by Graeme » Fri 03 Jul 2015, 23:30:34
Study: even with high LDV electrification, low-carbon biofuels will be necessary to meet 80% GHG reduction target; “daunting” policy implications
$this->bbcode_second_pass_quote('', 'A') study by researchers from the University of Wisconsin-Madison and a Michigan State University colleague has concluded that even with a relatively high rate of electrification of the US light-duty fleet (40% of vehicle miles traveled and 26% by fuel), an 80% reduction in greenhouse gases by 2050 relative to 1990 can only be achieved with significant quantities of low-carbon liquid fuel. The paper is published in the ACS journal Environmental Science & Technology.
For the study, the researchers benchmarked 27 scenarios against a 50% petroleum-reduction target and an 80% GHG-reduction target. They found that with high rates of electrification (40% of miles traveled) the petroleum-reduction benchmark could be satisfied, even with high travel demand growth. The same highly electrified scenarios, however, could not satisfy 80% GHG-reduction targets, even assuming 80% decarbonized electricity and no growth in travel demand.
Their findings included:
None of the 9 reference scenarios met the 80% GHG reduction target, although 4 were below the 50% petroleum target and one was only slightly above.
In the petroleum-targeted scenarios, they substituted a hypothetical RFS-compliant advanced biofuel (i.e., advanced cellulosic biofuel) for gasoline on an energy basis, if needed, until the petroleum reduction target is exactly met—(i.e., to the point where gasoline and diesel consumption is reduced to 50% of 2011 levels).
Thus, petroleum requirements for all scenarios exactly meet, or are otherwise below, the 50% reduction target. None of the 40%-electrified cases required any contributions from cellulosic biofuel, as the electrification alone provided sufficient petroleum displace- ment.
No cellulosic biofuel was required under low growth and 20%-electrified conditions. The remaining five scenarios required widely varying contributions of cellulosic biofuel, from 316 to 8638 PJ. For comparison, they team estimated the RFS goal for cellulosic fuels to be equivalent to 1289 PJ.
The climate-targeted scenarios included cellulosic biofuel substitution to reduce GHG from light duty transportation to 20% of the reference GHG. The team also assumed that electricity is largely “decarbonized”, reducing GHG intensity by 80%.
No scenarios achieved the 80% GHG reduction without contributions from RFS-compliant advanced cellulosic biofuel. Only three scenarios actually met the GHG target of 294 MT. The remaining six scenarios exceeded the target even while replacing all petroleum with low GHG cellulosic biofuel (at 60% lower GHG intensity).
greencarcongress
Human history becomes more and more a race between education and catastrophe. H. G. Wells.
Fatih Birol's motto: leave oil before it leaves us.