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Cutting edge technology stars in Burbank Landfill Project

Combustion Turbine Specialist Rick Owen with Burbank Water and Power's new 250-kW Ingersoll-Rand microturbine. The unit is the first of its kind to run directly on landfill gas. (Photo by Burbank Water and Power)

A city most commonly associated with the entertainment industry has recently been performing like a superstar in a very different field—landfill-gas powerplants.

The city of Burbank, Calif., installed a 250-kW Ingersoll-Rand microturbine at its landfill in the Verdugo Mountains. The unit, serial no. 1, is the first in the world to run directly off landfill gas. "We went looking for state-of-the-art technology for this expansion," explained Project Manager Rick Owen, BWP combustion turbine specialist.

Initial phase teaches lessons

The joint project of Burbank Water and Power and the city's Public Works Department expands on the groundbreaking Burbank Landfill Project launched in 2001. At the height of the state’s energy crisis, Burbank flipped the switch on 10 Capstone microturbines at the landfill. The 300-kW mini-powerplant was the world’s first commercial microturbine installation to run on landfill gas.

Public Works built the system with funding from the California Energy Commission, and handed it over to BWP to operate. Although research indicated that the turbines would be well suited for the unique application, problems soon arose. "You expect to learn from demonstration projects, and we did," observed Owen. "Public Works didn't realize how wet and dirty landfill gas is or what that was going to do the equipment."

The corrosive gases present in landfill gas ate away at the 10 compressors until they all failed. Investigating the system failure, BWP found that the compressors were not well suited for the application and that the moisture removal system couldn't handle the large amount of water in landfill gas. Also, the activated carbon filtration system placed before the compressors was not cleaning the gas as effectively as the system needed.

Plant adds latest technology

Far from discouraging BWP, "We wanted to use those lessons and advances in the technology to fix the units we had and expand our capacity," explained Owen.

Several system refinements developed after the initial Burbank Landfill Project provided solutions. BWP learned of a sliding vane-type compressor that had operated very well for more than a year at the Los Angeles County Sanitation District’s Calabasas Landfill micro-turbine project.  Filtering the gas both before and after compression and refrigerating the gas to remove moisture would correct the other problems.

The original 10 compressors were replaced with three new compressors, restoring the Capstone microturbines to operation. Adding the experimental Ingersoll-Rand unit boosted the plant's capacity to 550 kW. New centralized controls allow BWP to run the plant from one location and enable system designer SCS Energy to monitor the unit's performance from its central control room.

The IR microturbine operates continuously. "It was designed for 90 percent availability, and it should meet it with no problem," said Owen. "The first time we fired it up, there was one little puff of smoke and it went to full capacity."

The controls monitor the gas pressure from the landfill and turn on the Capstones as needed to burn the excess fuel. The flare that used to burn the landfill gas still runs three days each month to flare off the liquid condensate from the refrigerated gas. Eventually, enough Capstones should be operational to use virtually all the landfill gas and turn the flare into a backup system in case a microturbine goes down.

Experience and accolades

Expanding the powerplant to use more of the landfill gas qualified the project for another CEC grant. The city applied for and received $450,000 toward the total $1.1 million project cost. BWP was able to apply the balance of the funding to its Public Benefits spending obligation. Both the initial installation and the repair and upgrade represent Public Benefits research and development projects.

The Burbank Landfill Project puts the city 550 kW closer to its adopted renewable portfolio standard of 20 percent renewable power by 2017. That incremental step in renewable generation brings a greater leap in experience handling the issues related to integrating diverse resources. For example, the project team had to write testing protocols for the first edition microturbine. "That brought a lot of people together who don't normally get the chance to collaborate," said Owen.

Once the Southern California Air Quality Management Bureau provides written approval of the protocols, BWP will begin testing. In the meantime, the experimental unit will continue to generate clean power under a construction permit.

The upgrade has burnished BWP's standing as a renewable energy innovator. Officials interested in developing similar projects have come from as far away as Dade County, Fla., to tour the site.

Of course, Burbank Water and Power isn't going to all this effort just for the stardom. "It's about environmental stewardship," said Marketing Manager Jeanette Meyer. "The plant disposes of a waste product—landfill gas—by converting it to environmentally friendly electricity."

Even in a town where the main industry is turning dreams into reality, turning that free source of energy into electricity seems like a dream come true. But Burbank Water and Power is clearly ready for the big time.