The construction industry is starting to replace copper with silicon, and that’s just one of the potentially big applications for wireless electronics, powered by energy harvesting, argued Jeff Shepard, president of the Darnell Group.

Darnell forecasts sales of more than 200 million units for energy harvesting and thin-film batteries over the next 24 months, primarily driven by wireless connections and energy harvesting replacing power and signal wiring in buildings. The economics are compelling. Shepard noted the example of a recent warehouse that installed a wireless system instead of traditional copper wiring and saved $70,000 in material cost and a week in installation time.

“And that’s using today’s relatively expensive batteries and harvesting technologies that are just starting production,” he said, “before the typical cost reduction of silicon with volume.” Wireless building security and energy management systems are already in common use in Europe, he noted.

Making real inroads in commercial applications of energy harvesting is the Siemens spin-off EnOcean GmbH, with its wireless light switches and sensors now reportedly installed in more than 10,000 buildings, primarily for cost savings in commercial projects in Europe. “The goal is wireless controls,” said applications engineering manager Eugene You. “And that means no wire for power either and no battery.”

Also key to enabling innovative wireless applications are tiny thin-film batteries that can be embedded into tiny spaces, and perhaps continually trickle charge with tiny amounts of harvested energy.

Infinite Power Solutions said it plans to start commercial production of its thin-film batteries in 3Q08, initially for wireless sensors for semiconductor test wafers and military applications. The sturdy postage stamp-sized batteries withstand heat and pressure so that they can be directly laminated into smart cards or embedded into PCBs or chip packages. Although the tiny battery also has a tiny 0.7mAhr capacity, it can be recharged thousands of times with tiny charges and has a minimal self-discharge rate of 1 percent per year.

“We’re using common thin-film deposition technology, but with foreign materials,” said CTO Bernd Neudecker. “And we need different handling of materials within the chamber and RF-compatible chambers.” But ramping volume production is going to take volume suppliers.

“If we’re going to be making 100 million batteries for the Samsungs and Motorolas of the world, we’re going to need the equipment vendors and target manufacturers to do 100 million square inches a year,” he added. “We really need the big boys playing here. It’s up for grabs, folks. Who wants to step up?”

Taking a different approach for its tiny flat battery is Solicore Inc., which uses a polymer matrix electrolyte for the core of its flexible 3 V lithium thin-film battery, which it is producing in volume for the powered card market. The company uses a roll-to-roll process, coating on an electrode material, overcoating the electrode with a polymer electrolyte separator, adding the anode, folding over the sheet to encase the anode, punching out units of the desired size, and laminating them in aluminum foil.

“Our capacity is 2 million units per month and we’re now flat out, 24 hours a day and in the midst of expansion,” said CEO David Corey. “We have seen tremendous demand for our Flexion batteries in 2008, and we currently have orders well into 2009. We’re currently expanding to double our capacity to 4 million units per month by the end of 2009.”

Speakers from Solicore, Infinite Power Corp., EnOcean, Cree LED Lighting Solutions, Darnell Group, USDC, Strategies Unlimited, and other organizations will be speaking at the Emerging Markets TechXpot at SEMICON West.