Wood Pellets: Today's Choice for Wood Energy

In his overview of wood as fuel and a source of energy from the Encyclopedia of Forest Sciences, Forest Products Laboratory retiree John Zerbe reviews chips and sawdust, shavings, manufactured fireplace logs, and briquettes as sources of wood energy, but here at FPL, we know that wood pellets are the most popular alternative to cordwood for heating.

Fuel-pellet-samples

Zerbe and FPL Natural Resources Specialist Mark Knaebe state that wood pellets are becoming increasingly popular. Pellets are made from processed, ground, debarked logs held together with a binder. When pellets are made from clean wood with little bark, the ash content is low.

Pellets are sold at retail outlets in 40-pound sacks, which handle and store easily. The consumer can purchase pellets in bulk, including in one-ton bags, which can be replenished by a truck delivery. Knaebe says, “Bulk pellets are just like with oil heat: the truck will come and fill your container, and your thermostat tells an auger to feed your boiler or furnace. The pellets should be kept dry to prevent disintegration and to avoid risk of mold and decay.”

“In very large piles of pellets,” warns Knaebe, “you will get a fire about 3 weeks after the pile gets wet because of spontaneous combustion and the high insulating properties of a big pile. This can be prevented with blowers or making smaller piles, never more than 10 feet deep.”

Sometimes pellets for cooking are made from woods with special flavors that can be used in barbecuing, directly or with charcoal or gas, for conveying this flavoring to meat or poultry. Excellent pellet grills are available now. However, the most common use of pellet fuel is for heating with modern and convenient pellet stoves. Some of these stoves have automatic ignition, feed, and control systems. To be EPA certified, they must be 78% efficient. To determine the efficiency of your fuel, you can download FPL’s popular Fuel Value and Power Calculator.

Energy from Wood: An Introduction

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Wood is renewable energy, as this circle indicates.

Brrrr! Here in Madison, Wis., home to the Forest Products Laboratory, we’re having some very cold temperatures. Doesn’t a wood fire sound comforting?

And as nice as a fire sounds in this neck of the woods, what about the use of wood for fuel in other parts of the world? Sifting through the words of wisdom from FPL retiree John Zerbe, let’s delve into his overview of wood as a fuel and source of energy from the Encyclopedia of Forest Sciences.

Zerbe informs us that wood and charcoal are the predominant fuels for heat and food preparation for the majority of citizens in most developing countries. In those countries, wood fuels are also important for powering small- and medium-size industries. Moreover, energy from wood continues to be important in industrial countries.

Wood energy is consumed in a variety of forms that include fireplace lengths, chunkwood, chips, sawdust and shavings, black liquor from pulp manufacture, pellets, fireplace logs, briquettes, charcoal, gasified wood fuel, and liquefied wood fuel. Wood provides warmth and comfort to homes via burning in fireplaces and automated heating systems. And even in industrial countries, wood is used for cooking where it is burned in specially designed stoves for convenience or on grills to bring out special flavors in food.

Wood fuel is important to commercial wood manufacturing facilities where waste wood can be disposed of and used profitably for energy at the same time. Some major considerations in using wood for fuel are environmental impact, economics, convenience, reliability, and simplicity. On balance, wood is an environmentally benign fuel. It tends to be more economic than some other fuels, but may be less convenient, as anybody who has cut and stacked their own firewood knows.

Here at FPL, we love to say “Wood is good.” In future posts, we will go on to discover the many ways wood is good for producing energy.