Cellulosic ethanol ranks dead last
Mark Jacobson (associate professor of civil and environmental engineering, Stanford University) has just published a paper in the journal of the Royal Society of Chemistry. You can read the entire article here (PDF).
BEV = battery electric vehicle
HFCV = hydrogen fuel cell vehicle
CSP = concentrated solar panels
PV = photovoltaic
CCS = carbon capture and sequestration
The expense of creating a hydrogen distribution grid would kill HFCV. Costs are not a part of this analysis. Biofuels might be fairly inexpensive. The problem is that as a cure they are worse than the disease:
Wind-BEVs ranked first in seven out of 11 categories, including the two most important, mortality and climate damage reduction. Although HFCVs are much less efficient than BEVs, wind-HFCVs are still very clean and were ranked second among all combinations.
The Tier-4 combinations (cellulosic- and corn-E85) were ranked lowest overall and with respect to climate, air pollution, land use, wildlife damage, and chemical waste. Cellulosic-E85 ranked lower than corn-E85 overall, primarily due to its potentially larger land footprint based on new data and its higher upstream air pollution emissions than corn-E85.
In sum, the use of wind, CSP, geothermal, tidal, solar, wave, and hydroelectric to provide electricity for BEVs and HFCVs result in the most benefit and least impact among the options considered. Coal-CCS and nuclear provide less benefit with greater negative impacts. The biofuel options provide no certain benefit and result in significant negative impacts. Because sufficient clean natural resources (e.g., wind, sunlight, hot water, ocean energy, gravitational energy) exists to power all energy for the world, the results here suggest that the diversion of attention to the less efficient or non-efficient options represents an opportunity cost that delays solutions to climate and air pollution health problems.
Here is an article that does a good job ripping CCS to shreds (hat tip KO).
Here is a blog article that is critical of the low rank given to nuclear power. They have a reasonable beef about old data used, and don’t care for the speculative nature of nuclear proliferation. They glossed over the study assumption that it will take decades to get a significant number of nuclear power plants up and running, thus allowing coal fired power plants to spew CO2 for a few more decades.
I’m sure the biofuel proponents will weigh in soon enough.