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Growing interest in growing fuels

NRRI helps map out energy potential across the U.S.

U.S. map of average annual poplar potential

Thanks to NRRI’s decades of work breeding tree species in the greenhouse, the United States will be ready with fast-growing energy crops to fuel alternative energy resources. NRRI’s Populus deltoides species and other hybrids are in the line-up with sorghum, switchgrass, willow, energy cane and others that are being tested for conversion to biofuels for alternatives to gasoline and diesel fuel.

But just how much can we expect to grow and harvest across the U.S.? NRRI’s Bill Berguson is the best person in the country to help answer that question. As leader of the Department of Energy’s Woody Energy Crops Team, and with 25 years of experience as NRRI Forestry Program Director, Berguson was asked to sort out what role the fast-growing hybrid poplar could play in the energy crops arena.

NRRI has invested almost 20 years of research into generating fast-growing trees by cross-breeding various species of poplar from around the world to select new, fast-growing biomass hybrids.

"What is emerging is an invaluable stock of genetic material that is becoming utilized worldwide as capabilities and knowledge develops further," said NRRI Director Rolf Weberg. "This program is a gem for alternative fuel possibilities."

Berguson coordinated the national dataset and developed tools to standardize the national biomass yield data for use in the large-scale mapping effort. Then, working with Oregon State University, his long-term poplar data was incorporated into a national map that shows where poplar and other crops can be grown and what yield can be expected with current technologies.

"The energy markets are so huge that they could use up any conceivable naturally occurring or easily obtainable resource," Berguson explained. "If the economics of biofuels prove to be competitive with more traditional fuels, eventually we have to grow it."

Dedicated energy crops will be more expensive than what is currently available as excess wood and harvest slash. But crops — especially fast-growing and dense crops, like hybrid poplar — are much more controllable and predictable, which is very important.

As part of the overall Regional Biomass Partnership, NRRI is one of several universities developing a sustainable supply of biomass feedstock and has been instrumental in growing hybrid trees across the U.S.

The mapping project was an outgrowth of the 2005 Department of Energy’s Billion Ton report which set out to estimate "potential" biomass nationally — forest, agricultural and energy crop resources — available for conversion to fuel. NRRI played a key role in updating the report in 2011 to incorporate more rigorous methods. The report projects that the U.S. could have between 1.1 and 1.6 billion tons of available, sustainable biomass for energy use by 2030. The report’s lead organization is the Oakridge National Laboratory in Tennessee.

"We wanted to go wall-to-wall, get a nationwide prospective of these crops, understand their potential productivity, growing range, resistance in temperature extremes..." said Laurence Eaton, Natural Resource Economist at Oakridge. "We hope the map is used strategically for planners and policymakers to identify where there is significant yield potential to do targeted investments."

The next steps are to fully test and optimize ways to make the biofuels. Meanwhile, the maps will be continually updated with new and better data inputs to develop more clear information about the resources. Bio-based liquid fuels are starting to become reality through private sector efforts of companies like POET in South Dakota and DuPont Danisco Cellulosic Ethanol, LLC, in Iowa.

"Many of the crops haven’t been grown for a long time in the U.S.," Eaton added. "The hybrid poplar is still developing... this is just the beginning."

NRRI’s hybrid poplars hop the big pond

In Europe, where energy costs are more than double what is paid in the U.S., there’s much more keen interest in alternative energy resources — especially to generate electricity and to replace natural gas for heating.

That means there’s a keen interest from across the pond in NRRI’s hybrid poplars. The National Insitute of Forest Research in Hanover, Germany, contacted NRRI to get some of the fast-growing tree material to start their own nursery. NRRI’s forestry program was happy to share.

"There’s more political will to reduce greenhouse gases in Europe," explained Forestry Program Director Bill Berguson. "And their energy costs are astronomical compared to the U.S. They pay almost three times more for electricity, and natural gas for heat is terribly high there, too. That’s why they’re testing all the genetic material they can find to convert to renewable fuels in Europe."

The process has taken two years, but NRRI’s hybrid poplars are now growing well — and fast — in Europe to help those countries develop biomass fuel production.