Cory Ann Wind, Oregon Department of Environmental Quality
With electric vehicles, compressed natural gas and a half-dozen different kinds of biofuels on the market, there are more low-carbon options to choose from. Which ones have the smallest carbon footprint?
Oregon Department of Environmental Quality has ranked them as part of a statewide plan to develop a low-carbon fuel standard – i.e. requirements for fuel suppliers to lower the average carbon footprint of their fuel.
The chart above lists the fuels available in Oregon from the most carbon intensive to the least, tallying the total lifecycle emissions from extracting or growing the fuel to refining it, transporting it, storing it and burning it.
Notice the difference in carbon intensity between corn ethanol made with coal-fired power, corn ethanol made with natural gas-fired power, and cellulosic ethanol made from farmed trees.
At the bottom of the chart, you see biogas CNG (compressed natural gas), which can come from landfills, and yellow grease biodiesel that comes from used cooking oil. In both cases, the lifecycle carbon intensity is drastically reduced because it doesn't count the carbon that went into producing the waste. The assumption is that the waste would be produced regardless of its use as fuel.
The problem with cellulosic ethanol, according to DEQ air quality planner Cory Ann Wind, is that it's not commercially available yet. But that could change as biofuel maker ZeaChem completes its commercial-scale biorefinery in Boardman.
The carbon footprint of fuel is important given the fact that about a third of Oregon's greenhouse gas emissions come from transportation. The ultimate goal of the Clean Fuels program is to reduce the carbon intensity of fuel by 10 percent in 10 years.
The program stems from a controversial bill that passed in the 2009 Legislature, but it's not a reality yet.
The Oregon Environmental Quality Commission is scheduled to vote on the proposed plan next month, which could launch the first phase where fuel suppliers have to report the carbon intensity of the fuels they sell. That will give the state an idea of the overall carbon intensity of the fuel on the market, according to Cory-Ann Wind, air quality planner for DEQ.
The second phase, which would require a 10 percent reduction in the average carbon intensity of fuel within 10 years is more controversial and less certain. It requires additional approvals from the state Legislature and the Environmental Quality Commission. Critics worry the second phase will raise the price of fuel and that there won't be enough supply of low-carbon fuels to meet the regulations.