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Biomass: Energy of the Future?

On a recent Tuesday evening, residents of Scottsburg, Indiana gathered in the plain white sanctuary of the First Southern Baptist Church—not to worship, but to protest.

“We don’t need another burner that will put out more carbon dioxide and particulate matters than coal in our area.”

This is Pat Berna.  She’s a nurse practitioner who has been organizing opposition to the biomass plants.  They worry the new plants will spew more pollution than coal-fired plants. Biomass is basically organic fuel: anything from wood chips, to switchgrass, to the leftovers from agricultural production.  It’s either burned or turned into a gas to create steam, which then turns a turbine to make electricity.  A pretty old technology in some ways, although the Scottsburg and Milltown plants will use a newer, more efficient method.  Still, Berna says it’s not enough.

“We’ve looked at what they’re going to burn, and the regulations and the filtering just are not sufficient, nor will they adapt the better technologies,” says Berna.

She couldn’t say what those better technologies are, although she and other opponents cite a list of other problems they believe the plants will cause–including airborne soot and dust, increased traffic, and odor.  The plants’ developer, Liberty Green Renewables, says may of these claims are false.  But they weren’t allowed to respond at the meeting.  So I met Liberty Green partner Terry Naulty on the porch of a restaurant around the corner. I asked him what he made of so much vigorous opposition.

“I think it’s a combination of not in my backyard and a general misunderstanding of the technology.”

Naulty says one misunderstanding is about what the fuel really is.  It won’t be cut from trees in virgin forests, or grown on land that could be harnessed to produce food.

“Well, this area of southern Indiana is actually a highly productive forest products industry.  And we have a lot of sawmills, a lot of furniture manufacturing, and the waste products that come from those operations is what we use as fuel,” Naulty says.

Available biomass resources in the U.S.. Image courtesy NREL.
Available biomass resources in the U.S.. Image courtesy NREL.

But just because it’s renewable, is it cleaner?  The Environmental Protection Agency says biomass produces considerably fewer pollutants than coal.  There’s much lower toxic mercury and acid rain-causing sulfur dioxide.  And its global warming-producing carbon dioxide emissions are considered nominal.

Richard Bain is an engineer with the National Renewable Energy Lab’s bioenergy center.  He says the biggest concerns with biomass plants built close to communities he’s studied are often the increased traffic and the potential odor of stored wood, if it gets wet. Liberty Green has proposed widening roods to handle that traffic and says it should be able to contain any odors on site.  But residents have one more concern: that the plant will release toxics into the water it uses to cool the boiler and then discharges.  Richard Bain says that won’t happen.

“If you’re using it either for irrigation purposes or putting it into a municipal water treatment system, it should have no negative environmental impact.”

Those are the two methods Liberty Green has elected to handle their waste water. They say the water never touches any of the fuel. It circulates through metal tubes several times and is then released. In Scottburg, it will go into the wastewater treatment system.  In Milltown, it will irrigate a field of switchgrass, which the company will also use for fuel onsite.  So, while opponents continue to fight them, environmental permits for the plants are pending.  And interest in biomass is picking up elsewhere, including in Kentucky, where some of the Governor’s top advisors believe biomass will be the most abundantly available renewable energy source for the future.

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Agriculture Could Play Key Role in KY Energy Future

Agricultural and forestry leaders came together in Louisville this week to determine how their operations could help control the state’s greenhouse gas emissions as well as how they might contribute to Kentucky’s renewable energy goals.  The University of Louisville’s Kentucky Renewable Energy Consortium organized the forum.  And Consortium spokesman Cam Metcalf says participants realized the magnitude of the state’s energy needs.

“I think the reality that became very clear is that we’re going to have move 25 million tons a year of these energy crops through collection and processing in an economically viable way so that we get the energy out of them,” says Metcalf.

Kentucky has adopted the goal of getting 25 percent of the energy it uses from renewable sources by 2025.  Metcalf says the challenge will be to make energy crops like switchgrass and miscanthus, which can be turned into fuel, attractive for traditional farmers.

At the forum, KREC also awarded its second round of grants for energy efficiency and renewable energy research.  Metcalf says these fields of research are becoming increasingly popular and more competitive in Kentucky.  Metcalf says that in the Consortium’s first round of funding, they considered 14 applications from two universities.

