So far, it's profitable for farmers. The co-op can pay $90 to $100 per ton while CVEC estimates it costs a farmer $66 per ton, or $33 per acre, to harvest and deliver them.

CVEC's cob price is supported by a USDA Farm Service Agency initiative to help biomass markets get established. The Biomass Crop Assistance Program matches the payment CVEC gives cob producers, up to $45 per dry ton. CVEC announced in October they were one of Minnesota's first facilities to qualify for the program. BCAP's matching payments last two years.

Local growers collect cobs with special equipment. One type of cob harvester uses a wagon pulled behind the combine. Another type keeps grain separated from cobs in a hopper on top of the combine. Either way, their designs don't require a farmer to make extra passes down the field. Cobs are collected before they even hit the ground, so CVEC doesn't have to worry about dirt and debris.

CVEC has seven cob harvesters that have been leased by five farmers this year, Zurn said.

This is the second year CVEC is taking cobs. In 2008, growers collected approximately 1,500 tons from 3,200 acres.

The plant's work with cobs has been supported with grants from multiple groups, including the Minnesota Office of Energy Security, Minnesota Corn Research and Promotion Council and the university's Initiative for Renewable Energy and the Environment.

The co-op held three demonstration days last year and created a promotional video to get grassroots support for using cobs. The university's West Central Research and Outreach Center in Morris conducted a feasibility study.