It's just another one of your typical entrepreneurial stories. A 36-year-old professor sits at home vexed by a common problem. His wife complains it's a waste of time and asks why he doesn't focus on something important. He perseveres, patents his inventions, and finds angel financing. Before long, he gets some early adopters from local government institutions to pilot his invention. And the rest is history -- another cleantech success story in the making.

The twist is, that story took place 125 years ago. I looked up Warren Johnson's life after attending Johnson Controls' recent "Cleantech Analyst Day" and came away fascinated. It's been only a few years since that the vision of cleantech emerged about venture capital and underfunded start-ups (which was not that different from Mr. Johnson's day). But as Joel Makower wrote in this year's State of Green Business report, the worlds of clean technology and green business "seemed like a Venn diagram that was yet to be -- that is, two circles trying to overlap." For a large part of Johnson Controls business, that Venn diagram has become an almost a perfect circle.

Nearly half of Johnson Controls' (JCI) business could fall under the cleantech label. (The other half provides components to the automotive industry.) And while the theme of the "analyst day" was clean technology, the real topic was energy, or more specifically energy systems. Warren Johnson's early thermostat could not operate without mechanical dampers and flues, and the current offerings from JCI require the same systems-oriented approach. This is true of its battery business as well as its building efficiency division.

Batteries Start-Stop a Market

JCI's Power Solutions group develops batteries and battery systems and represents both the history of the company and one of the keys to its future. On the one hand, stock market analysts want to talk about lead-acid batteries because that's where the current money is made. And the press wants to write about lithium-ion (Li-on) batteries because that's what is being used in plug-in hybrid electric vehicles (PHEV) and electric vehicles (EV). As one executive predicted about consumer purchasing habits over the next five to ten years, "Everyone will talk about electric vehicles, but people will buy hybrids."

Supporting this assertion is a recent JD Power study predicting that in 2015, xEV (a category comprised of hybrid, plug-in hybrid, and electric vehicles) demand will reach 2 million vehicles, with 88 percent of that demand for hybrids, 9 percent for PHEVs and just 3 percent for pure EVs.

But in Europe, a different market is emerging, a market for what is called "start-stop" technology. Start-stop technology enables an engine to shut-off when it doesn't need to run (such as when you're at a stop light), then seamlessly restart when you're ready to go. (Vehicles using this technology have been around for years, often called "light hybrids" in the U.S. The Chevy Silverado Hybrid, introduced in 2007, is just one example.)

By 2015, the predicted European market for stop-start technology is 16 million vehicles, far surpassing the hybrid market. Governments in Europe are encouraging adoption of the technology, which can provide fuel economy improvements of up to 12 percent (along with associated emissions reductions ). The upside for JCI is that start-stop technology can be implemented using current market solutions based upon lead-acid battery technology.

Will start-stop become popular in the U.S. beyond a relatively few vehicle models? Not likely. Studies show that Europeans are more likely to accept the approach given their tolerance toward interior vehicle climate (where many European cars don't even have air conditioning and so wouldn't be affected when the car shuts down, however briefly). The technology also works better with diesel rather than gasoline fueled engines, again favoring the European market.