Better Bioenergy: Rather Than Picking Bioenergy "Winners," Effective Policy Should Let a Lifecycle Analysis Decide
Purdon, Mark, Bailey-Stamler, Stephanie, Samson, Roger, Alternatives Journal
Resource Efficient Agricultural Production Canada (REAP-Canada), a non-profit organization dedicated to an ecological approach to the production of food, fibre and fuel from farms, suggests how the application of full lifecycle performance criteria can make bioenergy competitive with petroleum-based fuels.
BIOENERGY POLICY is often limited to a discussion of liquid biofuels such as corn ethanol and, more recently, second-generation "cellulosic" ethanol. It's time to begin thinking more holistically about developing technologies that capture solar energy efficiently and turn it into useable forms of bioenergy.
Of the $4.3-billion of federal funding for renewable energy available through the Canadian government's ecoACTION program over the next nine years, over 50 per cent is allocated to liquid biofuels such as corn ethanol. But renewable energy can also be produced as green power and solid biofuels. A better plan would reward renewable energies based on their environmental and economic performance. This would allow governments to get out of the business of picking "winners" and allow the best bioenergy options to emerge.
In the absence of an economy-wide policy such as a carbon tax, two incentive strategies could bring down the cost of bioenergy, making it competitive with fossil fuels. The first would see government agree to pay a set price for emission reductions, effectively putting a "bounty" on carbon. A second approach would allocate incentives on a dollar-per-unit-energy basis, varying the level of this incentive based on the relative energy quality of each form of biofuel produced.
But the devil is in the details. Which is the "best" bioenergy option? How much of an incentive for bioenergy do we need? What is the right price for a carbon bounty? Getting objective answers to these questions involves applying four full lifecycle performance criteria, which should be at the core of bioenergy policy in Canada. They include energy return on investment (EROI), greenhouse gas mitigation efficiency, energy cost effectiveness and carbon cost effectiveness.
Resource Efficient Agricultural Production Canada (REAP-Canada)'s research on solid biofuels demonstrates how these four criteria could shape bioenergy policy.
EROI and Greenhouse Gas Mitigation Efficiency
The debate on bioenergy is often discussed in terms of the EROI: the ratio of the amount of energy produced through the bioenergy process in relation to the energy used to make it. Care should be taken to ensure that EROI reflects the full lifecycle of the bioenergy crop, including fertilizing, harvesting and transportation. Corn ethanol has an EROI of about 1.3:1, which means that for every unit of energy put in to making corn ethanol, 1.3 units of bioenergy are produced--a 30-per-cent "return on your investment" in financial terms.
It is possible, however, to produce liquid biofuels from more productive crops such as switchgrass, a perennial species native to Canada's prairies. With the technologies currently proposed for commercial scale-up, switchgrass could be used to produce ethanol with a projected EROI of 4.4 to 6.1:1.
Alternatively, if switchgrass is pressed into pellets or briquettes instead of being used as a feedstock for a liquid biofuel, it can be burned directly for heat energy or in combined heat-and-power systems. This solid biofuel has an EROI of 12.8:1. Using this system, the net energy gain (or renewable energy profit) from a hectare of farmland is nine times higher than a hectare of land used to produce corn ethanol, making this fuel source an option worth considering for creating bioheat in Canada, though its combustion requires appliances that remove particulate emissions.
Though EROI is critical, it's not the only criteria for determining the best bioenergy option. The greenhouse gas mitigation efficiency of different bioenergy options is also important. …