Below are two methods to calculate the CO2 emissions, grams per km, of plug-in hybrid light-duty vehicles.?
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Method No. 1 is based on the energy input to the US power system in EV mode, and the energy of gasoline in gasoline mode.
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Method No. 2 is based on an EPA method which results in approximately 90 mpg equivalent values, based on combining the ?mileage? of EV and gasoline mode, as determined by standard tests that simulate different driving conditions.?
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Also provided is a description of the European approach which is based on Method No. 1.?
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As the US, Europe, China and Japan manufacture most of the world?s light-duty vehicles and export to each other, it is essential to have an easy-to-understand, global CO2 emissions standard in grams/mile that promotes the end result, which is less CO2 emissions from tailpipes and chinmeys.??
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METHOD No. 1: BASED ON US GRID CO2 INTENSITY
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In May 2012, the US finalized new standards to increase the corporate average fuel economy, CAFE, of cars and light trucks from the current 27.5 mpg to 35.5 mpg by 2016 and 54.5 mpg by 2025.
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The Chevy Volt was used to illustrate this method.
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Assumptions:
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The US power system CO2 emission intensity is 1.341 lb CO2/kWh.
Gasoline CO2 emission is 19.4 lb/gal
Chevy Volt (AC/DC conversion + charging) loss at 120 Volt is 16.1%, and at 240 Volt 8.9%?
Chevy Volt ?mileage? in EV mode is 0.30 kWh (DC)/mile (at the battery), or 0.3721 kWh (AC)/mile (produced by the power plant).
Chevy Volt mileage in gasoline mode is 37 mpg; EPA combined.
http://www.fueleconomy.gov/feg/noframes/31618.shtml
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Calculations:
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If 100% of the Chevy Volts were charging at 240 V, it would require 0.30 x 1.089 (AC to DC conversion + charging @ 240 V) x 1.05 (T&D) x 1.05 (Self-use) = 0.3602 kWh (AC)/mile to be produced by the US power system.?
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If 50% were charging at 120 V and 50% at 240 V, it would require 0.5 x 0.3602 + 0.5 x (1.161/1.089) x 0.3602 = 0.3721 kWh (AC)/mile to be produced by the US power system.?
http://theenergycollective.com/willem-post/171561/co2-emissions-and-chevy-volt-vs-honda-civic-ex-l?
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Chevy Volt CO2 emissions in EV mode = 0.3721 kWh/mile x 1.341 lb CO2/kWh x 454 gr/lb x 0.6214 m/km? = 140.8 gr/km.?
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Chevy Volt CO2 emissions in gas mode = 19.4 lb CO2/gal x 454 gr/lb x 1 gal/37 mile x 0.6214 m/km = 147.9 gr/km? ?
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Below is a comparison of 4 cases of travel.
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? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? Travel? ? ? ? ? ? ? ? ? Mileage? ? ? ? Energy ? ? ? ? ? ? ? ? ? Emissions ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
?? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? miles/yr? ? ? ? ? ? ? ? ? mpg? ? ? ? ? ? ? ? ? ? ? ? ? ? ? lb CO2/yr? ? ? g CO2/km ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
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Present CAFE ? ? ? ? ? ? ? ? ?12,000 ? ? ? ? ? ? ? ? ?27.5 ? ? ? ? ?436 gal ? ? ? ? ? 8,465? ? ? ? ? 199.0 ? ? ? ? ?
2025 CAFE ? ? ? ? ? ? ? ? ? ? 12,000 ? ? ? ? ? ? ? ? ?54.5 ? ? ? ? ?220 gal ? ? ? ? ? 4,272? ? ? ? ? 100.5
Chevy Volt, EV mode ? ? ? 12,000? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? 4,465 kWh ? ? ? ? 5,748? ? ? ? ? 140.8
Chevy Volt, Gas mode ? ? ?12,000? ? ? ? ? ? ? ? ? 37.0? ? ? ? ? 324 gal ? ? ? ? ? 6,292? ? ? ? ? 147.9
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The above table indicates, the Chevy Volt is slightly more efficient in EV mode than in gas mode regarding grams of CO2 emissions/km. The CO2 either comes out of a Chevy Volt tail pipe, or out of a power plant chimney.?
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METHOD No. 2: BASED ON EPA's APPROACH
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The ?mpg equivalent? metric, introduced in November 2010 by the EPA, is based on 33.7 kWh per gallon of gasoline. The energy consumption of a vehicle is determined by the EPA's five standard drive cycle tests simulating varying driving conditions. All new cars and light-duty trucks sold in the U.S. are required to have a label showing the EPA's estimate of fuel economy of the vehicle.?
http://en.wikipedia.org/wiki/Miles_per_gallon_gasoline_equivalent
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Chevy Volt in EV mode uses 35 kWh/100 miles, per EPA.
Chevy Volt EPA mpg-e = 100 m/35 kWh x 33.7 kWh/gal = 96.3 mpg-e. (the below website states 98 mpg-e.)?
