Penn State project explores shrubs as renewable energy
STATE COLLEGE, Pa. (AP) — Some people look at the scraggly kind of trees that grow on the side of road and think of them as woody weeds.
At Penn State, there are other people who look at them and see a source of power.
It’s called biomass, a way to use organic material to provide energy without waiting millions of years for today’s plants to become fuel. The idea is sustainability, utilizing resources that will grow again instead of something that gets used up. And the concept itself is recycled since using trees for heat is as old as fire.
But what the NewBio Northeast Woody/Warm-season Biomass Consortium is looking to prove is not just that it will work, but how it will work and to see if it is economically viable in central Pennsylvania. The $10 million, five-year project is funded through a U.S. Department of Agriculture grant.
On the edge of a cornfield just off Interstate 99 between State College and Bellefonte, researchers planted 34 acres of shrub willow in 2012 and sat back to wait. After one early harvest, Armen Kemanian, assistant professor of production systems and modeling, said he and his team waited three years for the plants to grow enough to mow them down.
That time came this month as equipment was brought in from New York, giant harvesters that drove over the 20-foot-tall crop, not only chopping them down but grinding them into chips. Each pass of harvester turned a long row of the skinny trees into a truckload of mulchy mass.
Three years of growth are expected to produce about 800 tons, but that’s one of the things Kemanian says they are measuring. There are other places that grow shrub willow for its biomass potential, like in New York and Canada. The Penn State study is exploring how the native Eurasian crop fares a little more to the south.
“We are working out some of the kinks,” said Michael Jacobson, professor of forest resources and Penn State and Kemanian’s NewBio co-chairman. “The point is, it’s very important to understand the economics. You can’t look at just one harvest and decide if it breaks even or not. There are 15 to 20 years of multiple cycles.”
That is because of how the plant regenerates. The willows planted in 2012 can be regenerated about seven times, giving that one planting a lifespan of decades that it can be harvested. If a farmer or an energy company planted it one time, it could be years before the economic reality of the investment was known.
One saving comes from the hardy nature of the plants. Kemanian says it requires much less maintenance than an agricultural crop like corn or soybeans. That means none of the cost of labor to baby fragile plants.
“Once it’s up, you just harvest it,” said Jacobson. “Now we’ll do nothing. It will just sprout. By August, you’ll probably see it up five feet.”
It will be ready to harvest again in 2019.
There’s also another saving: location. The willow doesn’t need to occupy the valuable real estate that could go to an annual cash crop. Instead, farmers, or other landowners, can use in areas that might be undesirable for other plants because of the terrain or soil itself.