Darnell Group Special Report: Half-a-Billion Energy Harvesting Nodes Identified

April 05, 2011 by Jeff Shepard

Energy harvesting has emerged onto the power electronics scene and has offered increased revenue to companies that got in on the ground floor. Energy harvesting is an opportunistic technology that is being implemented in niche segments that have "environmental" challenges. If taken cumulatively over each year of the forecast period, worldwide unit sales of energy harvesting nodes will result in 630.5 million units being sold between 2010 and 2015.

According to Darnell Group’s "Energy Harvesting Technologies & Energy Storage: Worldwide Forecasts, Third Edition" report, the growth of energy harvesting technologies parallels the growth of wireless sensor network (WSN) and wireless control systems in general. Such systems have had a slow but steady evolution, and there are currently hundreds of vendors in the WSN market. The market is set to take off, but at a slower pace than expected.

This highly-quantitative, 71-page report includes 28 tables, 17 graphs and 7 figures to provide a detailed numerical picture of opportunities and trends in this rapidly-emerging market. The majority of sensors installed in the world are still wired, and some industry analysts project that over the next ten years, WSN will constitute no more than 10% of the wireless sensors that are sold. Challenges include rival standards and large numbers of competitors. Some reports indicate that the sector "is ripe for consolidation."

Initially, ultra-low power was an ideal match for wireless sensor mesh networks, primarily in building and residential automation and control. That is still the case, although the problems associated with such implementations persist. For example, the presence of heavy machinery in factory automation applications can interrupt wireless signals.

This, combined with the importance of getting dependable, detailed machine data, has convinced many customers that (for now at least) wired solutions are best. The conservatism in factory automation has also inhibited the adoption of wireless communications networks, which includes sensors, operator terminals, programmable logic controllers (PLCs), remote IO, drives and wireless access points.

In spite of this, an increasing number of companies are beginning to experiment with wireless products that have been specifically designed and ruggedized for use in a factory environment. Will this lead to a bigger market for ultra-low power devices, or will the "wait-and-see" attitude prevail? So far, the market for energy harvesting nodes has been very consistent as far as applications are concerned.

Building Automation has led the way in terms of wireless implementations that can benefit from an energy harvesting solution. This will continue over the next five years, with radio frequency ID (RFID) applications gaining traction, as well. RFID is a very different market than the other energy harvesting segments included in this report, however. Its characteristics are sufficiently unique to warrant a forecast both with RFID and without it.

A big change has been in batteries. Primary batteries are still used occasionally as back-up power in energy harvesting applications, but new technologies, such as thin-film rechargeable batteries, have pretty much taken over the market. Even though primary batteries will see declining growth rates in nearly all applications, a few segments are expected to use primary batteries with energy harvesting. The reasons for this are discussed, along with the potential market size.

Ultra-thin batteries are optimized for these applications, and they co-exist peacefully with energy harvesting solutions. STMicroelectronics has even signed a licensing deal with Front Edge Technology to gain access to the latter’s ultra-thin lithium battery technology. A "pure" energy harvesting solution (i.e. one without batteries) is still elusive, however, and such implementations make up less than 10% of most applications.

Practical and cost-effective are the operative words today. Even if a new technology can solve "the problem with batteries," if it’s more expensive, the customer probably won’t pay for it. The falling cost of wireless-enabled products is a further incentive for companies to convert from a wired to a wireless network, or to use both types of networks alongside each other. The adoption of a wireless network for condition monitoring, for instance, can save component costs.

With cost and energy efficiency driving adoption, the energy harvesting market is expected to reach an inflection point in the next couple of years. Second- and third-generation products are already on the market, and as components become more widely available commercially, prices will come down across all application areas.

Makers of power management ICs and thin-film batteries are doing particularly well in the ultra-low power space, and their success will inevitably lead to increased success for energy harvesting technologies. The worldwide dollar market for regulator ICs used in wireless sensor network building automation systems is expected to grow 10% in 2009 and then increase to about 20% between 2009 and 2010.

The economic recession has been both good and bad for energy harvesting: On the one hand, overall sales are down and companies are carefully eyeing where they do spend money. On the other, the need to save money will push wireless installations, which are often cheaper to deploy than wired facilities. Choosing the right markets is important, since wireless solutions (and energy harvesting) are not optimal in all applications.

Home and building automation have been targeted for several years; environmental monitoring and medical applications are good possibilities over the next few years. Some applications, such as automotive tire pressure monitoring systems (TPMS), are being mandated; others have very specialized requirements, such as military applications.

A final shift is expected to come in the energy harvesting technologies themselves. Currently, photovoltaic solutions dominate the energy harvesting market. The mechanical vibration/piezoelectric segment is slowly catching up, however, and is expected to eclipse photovoltaic solutions by the middle of the forecast period.

This is primarily due to RFID, TPMS mandates (which are already in effect in North America) and Building Automation. Thermoelectric energy harvesting solutions will experience healthy growth, but they are still too expensive to realistically challenge photovoltaic and mechanical solutions during the forecast period. Radio frequency will remain a small market in the near-term.

Each of the forecasts in this report discusses the various drivers that are likely to push the adoption of energy harvesting in the selected applications. A combination of factors is still molding the market, with clear trends not expected until the end of the period. The most critical factors have been identified, however, and these are the basis for the forecasts presented here.

You’ll find complete information on this unique and important report here.