nergy harvesting has been “emerging” for several years, but the technology is now poised to break out commercially, driven by developments in areas that are, themselves, emerging applications. The market got its initial acceptance in wireless building automation and control, with deployments in Europe. These opportunities spread to North America, where home automation and control technologies were added to the mix. Wireless sensor mesh networks provided challenges that energy harvesting could meet, particularly where battery use was limited or problematic. Energy efficiency, the Smart Grid, radiofrequency identification, and thin-film batteries all helped to advance energy harvesting solutions.

The question now is whether energy harvesting will remain a niche application or enable emerging applications such as wireless building control, medical devices, environmental monitoring, and tire pressure sensing. Demand can be measured by the kind and amount of products that are introduced for emerging applications. This was true for digital power management and control, which started with IC makers and moved into ac-dc and dc-dc converters. Pricing is always a critical crossover point, as well. Digital pricing had to reach parity with analog pricing.

Evidence suggests that the crossover from the “Introduction” phase to the “Growth” phase will take place within this year. This is based on product introductions from EnOcean that started in 2002. By 2005, the second generation of products was introduced, and other companies were offering new products, as well. In 2006, Electronica featured many European companies that had first-generation products, while EnOcean was already on the second generation. In November, 2009, the EnOcean Alliance publicized their energy harvesting standard, which presently contains 50 equipment profiles supporting the development of a variety of solutions for building automation. The size of the installations is increasing, and third-generation products appeared in 2009.

The appearance of third-generation products often signals the crossover into the Growth phase. Based on the timeline and company activity of the EnOcean Alliance members, energy harvesting is poised for commercial adoption, with market share increasing. The time it will spend in the Growth phase is hard to predict at this point, but this phase is marked by rapid acceleration in sales and significant gains in market share, overall. It will present a good opportunity for makers of energy harvesting solutions.

The global economic crisis has affected sales of wireless sensor devices, but companies are still seeing opportunities during the downturn. Companies like Cypress Semiconductor, austriamicrosystems and Future Electronics were interviewed on this subject, and the general consensus was that the trend toward “more intelligent machines” would continue, with more – not less – sensing functionality built into devices. For example, the number of cars being sold might decline, but the number of sensors inside each car is rising.

Some sectors have been affected more than others, according to these companies, particularly with the decline in new housing starts and other commercial construction. In a downturn, companies focus on efficiency and cost saving. Where they are able to do so, they will invest in systems that lead to more automation and greater efficiency, which in turn will lead to continued growth in the sensor market. Motion control, automotive and security systems were cited, in particular.

Energy harvesting is being deployed, particularly in building automation sensor applications. Overall, however, it is still in the development stages. Industry players indicate multiple energy harvesting technologies will most likely be required, since each technology has its own set of advantages and trade-offs, depending on the application. Energy storage appropriate to energy harvesting is also critical, and such solutions – like thin-film batteries and supercapacitors – are now being introduced. As a result, wide-scale adoption is likely to require partnerships that include sensor manufacturers, ultra-low-power electronics manufacturers and energy harvesting makers.

Power requirements of some portable devices can “overlap” with energy harvesting solutions, creating incremental markets. For example, a two-way Bluetooth earpiece device requires too much power for energy harvesting in active mode. In sleep mode, however, the power requirements are low enough that energy harvesting could be used.

Thin-film batteries are small and can now be integrated into the wireless sensor system – and theoretically last the life of the system. This also provides customers with energy storage choices: traditional batteries; supercapacitors; or thin-film battery energy harvesting. Energy harvesting devices are still priced according to the perceived benefit of not having to change or rely on batteries. Therefore, energy harvesting devices inevitably cost more than batteries at a time in their development where demand and, in some cases technology, are insufficiently developed to drive mass production.

Still, what will ultimately drive the sales of energy harvesting devices is the cost of copper versus silicon. Copper wiring is expensive. Silicon is cheap, and wireless technologies invariably rely on silicon, not copper. “Cutting the cord” is not just a matter of convenience; it is a less costly solution.

Provided by Linnea Brush, Senior Research Analyst, Darnell Group

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