“The Tesla’s great technology, but it’s still a niche product,” said Jana Hartline, environmental communications manager for Toyota, who’s riding with me as I head north on the Embarcadero. [...] Toyota, the world’s largest automaker, is convinced that fuel-cell cars better suit the mass market than pure electrics such as Tesla ever will. Toyota insists that fuel-cell vehicles can offer better range at lower prices than battery-powered electrics, although the automaker has yet to reveal the price of its fuel-cell sedan. All that comes out is a dribble of water, the by-product of the fuel cell’s electrochemical reaction between hydrogen stored in two tanks and oxygen sucked in through a slit-like vent beneath the hood. The production model sports a sleek body and broad, bold front highlighted by two big air scoops that feed the cooling system. Toyota has already tested its fuel-cell technology in other cars not offered to the American public, including an SUV that has logged more than 1 million miles of travel since 2007. Jared Farnsworth, senior engineer with Toyota’s fuel-cell program, says he’s tested the cars in weather extremes that include air temperatures down to minus 41 degrees. California has just nine stations now (the Bay Area has one, in Emeryville) although 49 more are under development. [...] the most common way of producing hydrogen involves stripping it from natural gas, a process that releases the greenhouse gas carbon dioxide.