How America's Greenest Cities Got Green

Case Study: Oakland's Zero Emission Bus

The East Bay cuts pollution with hydrogen-powered transit

The buses are 40-foot-long behemoths, but they glide along downtown streets as silently as sleds coasting over snow; passersby barely turn their heads. The local AC Transit agency, which serves Oakland, Berkeley and other East Bay cities, hopes its fleet of three hydrogen-powered buses—the largest in the nation—will help to leave the environment just as undisturbed.

Jaimie Levin, AC Transit’s director of alternative-fuels policy, had his conversion experience in 1999 when he attended a demonstration. “I couldn’t believe the potential for addressing environmental-health issues,” he says. “The only emission from this bus was water vapor.” When the California Air Resources Board passed a regulation in 2000 requiring transit agencies to switch to cleaner buses, AC Transit had the impetus it needed to start a project. Over the next few years, it amassed more than $12 million in grants and forged partnerships with multiple companies that helped them design the hydrogen-powered buses. The first buses took to the streets in 2005, and the fleet should grow to eight in 2009.

Although the buses substantially reduce transit pollution (diesel buses emit 130 tons of carbon dioxide per year), initiatives like AC Transit’s remain largely showcase projects. Custom components drive the price of each bus to $2 million, more than five times the cost of diesel buses. Levin believes this will change if U.S. authorities throw their full political and financial weight behind hydrogen—which seems a more feasible goal now that the Federal Transit Administration has started parceling out $49 million in research grants for fuel-cell buses. “Ultimately, this becomes a public-policy decision,” he says. “We can bring costs down by building the buses on a large scale, and local governments can help accelerate that.”

Case Study: Make Power, Save the Heat

Chicago produces twice the energy with a third the carbon

A typical fuel-burning power plant is wasteful in two ways: It produces harmful emissions, and it squanders two thirds of the energy it generates. The primary reason? Heat, the natural by-product of fuel combustion, dissipates into the atmosphere unused.

Chicago is among the first cities to confront energy loss head-on. The city government has invested in cogeneration, the simultaneous production of heat and electricity, which is twice as efficient as conventional fuel-burning power production. The strategy is also a potent means of reducing greenhouse-gas emissions. A cogeneration plant produces only one third the CO2 of a coal-fired power plant. In its most recent energy plan, Chicago committed to producing 1.5 billion kilowatt-hours of electricity from cogeneration by 2010—25 percent of the city’s increased energy needs from 2000 to 2010.

Rather than allowing accumulated heat to escape through exhaust vents, a cogeneration facility collects the hot steam exhaust produced by natural gas combustion and channels it into a network of pipes that distributes it throughout the building. “You can take steam and use it directly for heating the building, cooking, and hot water,” says John Kelly of Illinois-based Endurant Energy. “That’s huge.” Chicago’s famed Museum of Science and Industry developed a cogeneration plant in 2003, and in recent years other city institutions, such as the Jesse Brown VA Medical Center, have followed suit. Kelly thinks the cogeneration meme will soon spread. “Manhattan is anticipating a power shortfall of 1,000 megawatts,” he points out. “It’s a perfect candidate.”

HOW IT WORKS

Cogeneration starts when a generator burns natural gas [A] to produce electricity. The hot exhaust from that combustion boils water [B], and that steam powers a turbine [C] connected to a second generator [D], producing another shot of electricity. Any leftover waste steam heats the building.