Solid-oxide fuel cells that use gasified coal as a hydrogen source are a good candidate for the power plants of the future, because they can operate cleanly at high efficiencies and large sizes. But among the challenges they face, high manufacturing costs loom large. Now, GE researchers have demonstrated a method for assembling layers of ceramic and metal materials cheaply enough that a solid-oxide fuel cell system can be built for about $800 per kilowatt, which starts to approach the $500 to $550 per kilowatt of a conventional gas-fired plant. GE's six-­kilowatt prototype (left) is a little more than two meters tall, with the fuel cell stack in the top section, and piping and control systems in the cooler lower section. The performance of the prototype suggests that a larger version could lead to gasified-coal-fueled power plants with greater than 50 percent efficiency, much better than the 35 percent efficiency of conventional plants. "I do believe GE has established a new state of the art," says Wayne ­Surdoval, technology manager for fuel cells at the National Energy Technology Laboratory.