“This time, we have 866 thousand dollars.  We had 29 proposals from 6 universities and were able to fund seven projects,” Metcalf says.

The projects range from enhancing a solar heating pipe at the University of Louisville to building a weather-controlled demonstration house at the University of Kentucky.

Environment In-Depth News

Biomass: Kentucky's Best Bet for Renewables?

NOTE: Two corrections have been made to this transcript. One involves the megawatts produced by EKPC’s landfill gas plant in Hardin County. The other involves the energy potential of a pound of switchgrass. Thanks to employees of Eastern Kentucky Power Cooperative for catching the errors. – K.E.

Biomass is organic plant or animal matter, and even household garbage, that can be used to generate energy. Everything from saw dust to corn cobs, from animal manure to landfill gas can be turned into electricity. Biomass is attractive because it’s when it’s used to produce electricity, it’s low on greenhouse gases—which contribute to global warming. But just a handful of utilities in Kentucky have started down the biomass road. And one of those has headed for the dumps.

At the Hardin County landfill, Eastern Kentucky Power Cooperative’s Ralph Tyree stops his truck at a dirt-covered section of dump. He points to some metal pipes sticking out of it.

“Those are the gas collection wells at this site. We have a total of about 24 of them. And they’re tied together in a common system,” Tyree says.

The wells go deep into the layers of compacted household garbage, which has been stewing in the landfill.

“Basically you’ve got the bacteria that’s feeding upon this waste.”

And in the process, that hungry army of bacteria digests the waste and produces a gas called methane. And methane can be burned to produce electricity. Pipes carry the gas to a generating plant down the hill.

“We’re inside the Hardin County landfill gas plant. This is about a 5500 square foot facility,” Tyree says.

Behind two panels of glass three giant yellow engines are chugging along, combusting the methane.

“You’re firing this engine with it, and that generator is direct coupled to that. And it’s producing the electricity at this plant. “

Tyree says the plant generates about two and a half megawatts of power — enough to power about 1400 homes. It’s capable of producing two or three times that. But Tyree says the amount of gas predicted to come from this landfill –even as it grows—will still be less than 10 megawatts. With the amount of garbage Americans generate each year, you’d think that firing up every landfill could solve our energy dilemma. But Tyree says that even if every Kentucky landfill were tapped, they wouldn’t generate nearly enough power on their own to meet statewide demand.

But other kinds of biomass could one day help meet that demand on a large scale. For example, switchgrass. It’s a tall, native prairie grass that can be cultivated. A hundred acres of switchgrass could produce 750 megawatts over the course of a year. The University of Kentucky’s Tom Keene says the grass is well suited to Kentucky’s climate—and it’s got a range of uses.

“We know that we have the soils, the fertility, the climate to grow it. We can burn it, we can make ethanol out of it,” Keene says.

But Keene says it can be a tough sell for farmers. The grass takes about three years to mature before you can harvest it. Still, he’s managed to convince enough farmers to start 100 acres on plots throughout the state.
“Here in Kentucky we’ve just done very little to explore alternative energy sources. And this project was an endeavor to start that if you will, to get the ball rolling, by getting switchgrass established in some areas of eastern Kentucky, primarily in an area that’s been hard hit by the loss of the tobacco quotas we had,” says Keene.

Once Keene’s plots mature, he estimates they’ll produce about 5 tons of switchgrass. Energy Information Administration biomass expert Bob Smith says large scale switchgrass use faces two hurdles on the production side.

“You have the actual cultivation, and then you have the harvesting, transport, storage issue.”

In other words, the infrastructure isn’t yet in place to handle large amounts of switchgrass. Another hurdle is the technology to produce energy from the grass. Smith says it can be combusted, but there are few biomass generators in the U.S., and those few are relatively small. The more efficient technology would be gasificiation, in which biomass is heated and turned into gas. Bob Smith says it’s also better suited for large plants.

“However, that technology is probably about 10 to 15 years out, and it’s largely untested.”

Smith says getting investors to embrace what’s untested will not be easy. And in the current climate, biomass for transportation fuels is getting a lot more of the spotlight than biomass for electricity.

Power lines take electricity from the landfill to Hardin County residents