Chevy Volt in gas mode uses 37 mpg, per EPA
http://en.wikipedia.org/wiki/Plug-in_hybrid
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The EPA method has no basis in physical reality regarding CO2 emissions/mile and is highly deceptive, because it causes people to think the building of millions of plug-in hybrids would be a significant factor to reduce CO2 emissions, whereas in fact, plug-in hybrids would hardly make a difference, as shown under Method No.1.
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But, the overstated EPA values do serve a political purpose, as it allows car makers to use these values for calculating their CAFE values, which would make it much easier to comply with the 2025 CAFE standard; a loophole designed large enough for an 18-wheeler.
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Note: Earlier CAFE standards were rife with loopholes which resulted in a difference between the EPA test mpg and real-world mpg of up to 20%. Washington?s ?constituent service providers? should be less lenient in the future.
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http://theenergycollective.com/jemillerep/104841/can-new-cafe-standards-deliver-promised-benefits?
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DESCRIPTION OF EUROPE's APPROACH
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A more rational approach is for the EPA to follow the European method based on grams/kilometer.?It is more realistic, less deceptive, and less confusing to the public.
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For a European car sold in the US, the EV mode would be based on the US grid CO2 emissions intensity of 1.341 lb CO2/kWh, which would be slowly decreasing as more CO2-free energy is added to the grid.
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The gasoline mode would be based on the energy in a gallon of gasoline.?
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Each light duty vehicle would have its CO2 emissions stated in grams/mile and grams/km.
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In Europe, road transport contributes about one-fifth of the EU's total emissions of CO2. Emissions of CO2 from road transport increased by nearly 23% between 1990 and 2010; without the economic downturn, the increase would have been greater. Transport is the only major sector in the EU where CO2 emissions are still increasing.
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http://ec.europa.eu/clima/policies/transport/vehicles/index_en.htm
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LIGHT-DUTY VEHICLE CO2 EMISSION STANDARDS
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Light-duty vehicles are a major source of greenhouse gas emissions, producing around 15% of the EU's emissions of CO2.
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Following up on a European Commission strategy adopted in 2007, the EU has put in place a comprehensive legal framework to reduce CO2 emissions from new light duty vehicles as part of efforts to ensure it meets its greenhouse gas emission reduction targets under the Kyoto Protocol and beyond.
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The legislation sets binding emission targets for new light-duty vehicles. As the automotive industry works towards meeting these targets, average emissions, gram/km, have decreased each year.
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In July 2012, the Commission proposed legislation setting out the modalities for implementing the 2020 targets.
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The Commission plans to issue a communication at the end of 2012 seeking stakeholders' views on post-2020 emission targets for new light-duty vehicles. The intention is to ensure that CO2 emissions from light-duty vehicles continue to be reduced while giving the automotive industry the certainty it needs to carry out long-term investments and develop innovative technologies. Any proposal of future targets will be based on a thorough assessment of their economic, social and environmental impacts.
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Cars
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For cars, manufacturers are obliged to ensure that their new car fleet does not emit more than an average of 130 grams of CO2 per kilometer (g CO2/km) by 2015, and 95 g by 2020. This compares with an average of about 160 g in 2007 and 135.7 g in 2011.
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The 2015 target equates to 5.6 liters per 100 km (l/100 km) of gas, or 4.9 l/100 km of diesel.?
The 2020 target equates to 4.1 l/100 km of petrol, or 3.6 l/100 km of diesel.
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Vans
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For vans the target is 175 g CO2/km by 2017 and 147 g by 2020. This compares with an average of about 203 g in 2007 and 181.4 g in 2010.
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The 2017 target equates to 7.5 l/100 km of gas, or 6.6 l/100 km of diesel.?
The 2020 target equates to 6.3 l/100 km of gas, or 5.5 l/100 km of diesel.
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Penalty Payments for Non-Compliance; applies to cars and vans
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If the average CO2 emissions of a manufacturer?s fleet exceeds its limit value in any year from 2012, the manufacturer has to pay an excess emissions premium for each car registered. This premium amounts to 5 euro for the first g/km of exceedance, 15 euro for the second g/km, 25 euro for the third g/km, and 95 euro for each subsequent g/km. From 2019, the cost will be 95 euro from the first gram of exceedance onwards.
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CO2 Emission Labelling of Cars and Vans
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To help drivers choose new cars with low fuel consumption, EU legislation requires Member States to ensure that relevant information is provided to consumers, including a label showing a vehicle's fuel efficiency and CO2 emissions.
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Heavy-duty Vehicles
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Heavy-duty vehicles (HDV) - trucks and buses - are responsible for about 25% of CO2 emissions from road transport in the EU, and for some 6% of total EU emissions. Despite some improvements in fuel consumption efficiency in recent years, HDV emissions are still rising, mainly due to increasing road freight traffic.
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The Commission is currently working on a comprehensive strategy to reduce CO2 emissions from HDVs in both freight and passenger transport.
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Fuel Quality
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Fuel quality is an important element in reducing greenhouse gas emissions from transport. EU legislation requires the greenhouse gas intensity of vehicle fuels to be cut by up to 10% by 2020.
Source: http://theenergycollective.com/willem-post/184756/plug-hybrid-mileage-overstated-epa
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