In LCA, inputs are uncertain. Processes are unknown. Targets move, constantly. Yesterday’s data can become irrelevant tomorrow.
According to scientists Arpad Horvath and Tom McKone of the Energy Biosciences Institute in Berkeley, biofuel LCA attempts to predict the unpredictable.
Three years into their research program on the topic, they haven’t resolved the dilemma, but they are narrowing the boundaries on the risks and challenges.
“We built more specificity into our program,” says Horvath, a UC Berkeley professor and expert on environmental analysis. “We’ve spent three years mining massive amounts of data and enormous resources, drilling down to find the information that is most useful to what we (in the EBI) are doing.”
Using their resulting computer model, they take scenarios carefully crafted by EBI bioenergy analysts Caroline Taylor and Heather Youngs and then plug the relevant data—more than 20 different criteria—into the program. Then the tool walks through every life cycle state, starting with biomass production, then biorefining, distribution and storage, and transportation.
“The analysis is done at the county level,” says McKone, a health risk assessment expert at Lawrence Berkeley National Laboratory. “We try to figure out the exact location of production, refining and use. After all, most of the impacts are local—carbon, health, and water are the Big Three.” Eventually, they’d like to be able to project biofuel impacts for all 3,109 counties in the United States, and then internationally.
The first test scenario is based on Miscanthus, a tall, fast-growing grass, as the source biomass, and an enzyme-based cellulose deconstruction and bioprocessing technology that is prospective but promising. As varying feedstocks and technologies emerge, their values can be plugged into the tool and impact estimates given for their full life cycles, information that will help decision-makers in their quest to develop sustainable, environmentally responsible biofuels.