In February 2012, Greenberry Industrial, Vancouver, Wash., completed the conversion of the Mt. Poso Cogeneration Plant in Bakersfield from a coal-burning facility to one that runs completely on local biomass. The plant will use urban and agricultural wood waste from the San Joaquin Valley agricultural area and clean wood waste and tree trimmings from the Los Angeles area.

The $43-million project brings to the Bakersfield area clean energy, improved air quality, job creation and state-of-the-art technologies for plant control and automation, according to Greenberry Industrial.

The scope includes the construction, fabrication and installation of a biomass unloading, storage, stacking, reclaiming and feed system for the 44-MW facility, jointly owned by the Mt. Poso Cogeneration Co., a partnership of DTE Energy Services and Macpherson Energy, Ann Arbor, Mich.

Tasks included installing truck scales, hoppers, five conveyors from the reclaimer to the day bin, two chain conveyors, four screw conveyors and two rotary valves.

Additional specialty construction work included demolition of existing coal-feed equipment and infrastructure; excavation and fill of nearly 500,000 cu yd of earth to level the fuel-handling area; installation of 3,700 yards of concrete and 150 tons of rebar for equipment foundations; fabrication and erection of 700 tons of structural steel; installation of 7,500 linear feet of service piping and 2,500 linear feet of hydraulic and lubrication tubing; demolition of coal feed equipment and infrastructure; modifications to existing structures and day bins; installation of equipment and instrumentation; and mechanical, electrical and piping tie-ins to the existing facility.

During the 10-month project, Greenberry Industrial says the team met significant challenges, requiring intense coordination. Much of the project involved elevated work in restricted areas with little overhead clearance for crane access, requiring complex heavy rigging. In the boiler tower, for example, the team installed most heavy equipment with rollers, come-alongs and chain falls.

To improve coordination, TJ Cross Engineers designed interconnected plans for the civil grading, structural foundations, mechanical systems for air and water, electrical distribution elements and tie-ins.

"With safety our top priority, daily meetings always addressed the importance of specific preparations and ongoing awareness to maintain safety levels," says Jason Pond, Greenberry Industrial president and CEO.

The project had a compacted schedule, requiring coordination of multiple trades and regular two-to-three-week look-ahead planning. Moreover, most of the conversion work was done while the plant's existing boiler was still operating. Pond says, "There were significant underground wiring and piping components that presented trenches on the job site and the obvious hazards that go with them."

Abnormally wet weather in Kern County intensified already keen safety awareness. The construction team clocked over 100,000 man-hours but lost no time to accidents, with zero recordable incidents. Pond adds, "To me, that's the most important definition of success."

Mt. Poso Cogeneration Conversion Project


Key Players

Owner: Mt Poso Cogeneration Co., Ann Arbor, Mich.

Contractor: Greenberry Industrial, Vancouver, Wash.

Lead Design: TJ Cross Engineers, Bakersfield

Structural/Civil Engineer: TJ Cross Engineers, Bakersfield

MEP: BRUKS Rockwood, Alpharetta, Ga.

Concrete: Toneman Concrete, Lancaster

Drilling: Anderson Drilling, Chino Hills

Electrical: EIU, Metairie, La.

Boiler Modifications: TÜV SÜD Industrial Services, San Diego

Site Work: Turman Construction Co., Bakersfield

Submitted by Greenberry Industrial