Internet of Things (IoT) devices promise to enable a world of smart, connected objects, with their number expected to rapidly accelerate to billions by 2030.
However, small electronic devices typically rely on batteries that require frequent re-charging or replacement every few years, leading to high material and labour costs as well as unwanted waste.
Powering IoT devices in a cheap, sustainable fashion is thus crucial to achieve the promised vision of a connected world. Small, low-cost thin film solar cells, optimised to work with diffuse indoor light, offer a solution to this dilemma.
Perovskite PV for indoor energy harvesting
A connected world comes with the burden of batteries and unsightly extensive wiring. As more technologies are adopted into homes and businesses, the chaotic clutter of wires and the dwindling count of nearby power sockets become an increasing nuisance. The use of batteries is an environmentally unfriendly solution and replacing them on a mass scale every 3-4 years is expensive and labour intensive.
The integration of a thin film solar module within smoke alarms, motion sensors, smaller electronic displays, and other gadgets means that there is no need for batteries or external wiring and so the device can be placed anywhere that has sufficient light exposure. Solar-powered devices are of interest to both homeowners and to retailers and would eliminate the need for batteries in many indoor IoT devices.
Perovskite solar cells are a thin film technology that have demonstrated high efficiencies. Perovskite PV can provide similarly high-power density as silicon PV at a low cost, light weight, and simpler manufacturing process.
Perovskite solar cells are able to maintain relatively high efficiencies even under low intensity or diffuse light, which makes them well-suited to both indoor and outdoor energy harvesting. This is a key advantage over the conventional silicon technology that suffers poor efficiencies under indoor light. Since the perovskite material applies like an ink, the solar cells are very lightweight, flexible, and unobtrusive. They can be integrated into small electronic devices and used to power them directly.
IDTechEx has recently released a report, ‘Perovskite Photovoltaics 2023-2033’, identifying the key challenges, competition, and innovation opportunities behind perovskite PV.
Cost trumps efficiency and durability
For a lot of household and consumer electronics, high power is not a strict requirement. For example, powering headphones, sensors, and lights does not require state-of-the-art solar technology.
Solar cells with an efficiency of 10-15 % could be sufficient to operate most small and portable electronics. Durability is another typically important criterion that can be relaxed since many electronics are intended for short-term use, with consumers frequently updating their devices for newer models. The need for 25-year lifespans, as is typical for rooftop solar panels, is no longer the standard to measure by.
The key metric for the successful deployment of solar cells in consumer and retail electronics is cost. Given the increasingly high volume of consumer and retail electronics, energy solutions need to be economical. Additionally, solar technology will be competing with well-established and relatively inexpensive batteries. Solar could move into a competitive position with batteries if it were to demonstrate lower costs and greater practicality.
Perovskite PV joins a burgeoning market
Perovskite is not the only PV technology being targeted at everyday electronics. In fact, there already exist wireless headphones powered by dye-sensitised solar cells (DSSCs) that are available to purchase in shops. The household brand Adidas has recently announced it is partnering with DSSC-manufacturer, Exeger, to make their own solar-powered headphones. In addition, organic solar cells are being used on a small scale to power motion sensors and people counters.
The advantage of perovskite PV over these already commercial technologies is that it is expected to be simpler to manufacture at scale. This is because, unlike DSSCs and organic PV, perovskite solar cells do not depend heavily on complex molecular synthesis. Perovskite PV also delivers higher efficiencies, which may make them a suitable option as the functionality of IoT electronics becomes increasingly multifaceted.
To discover how the various thin film PV technologies, including cadmium telluride, copper indium gallium selenide, gallium arsenide, and more, may revolutionise the transition to green energy, IDTechEx have produced a report, ‘Beyond Silicon: Thin Film Photovoltaics 2023-2033’.
All IDTechEx reports contain detailed analysis of established and emerging technologies, their potential adoption barriers and suitability for different applications, and an assessment of technological and commercial readiness. Reports also include multiple company profiles based on interviews with early-stage and established companies, along with 10-year market forecasts.
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