Dow Chemical Co. and General Motors Corp. (GM), two giants in their sectors, are partnering on tests of the feasibility of using fuel cells to power manufacturing plants. Expected to begin in the fourth quarter of this year, the tests will involve placing GM fuel cells at Dow's largest manufacturing site in Freeport, Texas. The fuel cells will use hydrogen created at the plant. If tests go according to plans, Dow could eventually use up to 35 megawatts of power generated by 500 GM fuel cell units on an ongoing basis, enough power to run 25,000 homes for a year. According to GM, this is 15 times larger than any other known fuel cell transaction. If tests proceed as planned, Dow will become the largest fuel cell user in the world. "Technology moves forward in steps. This step can prove the feasibility of manufacturing and using fuel cells in significant quantities," says Bill Jewell, Dow's business vice president of energy. The tests are planned through 2005, with plans to commercialize the technology in starting in 2006. The two companies are considering using the technology at other Dow sites as well.