Gary Hirshberg, CEO of Stonyfield Yogurts, spoke about his company and its commitment to "green" technologies.

The Providence Journal Bob Breidenbach

SOUTH KINGSTOWN — “When you shop, you’re voting,” yogurt tycoon Gary Hirshberg told an energy-conscious audience at the University of Rhode Island’s Ryan Center yesterday.

The author of Stirring It Up: How to Make Money and Save the World, told participants at the 2008 Energy Solutions Expo that his Stonyfield Farm has become the most profitable of the top three producers of yogurt worldwide by its devotion to sustainability.

But the company has still not done enough to eliminate waste, Hirshberg said.

“The ultimate solution is when you’re finished eating the yogurt, you’ll eat the cup,” he said.

“Waste is a myth, as is the place called ‘away’ is a myth.” He said when he was looking at how to treat his yogurt plant’s biological waste, along with water used to clean the food-grade tanks, he learned that wastewater is usually treated by adding water and oxygen, agitating the mix, then pumping it somewhere else.

“Every one of those steps takes energy,” he said. At Stonyfield, the waste is subjected to an anaerobic process that produces a fuel that can be burned to power the plant. The equipment, which he said cost a half-million dollars more than a more conventional system, paid for itself in the first nine months.

“I’ve taken a cost center and turned it into a profit center.”

He said that when Stonyfield started as a seven-cow company in New Hampshire, in 1983, “no venture capitalists wanted to talk to a couple of guys who were talking about organic yogurt.

“Now I talk about the profit of it, and everybody’s listening.”

He predicted “massive economic opportunity” in a marketplace that uses less packaging, invests in “negawatts,” (the energy you’re not using) and supplies products that will help consumers save energy as fuel costs rise.

Even as he spoke, the roar on the exhibition floor behind the audience testified to the enthusiasm of buyers and sellers discussing products in a marketplace that values energy savings. Suppliers demonstrated the insulating qualities of their materials, nonprofit organizations advocated for behavior changes as simple as turning off lights or using compact fluorescent bulbs, and merchants explained the advantages of their solar, wind or biodiesel systems.

Organizers estimated the turnout at about 1,000 people. There were about 80 exhibitors.

Nodding toward a Toyota Prius on display near the stage, Hirshberg said that even if everyone drives a hybrid car and works hard to dramatically reduce the nation’s carbon emissions, by the middle of this century the climate of New Hampshire will resemble that of current-day Rhode Island; by 2100, he said, New Hampshire will be as warm as northern Virginia.

A map near the entrance showed that if the sea level rose six meters from global warming, Providence would lose half the Providence Place mall, the entire financial district, The Dunk, 111 alcohol establishments, 250 petroleum tanks, the Fields Point wastewater treatment plant and the footings of the new section of Route 195.

Despite those dire scenarios, Hirshberg called the future “immensely, immensely bright.” With scientists focusing on biomimicry — the study of nature for efficient systems and structures — and with “green” companies enjoying profits and brand loyalty, he said, people like those in the audience and at similar events across the country are making changes.

“We only have one of these,” Hirshberg said as a slide of planet Earth filled the screen behind him.

“We have the power,” he said. “You’re exerting that power by coming here today. You’re exerting that power when you go out of here and shop. ... If you want less packaging, that’s what’s coming to be.

“Not only can we change our habits, but we can create more profits as well.”

dnaylor@projo.com