Grass, trees might be next fuel source

The technology to make ethanol out of grass or trees may be several years away, but that doesn’t mean northwestern Wisconsin has to wait to begin developing biomass energy, said Andrew Dane, UW-Extension agent in Chippewa and Barron counties.

Biomass can be used for heating – about three-fourths of the total energy used in Wisconsin is for heating, Dane said. Biomass also can be used to heat boilers, as Xcel Energy is doing to produce electricity at its power plant in Ashland, he said. Xcel is in the process of converting the plant from generating with a combination of coal and wood to all-wood generation.

Two ethanol plants in western Wisconsin are replacing natural gas with corn stover or other biomass to fire their boilers, he said.

“It all comes down to the resources – what we can grow and aggregate and market and distribute,” he said.

Switchgrass, corn stover – what’s left of the corn plant after the corn grain is removed – other crop residues and short-rotation woody plants are things that can be used now for heating, and later for ethanol, when a process is found to make ethanol from cellulose, he said.

Cellulose is a major component of plants and trees.

“We have short-term opportunities to position our region to take advantage of this (ethanol form cellulose) when and if it becomes technologically viable,” he said.

Wood burning is the most familiar form of biomass energy in use. The wood used doesn’t have to be from logs. Wood chips or wood scraps pressed into pellets will work.

Several schools in northern Wisconsin already are heating with wood chips.

The Shell Lake school district is using wood chips and corn.

In Barron an elementary school, high school, community center, nursing home and office of Marshfield Clinic all are heated through a wood-chip-burning system. Now school officials are adding a cooling unit to air condition with wood energy.

There are new wood-pellet-producing plants going into Hayward, Ladysmith and Ashland, Dane said. . . .