Emissions Changes from Electric Vehicle Use in Colorado Presented to the Regional Air Quality Council December 7, 2012 1
Background Electric Vehicles (EVs) have zero tailpipe emissions. Plug In Hybrid Electric Vehicles (PHEVs) have significantly lower tailpipe emissions than conventional vehicles However, upstream emissions associated with increased electricity generation and fuel cycle emissions (primarily coal and natural gas production) must also be considered. National and regional EV emissions calculators are a good start, but they don t paint the full picture for Colorado. Different generation profile than other states in our region Important to account for RPS, CACJA and Regional Haze benefits What is the actual effect on criteria pollutant and greenhouse gas emissions in the area? 2
Emissions Changes from Electric Vehicle Use in Colorado Jennie Jorgenson 1,2, Jennifer Detlor 3, Gregory Brinkman 2, and Jana Milford 1 1 Department of Mechanical Engineering, University of Colorado at Boulder 2 National Renewable Energy Laboratory 3 University of Wisconsin at Madison 3
AG/GHG Emissions Study Fortunate to have subject matter experts from NREL and CU Boulder on our team! Updating a previously published study to analyze the year 2020* 1. Dispatch Modeling (PLEXOS) simulates how power plants will react to increased electrical demand. Model every hour of every day of the year. 2. Life Cycle Emissions (GREET) accounts for emissions related to the extraction, production and transport of fuels used to generate electricity. 3. Motor Vehicle Emissions (MOVES) accounts for tailpipe emissions from conventional vehicles, as well as PHEVs Used in conjunction these 3 models will paint the full picture for potential emissions benefits from EV/PHEV deployment in Colorado. *. Brinkman, G.L., P. Denholm, M.P. Hannigan, and J.B. Milford. Effects of Plug in Hybrid Electric Vehicles on Ozone Concentrations in Colorado, Environmental Science and Technology, 44 (2010):6256 6262. 4
Modeling Two critical considerations of EV impact analysis: 1. Reflect real-world vehicle performance 2. Accurately characterize marginal source of electricity generation used to charge EVs Leads to two-part analysis: 5
Part 1: Dispatch Modeling Inputs: 1. Electricity demand in 2020 2. Constraints of system & units Model: Least cost method to serve electric load Output: Projected amount and source of electricity generation in 2020 All provisions of the Regional Haze SIP, CACJA and RPS were included as constraints. 6
Part 2: Life-Cycle Analysis Inputs: 1. Power plant emissions from Dispatch Model 2. Gasoline vehicle emissions from MOVES (S. Williams) 3. EV characteristics (FEVER consensus) 4. Other upstream emissions GREET Model - Greenhouse Gases, Regulated Emissions, and Energy use in Transportation Output: Life-cycle GHG Emissions associated with EVs in Colorado 7
Electric Vehicle Fleet How many EVs will we have in 2020? Most aggressive scenario: 480,000 7.5% of total light duty vehicle miles traveled Annual EV charging demand: 1500 GWh 1.9% of annual projected load 8
Electric Vehicle Fleet 14% When will they be charging? % of Daily Charging Per Hour 12% 10% 8% 6% 4% 2% Weekday Weekend 0% 12:00 AM 6:00 AM 12:00 PM 6:00 PM 12:00 AM 9
Aggressive Level Modeling Change in total generation by type resulting from aggressive EV adoption 2% (36GWh) 23% (475GWh) 31% (360GWh) 43% (662GWh) Coal Natural Gas Pumped Storage Wind Incremental Difference Generation Type GWh Coal 360 Natural Gas 662 Conv Hydro - Pumped Storage (36) Wind 475 Imports - Solar - Total Energy "In" 1,462 Exports - Pumped Load (52) Load 1,529 Total Energy "Out" 1,477 14000 Colorado Forecasted Dispatch with EVs in 2020 14000 12000 12000 Generation (MW) 10000 8000 6000 4000 Generation (MW) 10000 8000 6000 4000 Generation (MW) 2000 0 14000 12000 10000 8000 6000 4000 Tue Mar 10 Wed Mar 11 Thu Mar 12 Generation (MW) 2000 0 14000 12000 10000 8000 6000 4000 Fri Apr 17 Sat Apr 18 Sun Apr 19 Coal Hydro Pumped Wind Solar Gas 2000 0 Mon Jul 20 Tue Jul 21 Wed Jul 22 2000 0 Thu Nov 12 Fri Nov 13 Sat Nov 14 10
Full Fuel-Cycle Impacts: Energy Use Well-to-Wheels Energy Use Energy Use (Btu/Mile) 7,000 6,000 5,000 4,000 3,000 2,000 1,000 0 Vehicle Operation Fuel Feedstock Composite vehicle assumed VMTs were split as 28% PHEV 10, 28% PHEV 40 and 44% BEV 11
Full Fuel-Cycle Impacts: GHG Emissions Well-to-Wheels GHG Emissions 600 GHG emissions (g CO2-e/Mile) 500 400 300 200 100 0 Vehicle Operation Fuel Feedstock EV GHG emissions 45% reduction from CGV in base case. Reduction: 1628tpd NAA / 3205tpd statewide 12
Full Fuel-Cycle Impacts: NOx Emissions 0.30 Well to Wheels NOx Emissions NOx Emissions (g/mi) 0.25 0.20 0.15 0.10 0.05 0.00 Vehicle Operation Fuel Feedstock EV NOx emissions 30% reduction from CGV on annual basis for base case; 12% for summer (less wind) Reduction: 0.22tpd NAA/ 0.41tpd statewide 13
Full Fuel-Cycle Impacts: Criteria Pollutant and GHG Emissions 0.600 Well to Wheels Emissions Emissions (grams/mile) 0.500 0.400 0.300 0.200 0.100 Average Gasoline Composite EV - EV VOC emissions 70% reduction from CGV emissions for base case (annual or summer) VOC Reduction: 1.67tpd NAA/ 3.28tpd statewide EV SO 2 emissions higher than CGV SO 2 Increase: 0.06tpd NAA/.012tpd statewide 14
EV Emissions Comparison Percent Reduction in GHG Emissions Relative to CGVs 50% 45% 40% 35% 45% 33% 38% 30% 25% 20% 15% 10% 5% 0% FEVER DOE (AFDC) EPA DOE: Alternative Fuels and Advanced Technology Vehicles Data Center (http://www.afdc.energy.gov/afdc/vehicles/electric_emissions.php) EPA: Office of Transportation and Air Quality (http://www.fueleconomy.gov/feg/evtech.shtml) 15
Can EVs Reduce Net Emissions in Colorado? - Natural Gas and Wind are forecasted to account for over 65% of incremental electricity generation for EVs. - EV emissions of GHG, NOx, CO, VOC lower in all cases considered than emissions for conventional gasoline vehicles (CGV) - EV SO 2 emissions higher than CGV except with high baseline demand (natural gas supplies more incremental electricity demand) - Conventional EV Emissions Calculators underestimate the emissions reductions attainable via EV deployment. 16
Can EVs Reduce Net Emissions in Colorado? - As with any forecasting analysis, many assumptions underlie these results - Due diligence in form of sensitivity studies - In the meantime, FEVER will release the final report before the end of 2012 - Encourage widespread education on EVs 17
Questions? 18
Thank you! Sabrina M. Williams, Air Quality Specialist CDOT, Environmental Programs Branch Sabrina.williams@state.co.us 19