Nationwide, the overwhelming majority of biomass power plants proposed around the country plan on using forest wood as fuel
. In the world of cellulosic ethanol production, however, a greater variety of feedstocks are utilized, including corn stover, the dried plant material left on the field after the corn harvest. As with fuel harvesting for biomass power, cellulosic ethanol feedstock collection is heavily dependent on subsidies like the Biomass Crop Assistance Program, which is likely to be at least partially defunded in the Senate following a vote for its defunding in the House Appropriations Committee
From the article, we learn: Producing 25 million gallons of ethanol at the as-yet-unbuilt $250 million POET ethanol plant will require more than 300,000 tons of corn stover. But,
“Farmers won't give the stover away. Not only is there the time, labor and equipment needed to harvest and bale it, but it also is valuable in maintaining soil fertility and protecting the ground from erosion.
In areas where there is little risk of erosion, farmers could harvest one to two tons of stover an acre without creating environmental issues, according to USDA research”
Let’s assume that it’s realistic to harvest 1.5 tons per acre. That means it will require 200,000 acres of corn stover to provide feedstock for this one ethanol facility, part of POET’s “Project Liberty
” (tagline: “Cellulosic Ethanol by POET. For America”). That’s 312.5 square miles. Of Corn Stalks.
The Des Moines Register article informs us that in all, farmers are getting $80 – $85 a ton for selling corn stover to POET. The BCAP subsidy has been giving biomass producers $45 per dry ton
, which works out to be around $35 per ton at typical moisture content for stover. Part of that money reimburses farmers for the extra fertilizer that they need to apply after removing the stover from fields:
"Farmers who harvest some of that will have to apply extra fertilizer to their fields to replace nutrients removed with the crop material, primarily potassium and phosphorus but also some nitrogen.
That additional fertilizer will cost about $15 to $20 an acre, said Douglas Karlen, a USDA soil scientist in Ames who has studied the impact of harvesting stover on soil fertility."
And those economics all play out before the approximately $5 billion a year that ethanol gets in subsidies for sales at the pump – arguably one of the most wasteful and environmentally harmful federal subsidies that exists. Stay tuned
for further efforts to defund that program.
Biomass power generators and biofuels producers are all looking to the same feedstocks. The economics of corn stover collection for biofuels apply to its use as a fuel at combustion-based power facilities. Renewable fuels and power that rely on ongoing subsidies for fuel delivery are a poor substitute for renewable energy where the fuel is delivered for free
– like wind and solar.