Biofuel Bonanza: Willows Grown Diagonally

Algae, sorghum, switchgrass, corn stover, jatropha , camelina … there’s an endless number of biofuel candidates getting lots of attention. But here’s a story about research that goes in a different direction. Literally.

The direction is diagonally: Scientists in the U.K. say they’ve pinpointed the genetic trait that allows some willow trees to produce far more biofuel when they grow at an angle.

image via Imperial College London

image via Imperial College London

Apparently, when this gene kicks in the plant “creates an excess of strengthening sugar molecules in the willows’ stems, which attempt to straighten the plant upwards,” according to Imperial College London, home to the lead researchers in the study.

“We’ve known for some time that environmental stresses can cause trees to naturally develop a slightly modified ‘reaction wood’ and that it can be easier to release sugars from this wood,” said the college’s Nicholas Brereton. “This is an important breakthrough, our study now shows that natural genetic variations are responsible for these differences and this could well be the key to unlocking the future for sustainable bioenergy from willow.”

Willow as a biofuel feedstock hasn’t been a huge focus in the United States, but there is a long-running program at the State University of New York in Syracuse looking into the possibilities.

The university’s Environmental Science and Forestry Department calls  woody biomass “an environmentally sound, locally produced, renewable source of energy and bioproducts,” and its efforts to promote the plant appear to be picking up speed: Just last summer, the U.S. Department of Agriculture announced it would spend up to $4.3 million to encourage planting of the shrub willion in Central and Northern New York.

One advantage the plant can offer – even if it isn’t bending in the wind – is that it can be grown on marginal farmland. This is important in ensuring that the production of biofuel feedstocks doesn’t dislocate food crops.

Back in the U.K., the thinking is that all the willows planted for biofuels production could be bred for the wood-strengthening, high-sugar content.

“We are very excited about these results because they show that some willows respond more to environmental stresses, such as strong winds, by changing the composition of their wood in ways that are useful to us,” said Angela Karp at Rothamsted Research, which participated in the research. “As breeders this is good news because it means we could improve willow by selecting these types from the huge diversity in our collections.”

Pete Danko is a writer and editor based in Portland, Oregon. His work has appeared in Breaking Energy, National Geographic's Energy Blog, The New York Times, San Francisco Chronicle and elsewhere.