Energy From Trees

Pennsylvania’s forests are rich in potential bio-energy from small-diameter trees that are overcrowded, under-utilized, and inhibit the opportunity for professional management. Recent estimates developed by the Pennsylvania Hardwoods Small Diameter Task Force from the US Forest Service’s most recent Forest Inventory Analysis (FIA) data are that as approximately 658 million tons of wood are held in these "low-use" stems across 17 million acres of forestland in the Commonwealth. Applying well-defined parameters for estimation, the Task Force determined that about one-half of this acreage could be available for harvest; and that, on a tonnage basis, about 468 million tons of wood are not restricted by environmental, regulatory, or ownership restrictions from harvest. Based on this available volume of wood, applying conservative growth rates and making the conversion from green to dry, an annual renewable harvest of six million dry tons of wood per year could be harvested for conversion into various bio-energy sources. For instance, six million dry tons per year is the rough equivalent raw material usage of

600 district energy projects replacing 475 - 500 million gallons of #2 fuel oil annually;
10 wood ethanol plants producing 480-600 million gallons of ethanol per year; or
300 million 40 lb. bags of wood pellets for pellet-burning heaters, enough to heat about 3 million homes each winter in Pennsylvania.

By any measure, there is a lot of energy in those trees!

Other alternative technologies for energy production from wood include wood gasification, wood chemical production, and small-scale wood boilers (etc., for schools, hospitals, etc.). Penn State scientists studied the issue intensively back in the 1970's and 80's, the last time energy prices spiked and caused economic disruption to our country. At that time, they estimated that oil prices would have to reach $70 - $75 per barrel (in current prices) before harvested wood conversion to energy would be feasible. That day seems to be almost upon us, and scientists, engineers, business owners, and elected officials are all considering future options for tapping into our abundant and sustainable forest resource. Recently, the 2006 Goddard Forum held here at Penn State addressed The Pennsylvania Alternative Energy Portfolio Standards Act, and representatives from several alternative energy industries presented the state of their industies' efforts to respond to the changing energy demand created by the act. Included in these presentations were several on the technology and available resource of creating energy from wood.

The Pennsylvania Small-Diameter Hardwoods Task Force, commissioned by the Commonwealth's Secretary of Agriculture, has been exploring various management and utilization alternatives for this resource. The Task Force will produce a document summarizing and prioritizing alternatives in accordance with the various needs of Pennsylvanians. When that report is completed, it will be reported and explained here in the WoodPro TechNotes. Until then, we encourage you to keep an ear tuned to happenings relative to Pennsylvania's Alternative Energy Portfolio - the future is now!

Chuck Ray, Ph.D.

Penn State Wood Operations Specialist

mailto:Cdr14@psu.edu