Santa Barbara to pull plug on fuel cell at treatment plant

With its efficiency declining, the fuel cell at Santa Barbara's El Estero Wastewater Plant is likely to be replaced with a more reliable internal combustion generator.

The Public Works Department will recommend at today's Santa Barbara City Council meeting that the city terminate its current Power Purchase Agreement with Alliance Monterey, LLC. after several attempts to fix the efficiency issues failed.

The fuel cell, which produces electricity by converting methane into electrical current, was installed in 2004 to improve the energy efficiency of the wastewater plant.

The plant, which is the city’s biggest consumer of electricity, generates enough methane to provide approximately 500 kilowatts of electricity—enough to provide about half of the plant’s electricity needs. The city agreed to let Alliance Monterey install the fuel cell at the company’s expense in exchange for selling the city electricity from the cell at a discount from what the city would normally pay the utility.

“It was a really good idea,” Jim Dewey, energy manager for the City of Santa Barbara, said. “But it was really kind of a pilot project experiment to see if fuel cells could really work with this kind of gas.”

Fuel cell technology had not yet been widely tested in a real production plant but the cell seemed to work initially. As time went by, however, the efficiency began to drop.

Tests showed that the chemical composition of the gas being produced by the wastewater plant contained impurities that eroded the function of the cell.

Attempts were made to compensate, but a type of sulfur in the gas proved too difficult to eliminate due to the low concentration needed to corrode parts of cell.

“To clean up a component like this at the parts-per-billion level is very difficult,” Dewey said. “And I don’t think they fully understood what could happen with that.”

Efficiency dropped to nearly 5% of its total capacity and it was decided that the fuel cell needed to be replaced.

The fuel cell wasn’t considered a total failure.

“The city didn’t put up any money, so the city’s not out of anything,” Dewey said. “We’ve learned a lot of things from the process like how much gas was produced, the quality of gas, and we can move forward at this point with a lot more knowledge...it wasn’t a wasted effort.”

And methane internal combustion units, which generate electricity by rotating a turbine with combustion force, have a proven track record in waste management facilities.

“It’s a technology that’s been in use at wastewater facilities for years,” Dewey said. “So we feel good about the project.”

City Council member Dale Francisco agrees.

“No matter what the technology you use,” he said, "being able to generate electricity onsite for the city’s single largest electricity user from gas that would otherwise just be burned off, that’s a big win.”

Das Williams also believes it illustrates the value of advancing renewable energy.

“We’ve made huge strides in the last few years,” he said. “And created a lot of jobs by investing in alternative energy and saved a lot of money.”

Source: NICK C. TONKIN, TheDailySound.com