with battery replacement and device maintenance can become a logistical nightmare in very large distributed node systems. On the other hand, the social and environmental problems associated with the lifecycle of batteries and respective raw materials such as lithium and cobalt. In a nutshell, batteries are bound to represent an apparent bottleneck in the massive deployment of IoT devices and a huge environmental problem. Therefore, it becomes clear that players serious about sustainability must look into batteries and consider better alternatives whenever possible. 

That’s where energy harvesting comes into play. The market arena for energy harvesting, aka Ambient IoT, is growing in importance. The use of energy harvesting for small electronics is not entirely new. For instance, portable electronic devices such as calculators and watches powered by small photovoltaic panels were popular during the 1980s and 1990s. Yet, that trend did not pick up, and batteries have taken over the business of powering small portable electronics almost entirely. Now, the growth of the IoT together with technical progress in ultra low power electronics and ambient energy harvesting are providing a new opportunity for energy harvesting. 

The emergence of new ultra low power microchips, such as ONiO.zero, and new harvesting technologies, such as Epishine’s very efficient photovoltaic cells, are revamping the interest in energy harvesting. Early examples of use cases include asset tracking, condition-based monitoring, cold-chain monitoring, building automation and home control. The total market opportunity is sized at trillions of units.

A change in mindset: electronics design for energy harvesting

The design and development of electronic devices for energy harvesting requires a fundamentally different approach than the usual development for battery power. Energy harvesting typically generates only minimal amounts of power, meaning that the electronic circuits and systems must be tuned for extreme power performance and flexibility. Besides, ambient energy is often available in variable levels and intermittent modes. For instance, light levels are variable in most environments, and the same goes for radio frequency sources, depending on proximity to antennas, routers, mobile phones, etc. Hence, power management strategies must be designed for intermittent energy availability. Summing up, the electronic systems must be capable of harvesting under the most demanding conditions (e.g. very low light or weak radio frequency sources), run from ultra low power levels, store and manage any excess energy in the best way possible. By the same token, energy budgeting and duty cycle planning are keystones for seamless batteryless operation from ambient energy - emphasizing the importance of a crystal clear understanding of the requirements for each application and use-case.

As a minimum, a functional energy harvesting device/system needs the following building-blocks: (1) one or more energy harvesters, harnessing ambient energy from light, radio frequency, motion or thermal gradients; (2) integrated circuits for control, processing and communication; (3) an energy storage/buffer element; (4) the load(s), i.e. the element(s) being powered, which may include sensors, transmitters, controllers, etc. These and a few additional auxiliary components must be mounted on an electronic printed circuit board (PCB). The SELECT project focuses on each of these elements and their seamless integration for deploying sustainable electronics with energy harvesting.

The SELECT project

The SELECT project brings together six partners on the quest for sustainable electronics. The project is co-financed by the Eurostars program.

ONiO leads the way with its ultra low power microcontroller tailored for energy harvesting, ONiO.zero, at the core of the project. ONiO.zero combines an ultra power-efficient RISC-V CPU with an advanced power management integrated circuit (PMIC) and wireless radio communication on a single microchip. Epishine provides highly efficient and versatile printed organic photovoltaic cells optimized for indoor conditions, which are best-in-class with respect to sustainability. Ligna Energy owns unique supercapacitor technology that leverages bio-based sustainable materials and roll-to-roll manufacturing methods for green, safe and ultra-thin energy storage. Jiva Materials offers Soluboard®, a fully recyclable and biodegradable rigid PCB laminate with a 67% lower carbon footprint than glass-fibre and epoxy technologies used in conventional FR-4 PCBs. These four partners put in the key ingredients for the SELECT recipe. The consortium is complemented by two end-user partners: Pricer, a partner for in-store communication and digitalization and a leading supplier of Electronic Shelf Label (ESL) solutions, and 4MOD Technology, a versatile company specialising in the design and engineering of remote controls and IoT solutions.

The team will tune each of the key ingredients (microcontroller, photovoltaic harvester, supercapacitor, Soluboard® PCB), focusing on solving the challenges involved in their orchestration to work optimally together. These components are already available now, but their combination brings benefits to the next level. The project will generate reference boards and development kits combining these key elements - i.e. forming a SELECT platform ready to use in the development of a new order of sustainable IoT and small electronic products.

The new SELECT platform will be able to serve a wide range of applications across the IoT and small electronics market verticals. During the project, the partners will focus on two lead applications: ESLs, under Pricer’s leadership, and remote control units, headed by 4MOD Technology. The key outputs of the project will include reference designs and prototypes customised for these two demo cases. But the SELECT platform will be ready to target an array of additional product categories, with a view to fast-tracking energy harvesting-based solutions to real market products that can effectively compete with the current battery-based standards.

SELECT is using some of the most sustainable components available, with benefits in toxicity and contamination of the environment and particularly in carbon emissions. A back-of-the-envelope calculation shows a potential for saving at least 150.000 tonnes of CO2 equivalents per year if the SELECT solutions were rolled out across the ESL and remote control markets (estimated at 300 and 400 million units per year, respectively). This is the equivalent of taking over 100.000 combustion engine cars off the streets. These savings were estimated from removing single-use batteries and using photovoltaic harvesters instead, plus replacing FR-4 PCB with Soluboard®. The SELECT project includes systematic Life Cycle Analyses where the environmental benefits will be studied in detail and computed in a proper manner. In any case, looking at these ballpark calculations for the two test cases only, and considering the total space of applications that can be targeted by SELECT - extending from industrial IoT sensors to building automation, electronic tags and trackers, wearables, etc. - the extent of the project's impacts can be massive.

Conclusion

The tools to make IoT and small electronic devices way more sustainable are already on the table today. But we need to move from individual eco-friendly components to systems fully orchestrated to work optimally with more sustainable options such as energy harvesting. The added value of the SELECT solutions lies in the seamless integration of sustainable building blocks to craft an electronics development platform built with a 360º view on sustainability, from individual components to system level. 

Besides focusing on performance and sustainability, the SELECT platform will enable the deployment of very cost effective products and systems, especially when considering system bill-of-materials and lifetime costs. By removing batteries and simplifying electronic systems, SELECT will reduce the component count and footprint of electronics, with a positive impact on costs. Hence, SELECT will bring unprecedented possibilities in terms of thinness, material minimization and low cost of end devices. Moreover, with no battery changes, maintenance and lifetime costs will be much reduced, bringing logistics and cost benefits for the end users. Finally, for many product categories, the device’s lifetime will be extended and costs with end-of-life, namely recycling, will also be reduced.

The SELECT partners' ambition is bold: mastering energy harvesting while redefining electronics with sustainability at the core. Power is on!