When Ballard Power Systems Inc. first rocketed into public consciousness a decade ago, it had the field of fuel-cell technology largely to itself. No more. Today, at least 50 companies in North America, Europe and Japan are developing fuel cells and related systems and components for the auto industry. They include virtually all of the major automobile manufacturers, as well as companies such as Hydrogenics Corp., United Technologies Corp., and Nuvera Fuel Cells Inc., which have relationships with other car makers. Together, these companies are spending in excess of $2-billion (U.S.) annually on fuel-cell research and development, an industry official said.