Bioelectricity More Efficient than Ethanol for Transportation, Study Shows
Vehicles fueled by biomass-fired electricity would travel 81% farther on a given crop and produce fewer greenhouse gas emissions than vehicles powered by ethanol, a new study finds.
In a new study published online yesterday in the journal Science, researchers led by Elliott Campbell of the University of California, Merced modeled entire fuel systems all the way from crop cultivation to vehicle propulsion, comparing cumulative greenhouse-gas emissions for both biofuels and bioelectricity. They found that the bioelectric pathway came out ahead of both corn ethanol and advanced cellulosic ethanol made from switchgrass.
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“We expected that electricity would look better than corn ethanol, but it was surprising to see that this was also the case for the more advanced second-generation ethanols,” Campbell says. “In all cases, the electricity pathway uses a lot less land to achieve the same amount of transportation.”
The study suggests than electric vehicle powered by biomass will travel an average of 81% farther than an internal-combustion vehicle powered by cellulosic ethanol if both are produced from the same area of cropland.
The results also suggest that alternative bioenergy pathways have large differences in how efficiently they use the available land to achieve transportation and climate goals.
>>Listen to an interview with lead author Elliott Campbell from Science Podcast
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Image: Argonne National Laboratory
Steve- My apologies for not including a link to the source, I’ve added one to the reference page at Science, as access is only for paid subscribers.
I’ve also added a link to a short audio interview with the study’s author.
Something more efficient than ethanol? That stuff we continue to subsidize with no return on investment? Color me surprised.
The PDF is behind a subscription firewall. I linked to it here:
http://biodiversivist.blogspot.com/2009/05/electric-cars-get-81-better-miles-per.html
but unless you have a subscription to Science you can’t read it. I did cut and paste a lot from it.
The major difficulty with the study [assuming from the 'crop cultivation to vehicle propulsion does take in all factors, step-up and down transformers, transmission loss] is that coal is still king. Without political pressure, there is no economic incentive for change from coal. Politically, both parties were using the ‘clean coal’ line during elections, which leads to the belief that coal will remain king.
With regionalized plants utilizing regional waste streams [reduce shipping from field to refinery to pump] processing ethanol from waste and THEN combusting the residual biomass for electricity, we can tighten up one end of the IC engine fuel path.
With higher compression engines using hydrous [water added] alcohol base fuels, we tighten up the other end. Total efficiency from feedstock to wheel, just under 40%.
ChuckL, even if the heat is a lot, it’s just added at the time of creation. Changing the gas mixture of the atmosphere does it for the entire lifetime of the compositional changes. Some gasses have lifetimes that are huge (many thousands of years) so the integrated change is what matters.
“well to wheel” efficiencies of electric vehicles is about 2X or greater than compared with ICE (doesn’t really matter what type), so this is the root cause of the benefits of centralized electricity generated power production vs distributed combustion in cars. Centralized production also lends istelf to sequestration and the like to reduce carbon footprints much more cost effectively than doing so on every car that is on the road.
I’m sure the oil companies would love to see liquid biofuels abandoned in favor of bioelectricity. Carbon emissions avoidance is far better achieved by displacing gasoline that power on the grid, if this is realy what we are after. This can be achieved by more efficient combustion engines and yes, the production of affordable electric vehicles, but blending biofuels into gasoline is a much quicker pathway than waiting on the car manufacturers to figure it out and for John Q. Public to step up and voluntarily sacrifice something. We had better get behind biofuels production in the short term or we’ll wake up in another decade with no significant emissions reductions(or reduced dependence on foreign oil).
And before anyone gets too worked up over killing or saving biofuels, coal plant emissions worldwide dwarf this entire segment of the carbon emissions debate.
Don’t lose focus or get too hung up on the propaganda that’s out there, it’s gonna take improvements in many areas to put a dent in this global problem.