August 22, 2014 

# Low Carbon Fuel Standard 

# Reconsideration: CA - GREET Model Update California Environmental Protection Agency 

# Air Resources Board

## Workshop Purpose The LCFS reconsideration includes a proposed 

## CA - GREET version update

• This update will change pathway CIs

— many will rise

• In the interests of full transparency, we are presenting these changes to, and soliciting 

### feedback from, the public

• The information presented in these slides is preliminary, since work on CA - GREET 2.0 is 

### ongoing
August 22, 2014 2

## GREET Update Approach Direct GHG emissions have always been estimated using a model based on Argonne’s 

## GREET

• GREET is still preferred:

– Considered to be authoritative for U.S. fuel pathways

– Freely available to the public

– Very flexible; readily modified (spreadsheet format)



### • On the downside, GREET is:

– Very large and full of linked, sometimes recursive calculations

– Not easy to master August 22, 2014 3

## GREET Update Approach (Cont.) Argonne is aware of these drawbacks

• Has released a non - spreadsheet version: GREET.net

• Standalone application

• F ound it to be very promising

• Did not have time to make the transition during this 

### rulemaking

• Will consider adopting GREET.net in a future 

### rulemaking

August 22, 2014 4

## CA - GREET 1.8b & 2.0 Compared

• CA - GREET 2.0 is based on Argonne’s GREET 1 2013 (not CA - GREET 1.8b)

• CA - GREET 1.8b was based on Argonne’s GREET 1.8b



### • Updates from both ARB staff and Argonne are reflected in CA - GREET 2.0

• More pathways and feedstocks are built - in:

– Biomethane

– Used cooking oil to bio - and renewable diesel

– Corn oil biodiesel

— wet DGS - associated
August 22, 2014 5

## CA - GREET 1.8b & 2.0 Compared (Cont.)

• More pathways and feedstocks are built - in (Cont.)

– Animal waste biomethane pathway with methane emissions - avoided credit

– Liquefied - compressed natural gas (L - CNG)



### • Extensive life cycle inventory data updates

– Fertilizer production

– Farming and fuel production energy



### • Emission factors are updated

– Updated California on - road mobile - source emission factors from ARB’s EMFAC 2011 inventory

– Updated CNG/LNG tailpipe emissions data August 22, 2014 6

## CA - GREET 1.8b & 2.0 Compared (Cont.)

• Emission factors are updated (Cont.)

– Updated natural gas leakage rates

– Crude production emissions data from ARB’s OPGEE model

– Soil N 2 O emissions



### • Process efficiency factors are updated

• Electrical energy generation mixes are all based on 

### latest USEPA eGRID database

• Tier 1 pathway calculator for expedited estimation of first - generation pathway CIs



### • Some changes move CIs up; some move them down August 22, 2014 7

## Illustrative CI Examples

• Best way to summarize the differences is to look at actual direct (no ILUC) CIs



### • The following comparisons are tentative

– S till in the verification stage

– All values presented are still subject to change

– Final CA - GREET 2.0 version will go public when the 45 - day comment period begins



### • Tentative differences for baseline fuels

August 22, 2014 8

## Illustrative CI Examples (Cont.) Tentative differences for natural gas

• Fossil and landfill gas

• Shows effects of updated methane leakage rates (additional efforts to quantify are ongoing)

August 22, 2014 Model Version

Fuel 1.8b 2.0 Change N. American NG - CNG 68.01 78.37 10.36 N. American NG - LNG 83.13 96.92 13.79 Landfill Gas - CNG 11.26 33.52 22.26 Landfill Gas - LNG 26.31 54.50 28.19 9

## Illustrative CI Examples (Cont.) Tentative direct CI differences for biodiesel

August 22, 2014 Model Version Biodiesel Feedstock 1.8b 2.0 Change Soybean 21.25 23.90 2.64 Tallow 39.08 46.31 7.23 UCO 18.73 23.69 4.96 Canola 31.98 41.72 9.73 Corn Oil, WDGS - Associated 29.27 34.35 5.08

10

## Illustrative CI Examples (Cont.) Tentative direct CI differences for renewable 

## diesel

August 22, 2014 Model Version RD Feedstock 1.8b 2.0 Change Soybean 20.16 19.58 - 0.58 Tallow 39.33 44.56 5.23 UCO 17.22 19.26 2.04 Canola -- 36.85 -- Corn Oil, WDGS - Associated 29.72 -- --

11

## Illustrative CI Examples (Cont.) Tentative direct CI differences for sugarcane 

## ethanol

August 22, 2014 Model Version Sugarcane Ethanol Pathway 1.8b 2.0 Change No Harvest or Electricity Credit 27.40 34.55 7.15 Mechanized and Power Export 12.40 23.30 10.90 Mechanized Harvesting only -- 29.52 -- Power Export only 20.40 28.33 7.93

12

## Illustrative CI Examples (Cont.) Tentative direct CI differences for corn and sorghum ethanol

August 22, 2014 Model Version Pathway by Feedstock 1.8b 2.0 Change Grain Sorghum 61.83 71.47 9.64 Corn Ethanol (100 % NG) 68.32 59.86 - 8.46

13

## Current Work Priorities Staff is focusing on these priorities as we finalize the model

• CARBOB and USLD refining efficiencies



### • CNG and LNG truck tailpipe emission factors

• California NG leakage rate



### • Used Cooking Oil rendering energy

• Bio - renewable diesel production energy

August 22, 2014 14

## Summary The primary drivers of CI differences are:

• Corn , soybean, sorghum, and sugarcane CIs driven by changes in fertilizer use and soil N 2 

### O emissions

• Natural gas and biomethane pathways are higher 

### due to

– A n approximate doubling of the leakage rate, and

– An approximate 4x increase in pipeline energy requirements



### • Tallow and UCO pathways now account for the 

### transport of feedstocks

August 22, 2014 15

## Feedback and Contact Information We welcome your feedback

• Please submit feedback by September 15 th 

### , 2014

– Katrina Sideco, Staff Lead, LCFS Re - Adoption Team

• katrina.sideco@arb.ca.gov

• (916) 323 - 1082

– Hafizur Chowdhury, Staff Lead, Fuel Pathways Reconsideration Team

• hafizur.chowdhury@arb.ca.gov

• (916) 322 - 2275

August 22, 2014 16

## Contact Information (cont.)

– Wes Ingram, Manager , Fuels Evaluation Section

• wes.ingram@arb.ca.gov

• (916) 322 - 3984

– Chan Pham, CA - GREET Technical Team

• chan.pham@arb.ca.gov

• ( 916) 327 - 5600

– Todd Dooley, CA - GREET Technical Team

• todd.dooley@arb.ca.gov

• ( 916) 323 - 1069

August 22, 2014 17

## Thank You