Smart Glass, which will be shown off and discussed more fully in about eight weeks, is industrial glass that turns dark in bright sun and becomes clear when it gets dark. By keeping out (or letting in) sunlight selectively, companies can cut their building electricity bills by up to 20 percent because of reduced heating and air conditioning costs, Petraglia said.
Companies such as Hitachi and Leminur will produce the glass, which is coated with a special emulsion, while SPD Control Systems will make the controllers that switch the tint. Another company, Research Frontiers, owns the patents on Smart Glass and licenses the technology to SPD, Hitachi and others.
"Smart Glass changes color from clear to opaque and all shades in between, and in a second or two," Petraglia said during a presentation at the Cleantech Venture Forum taking place here this week. Aircraft corporations are also interested in Smart Glass as a way to increase passenger comfort.
The three-day conference has become one of the major stops for start-ups trying to capitalize on the young but growing interest in. Across town, energy is one of the dominant themes at the Dow Jones VentureOne Summit.
Nearly 140 venture firms areso-called clean-tech investing, according to Nick Parker, chairman of the Cleantech Venture Network, which sponsors the Cleantech Venture Forum. In 2004, more processed silicon got consumed in making solar panels than semiconductors, he added.
"A broader concentration on clean tech will be necessary if we are going to have sustainable societies," he said. "Clean-tech VC is increasingly a substitute for corporate R&D."
A yawning gap remains between the promise of many start-ups and reality. Many of the companies presenting at the Cleantech Forum have achieved a few million in revenue at most, but some assert sales will rise to more than $100 million by 2009. Corporations like Philips and General Electric also make products for energy efficiency.
Still, the enthusiasm is tough to miss. Here are some of the companies and their pitches from the Cleantech Forum so far:
ClearFuels Technology: The vegetable alcohol for ethanol now mostly comes from fermentation. Hawaii's ClearFuels, by contrast, takes ground and dried biomass and turns it into synthetic gas, which is then converted tothat can be mixed with gas. Shell and ExxonMobil want to deploy a similar process to convert for polluted megacities.
"There's enough virgin biomass that you don't need to go to things like municipal waste," which can cost more to process, said ClearFuels CFO Eric Darmstaedter.
The company can turn a ton of biomass into 200 gallons of fuel, better than the 100 gallons of fuel by the conventional methods, according to Darmstaedter. The synthetic gas produced in the process can be used to run the plant. The higher yields mean that the ethanol from the process costs 75 cents to 90 cents, less than the $1.10 cost of a gallon of traditional ethanol.
Extengine Transport Systems: The Fullerton, Calif.-based company produces a unit that attaches to the exhaust system of diesel trucks and buses and converts the nitrogen/oxygen gases in the exhaust that contribute to global warming into nitrogen and water vapor. It does this by mixing in ammonia.
So far, it has sold $1.2 million worth of its Adec I converters and just came out with the Adec II, which plugs in easier. The market is being driven by the fact that many states have begun to impose stricter emission standards and in tandem have offered subsidies for retiring or retrofitting old vehicles. Retrofitting, says Extengine President Philip Roberts, is cheaper.
"Diesel engines last forever," he said.
Ice Energy: Did you ever stick your head into the freezer on a summer day and inhale the cool vapor? That's Ice Energy in a nutshell. The company's Ice Bear 50 system makes ice in large quantities, keeps it in an insulated copper tub, and then delivers the cool air during the hot afternoon hours, when electricity costs the most.
"Fifty percent of peak power is consumed by roof air conditioners," said Ice Energy CEO Frank Ramirez.
Customers who have installed the system, including big-box retailers like Petco, have seen overall energy bills decline by 15 percent, he said. Ramirez, however, did not fully explain how the company could keep away large, established competitors. Revenue over the last 12 months came to $1.75 million, but he said it would grow to $110 million by 2008.