CA-GREET 2.0 Model
This page last reviewed May 6, 2016
At its September 2015 hearing, the California Air Resources Board (Board) approved the re-adoption of the California Low Carbon Fuel Standard (LCFS). Among the approved items is the updated version of the California-modified Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (CA-GREET) model. LCFS fuel pathways are grouped into either Tier 1 or Tier 2 under the adopted LCFS regulation. The fuels that fall into these two tiers are described below. Slightly different versions of the model are used to calculate Tier 1 and Tier 2 CIs. The Tier 1 version is called CA-GREET2.0-T1, while the Tier 2 version is called CA-GREET2.0-T2. Because these versions contain the same data tables (they differ only in how CIs are calculated), they are collectively referred to as “CA-GREET 2.0.” Both models, along with documentation of the sources of the data they contain, are posted to this page.
In 2009, the Board approved the original LCFS regulation order. That order designated CA-GREET, version 1.8b as the model to be used for estimating direct life cycle emissions from the production, transport, and use of transportation fuels. CA-GREET 1.8b has remained in use since this original Board approval.
The regulation order the Board adopted at its September 2015 hearing replaces CA-GREET 1.8b with CA-GREET 2.0. Both CA-GREET versions are based on versions of the national GREET model developed at Argonne National Laboratory. The version currently in use was developed from Argonne’s GREET 1.8b, and the proposed new version was developed from GREET1 2013. Argonne’s currently supported GREET versions are available on its website.
The changes staff made in converting GREET1 2013 into CA-GREET 2.0 are documented in the Supplemental Document . First- and next-generation fuels are referred to as “Tier 1” and “Tier 2” fuels, respectively, in the current regulation. The difference between first-generation and innovative/next-generation fuels is easily ascertained from the model: fuels not included in the Tier 1 model are in the Tier 2 category.
September 29, 2015 Release
- CA-GREET 2.0 Tier 1 for 23 common conventionally produced first-generation fuels (starch- and sugar-based ethanol, biodiesel, renewable diesel, CNG, LNG).
- CA-GREET 2.0 Tier 2 for next-generation fuels (cellulosic alcohols, hydrogen, drop-in fuels, etc.) or first-generation fuels produced using innovative production processes.
- CA-GREET 2.0 Supplemental Document
The carbon intensities (CIs) of the LCFS baseline fuels—California reformulated blendstock for oxygenate blending (CARBOB), California reformulated gasoline (CaRFG), and California ultra-low sulfur diesel (ULSD)—are also determined using CA-GREET 2.0 (in conjunction with the Oil Production Greenhouse Gas Emissions Estimator, or OPGEE. The CIs of CARBOB and ULSD are have already been using CA-GREET 2.0 (which contains the necessary crude recovery and transport emissions data from the OPGEE model). Calculating the CI of CaRFG, however, is more complicated. The CIs of the ethanol blendstock (itself a blend of ethanol with various CIs), the CARBOB, and the denaturant in the ethanol must all be properly accounted for. The spreadsheet staff uses to calculate the CI of CaRFG is called the California Reformulated Gasoline and Ethanol Denaturant Calculator
- December 2009 California-GREET Model version 1.8b (modified by Life Cycle Associates LLC)
- February 2009 California-GREET Model version 1.8b (modified by Life Cycle Associates LLC)
- December 2008: California-GREET Model version 1.8b (modified by Life Cycle Associates LLC)
- September 2008: California-GREET Model version 1.8b (modified by Life Cycle Associates LLC)
- February 14, 2008: California-GREET Model 1.7 version 98
- Original GREET Model version 1.8b from ARGONNE National Laboratory
Contact UsIf you have general questions regarding the information posted to this site, please contact Mr. Anil Prabhu, Manager, Fuel Evaluations Section; for more technical, CA-GREET-specific questions, please contact Mr. Chan Pham, Air Resources Engineer.
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