Providing Electricity With Discarded Christmas Trees and the Freres Cogeneration Power Plant

January 28, 2016

The holidays are over and once again Freres Lumber Company has partnered with Cub Scout Pack 50 to recycle Christmas trees for families throughout the Santiam region. This is a partnership we have enjoyed for over 5 years, which provides a valuable service to many people in our community who have a difficult time disposing of these last vestiges of the holiday season. Most of the trees would likely have been tossed onto a burn pile or cut up and dumped in yard waste bins, rather than being used to generate electricity through our cogeneration power plant.

Recycling these trees for power generation provides a valuable renewable resource, however, this source of fuel is seasonal and an extremely small percentage of the fuel our 10 Megawatt facility uses each year. Generally speaking, you can assume:

10 Bone Dry Tons of Fuel = 100,000 lbs steam/hour = 10 MW hours of electricity

While this simplifies the math in regards to biomass power generation, it is not entirely correct since any process is not 100% efficient and a portion of the heat is used to run the facility, rather than generating steam for the turbine. This is called the parasitic load. In addition, our facility is a true cogeneration facility, in that we have a variety of uses for steam throughout our plant processes which reduces the amount of electricity our facility can produce, such as block conditioning prior to our veneer lathe and veneer drying.

The Freres plant supplies 40% of the fuel to our biomass facility through our primary veneer production process, and the remainder is supplied through long-term relationships with local fuel suppliers. These suppliers are typically companies who provide drop boxes to local business that develop wood debris, wood waste collection facilities, or even local landowners who are clearing agricultural ground. Contrary to what some may have heard, whole trees are not harvested for biomass power generation. There are higher value uses for logs, such as lumber, veneer, or chips, and ample supplies of lower-value biomass. Some more general factors:

1 52ft Possum-Belly load of fuel = 30 Green Tons of Fuel (50% MC) = 15 Bone Dry Tons of fuel

When we purchase fuel we always purchase on a Bone Dry Ton because the moisture in the wood diminishes the amount of usable energy. Assuming 8,000 hours of operation, and the above factors, we need to purchase between 8 and 9 truckloads per day to keep our facility running!

The Freres Lumber Company cogeneration facility assists in the recycling efforts of local businesses and municipalities, supports truck drivers hauling the biomass, employs ten full time workers to run the facility, and initiates commerce with businesses selling supplies and equipment to keep our plant running. In addition to these advantages, recycling wood that would otherwise end up on a burn pile or landfill provides many social and environmental benefits to everyone in our community, all while producing enough electricity to supply power to about 5,000 households throughout the Santiam Canyon!

Not bad for a day’s work.