Mar 7 - McClatchy-Tribune Business News Formerly Knight Ridder/Tribune Business News - David Templeton Pittsburgh Post-Gazette

 

Tidy, efficient electricity production will rule the world's energy future, and Siemens' solid oxide fuel cell is leading the way.

The Churchill company's fuel cell doesn't spew pollutants into the atmosphere, and what carbon dioxide it does produce can be captured and sequestered.

But, best of all, Siemens' system uses fossil fuels -- in particular, coal -- more efficiently than the coal-fired power plants lining the Monongahela and Ohio rivers. Its fuel cell can reach 90-percent efficiency compared with 45 to 55 percent for existing power plants -- almost twice the power from each pound of fuel.

With its parent company Siemens AG based in Germany, Siemens Stationary Fuel Cells plans by 2012 to build a prototype plant in Baden-Wurttemberg, a state in southern Germany, to show off its fuel-cell technology to the world.

Thomas Flower, president of Siemens Stationary Fuel Cells, said the room-sized plant will operate like a large battery that endlessly produces electricity as long as fuel is provided. Separating air and fuel with a permeable membrane allows them to react in a controlled process that directly produces electricity without typical combustion. That means more energy turns into electricity rather than the light and heat wasted by combustion.

The proposed "Energy Baden-Wurttemberg" plant will generate up to 2 1/2 megawatts of power -- enough to power 2,500 homes.

If the technology were used in the Pittsburgh region, as many as 200 fuel-cell plants might be necessary. But each would be a small, unassuming structure that could blend into any neighborhood or community.

With success in Germany and efforts to lower cost, the company would begin mass production of fuel cells for a market anxious for improved technology, which will have global implications in light of the International Panel on Climate Change report that says human-generated greenhouse gases are causing global warming.

As such, Dr. Flower said, the company's fuel cell has "ubiquitous" potential.

"We're not expecting to replace all the power generators with fuel cells," he said. "But could that happen? Yes."

Explaining Siemens' solid oxide fuel cell requires some science.

Siemens' fuel cell initially used a tube with air in its core, but latest advances have replaced the tube with eight triangular, or delta, channels. Each channel features two electrode layers and one electrolyte layer.

In a fuel cell, fuel and air are separated by a thin, permeable membrane called an electrolyte. As air flows through the inner cell channels at elevated temperatures, oxygen becomes negatively charged and works its way through the electrolyte membrane, which boosts the voltage of the cell current. That's another way of saying electrical power is produced.

In addition, on the fuel side of the membrane, the oxygen reacts with the fuel to form steam and carbon dioxide. The high temperature and pressure of the steam and carbon dioxide can be used to power a turbine to produce additional electricity.

The only major byproducts are water and carbon dioxide, which the system can be equipped to capture for sequestration. Dr. Flower said the fuel cell generates electricity in a subdued, controlled manner.

Other advantages include its size -- from the size of refrigerator to a large room. The only noise comes from a blower. By avoiding outright combustion the fuel cell eliminates nitrogen oxide -- the pollutant that causes acid rain.

"It does away with the intermediate steps" of combustion necessary in power plants that burn coal and other carbon-based fuels, Dr. Flower said. Fuel efficiency improves at higher production levels in larger fuel cells.

Yet more energy can be produced by capturing heat the process generates, which can be used to produce hot water or steam, Dr. Flower said. Steam or hot water can be piped to neighboring hotels, hospitals or linen services. If there's no nearby demand, surplus energy could power gas turbines to increase efficiency of the system.

The key, Dr. Flower said, is creating electricity without combustion.

The company has produced fuel-cell prototypes. One, a 5-kilowatt system the size of a refrigerator, was installed late last year in Phipps Conservatory, where it uses natural gas to heat water for tropical plants.

In the meantime, Siemens is busy reducing cost and boosting the size of its fuel cell in preparation for the Baden-Wurttemberg plant project.

With help from the U.S. Department of Energy's National Energy Technology Laboratory in South Park, the company also is focusing on reliability and cost.

"From the DOE perspective, Siemens is a very important player in the complete fuel cell picture," said Wayne Surdoval, NETL's technology manager for fuel cells. "We respect their technology quite a bit. It tends to be mature. They are very experienced in this and have been working on technology a number of years under the DOE."

The DOE is helping develop fuel cell technology in a strategy to cut U.S. reliance on foreign oil. One goal is to use gasified coal to power fuel cells.

"Siemens' fuel cells are pretty reliable," Mr. Surdoval said. "The fuel cell is the most efficient thing to use, and the type of fuel cell that Siemens created is the most efficient of all.

"Fuel cells definitely will play a big part in the energy future," Mr. Surdoval said.