Current Methods for Life-Cycle Analyses of Low-Carbon Transportation Fuels in the United States (2022) / Chapter Skim
Currently Skimming:
3 Life-Cycle Assessment in a Low-Carbon Fuel Standard Policy
3 Life-Cycle Assessment in a Low-Carbon Fuel Standard Policy
Pages 35-47
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 35... ...
Regulating only vehicle tailpipe emissions, for example, would unfairly advantage technologies that have upstream impacts but zero tailpipe emissions, such as battery electric or hydrogen fuel cell vehicles. Biofuels were, and continue to be, a focus in the development of LCA methods for LCFS because there are GHG emission sources along biofuel supply chains (e.g., N2O from farmland and fossil CO2 emissions from combustion of diesel fuel 35
|
From page 36... ...
. Despite the complexities of using LCA in a regulatory context, a desire to design policies that achieve GHG emissions reductions has motivated an increase in the use of LCA for policy development, particularly in the context of fuels LOW-CARBON FUEL POLICIES IN THE UNITED STATES, EUROPE, AND BRAZIL Although a comprehensive overview of international LCFS is outside the scope of this report, there are several examples of transportation fuel policies across the world that use LCA to varying degrees.
|
From page 37... ...
S Renewable Fuel Standard The RFS sets threshold GHG emissions reductions compared to a fixed baseline for petroleumderived fuels that a renewable fuel must achieve to be eligible for the program.
|
From page 38... ...
, as determined by the Administrator, related to the full fuel lifecycle, including all stages of fuel and feedstock production and distribution, from feedstock generation or extraction through the distribution and delivery and use of the finished fuel to the ultimate consumer, where the mass values for all greenhouse gases are adjusted to account for their relative global warming potential." FIGURE 3-1 Nested compliance categories in the EPA Renewable Fuel Standard (RFS2)
|
From page 39... ...
The California Low-Carbon Fuel Standard The CA-LCFS is a performance-based standard that requires obligated parties -- in this case, petroleum refiners and importers -- to reduce the CI of the fuel mix intended for road transportation supplied to the road sector, as assessed and approved by the California Air Resources Board (CARB)
|
From page 40... ...
. There are different GHG reduction requirements for fuels to qualify for RED II, depending on fuel type and what year a facility entered operation; fuels from facilities operating prior to October 2015 must generate at least 50 percent GHG savings as estimated by RED relative to the fossil fuel comparator; fuels from facilities entering operation in 2021 must generate at least 70 percent GHG savings.
|
From page 41... ...
None of these policies include emissions from changes in fuel markets that arise from changes in fuel production. CONSIDERATIONS IN APPLYING ATTRIBUTIONAL LIFE-CYCLE ASSESSMENT AND CONSEQUENTIAL LIFE-CYCLE ASSESSMENT IN LOW-CARBON FUEL STANDARDS Over the years, the use of LCA in the development of the RFS, CA-LCFS, and other policies across the United States and globally have been the subject of much discussion.
|
From page 42... ...
Although this wording does not explicitly require a particular approach, the phrase "related to the full fuel life cycle" has so far been interpreted as requesting a mostly ALCA: the task is to estimate emissions of processes "related to" fuel production and decide which of these emissions to allocate to fuel production and which to attribute to other co-products produced by the supply chain. There are a few caveats worth highlighting: CA-LCFS does assign offset/avoidance credits that are arguably more consistent with a CLCA approach.
|
From page 43... ...
The California Air Resources Board (CARB) supported the development of a CARB-specific version, called CA GREET, for use in California's Low Carbon Fuel Standard.
|
From page 44... ...
CONCLUSIONS AND RECOMMENDATION ON THE USE OF DIFFERENT LIFE-CYCLE ASSESSMENT APPROACHES IN LOW-CARBON FUEL STANDARDS This committee is in agreement that there is an important distinction between using LCA for policy implementation, policy design, and RIA. In all cases, a rigorous accounting of process-level emissions (e.g., fossil fuel combustion emissions at a refinery, N2O emissions on farms, and CH4 leakage at compressed natural gas production facilities)
|
From page 45... ...
Increased use of a fuel with a low carbon intensity, as defined in an LCFS, could potentially decrease or increase carbon emissions relative to the baseline, depending on policy design and other factors. Regulatory impact assessments that use CLCA to project the consequences of policy can help assess the extent to which a given policy design with particular carbon intensity estimates will result in reduced GHG emissions.
|
From page 46... ...
Research needs include: Further development of robust methods to evaluate the GHG emissions from development and adoption of low-carbon transportation fuels, and development or integration of process-based, economic input-output, hybrid, and CLCA methodologies Products could include the following: o development of national, open-source, transparent CLCA models for use in LCFS development and assessment o continued development of national, open-source ALCA models from new or existing models o evaluation of different approaches to creating, using, or combining ALCA, CLCA, and verification for evaluation of policy outcomes o quantification of variation between marginal and average GHG emissions for various feedstock-to-fuel pathways; and o quantification and characterization of the implications of approximations and proxies in LCA, such as comparisons of marginal and average emissions. Research goals include a comprehensive understanding of the implications of including or excluding various attributional and consequential emissions sources in LCFS CIs on the policy's resulting overall effect on net emissions and social welfare, as well as identification of opportunities to apply ALCA and/or CLCA to design policies that are well-aligned with their intended outcome.
|
From page 47... ...
2009. Greenhouse gas reductions under low carbon fuel standards?
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.