Plug-In Folly Part 4 by Pat Murphy, Plan Curtail PART 4A: The Plug-In Hybrid Car – Inventing the Plug-in Hybrid P1 The first plug-in hybrid car in the US was shipped in December 2010. Because this new type of car used both gas and electricity, both needed to be included in MPG and CO 2 Emissions calculations. As with battery electric cars, claims about the fuel economy of plug in hybrids were wildly inflated which led to it becoming the darling of American politicians and advocacy groups. P2 An entirely new way to compute miles per gallon, called by the confusing name, Charging Routines, came out of the Prius conversion industry. A review of the computation methodology later exposed important misrepresentations, but Congress had already bought into the plug in hybrid. P3 A plug-in hybrid is a battery electric car with a gasoline engine that recharges the battery as the car is being driven. Such cars overcome the limited range of a battery car by using a gasoline engine as a “range extender”. The Chevrolet Volt was the first P4 production plug-in hybrid. The first shipments occurred in December 2010. November 2015 Plug-In Hybrids Page 1 of 19
Plug-In Folly Part 4 by Pat Murphy, Plan Curtail P5 The automotive world had been surprised in August 2009 when new General Motors President Fritz Henderson announced a fuel economy rating of 230 miles per gallon for the forthcoming Volt. Suddenly, the concept of a plug-in hybrid was transformed from an extended range, mostly electric car, to a vehicle that claimed to have much higher miles per gallon than a battery electric vehicle or a hybrid P6 Many scientists and members of the automotive press challenged the EPA to verify this number, arguing that such a number was simply not realistic. The EPA acknowledged that it “ had not tested a Chevy Volt and therefore could not confirm the fuel economy values claimed by GM.” P7 But in the same statement the EPA praised “GM’s commitment to designing and building the car of the future – an American-made car that will save families money, significantly reduce our dependence on foreign oil and create good paying American jobs.” The EPA has long been supportive of electric cars and its praise for the Volt is not unexpected, although not necessarily accurate. P8 GM’s 230 miles-per-gallon number was obtained by first using the Department of Energy well to wheels method of determining miles-per- gallon equivalency. The Volt window sticker shows 36 kwh is used to drive 100 miles. To calculate the Volt MPG, the 100 miles is divided by 36 kwh giving 2.3 miles per kilowatt hour. This number is multiplied by 12.3 kilowatt hours per gallon giving 35 miles-per- gallon equivalent. November 2015 Plug-In Hybrids Page 2 of 19
Plug-In Folly Part 4 by Pat Murphy, Plan Curtail P9 Next GM applied a calculation from the Department of Energy’s Corporate Average Fuel Economy (CAFÉ) Standard that divides the 35 miles per gallon by an arbitrary value of 0.15. This gives the approximate 230 miles- per- gallon number quoted by GM’s president. This arbitrary value of 0.15 was P10 defined in the 2000 Final Rule recorded in the U.S. Federal Register that established the DOE’s miles-per- gallon calculation method. Its purpose was to provide an incentive to automakers to include electric cars in their offerings — it was not intended to accurately represent their fuel economy. P11 The EPA published a Volt window sticker in November 2010 – 14 mo nths after GM’s 230 MPG announcement, with a fuel economy of 60 miles-per-gallon equivalent. With the publication of this window sticker, GM agreed to stop using 230 MPG for the Volt’s miles -per-gallon value. It took a surprisingly long time – over a year - to resolve the original 230 miles-per- P12 gallon claimed by GM. But while refuting the GM claim with the November 2010 window sticker, at the same time the EPA added another questionable way of determining miles-per-gallon equivalency which it called Charging Routines. November 2015 Plug-In Hybrids Page 3 of 19
Plug-In Folly Part 4 by Pat Murphy, Plan Curtail Part 4B: The Plug-In Hybrid – MPGe – Prius Conversions P13 The new way of calculation Miles per gallon, was derived from an effort to convert conventional Priuses to so called Plug In Priuses. P14 MPG calculations for plug-in hybrid vehicles differs from both the original EPA and Department of Energy methods. The calculation method appears to have come from a movement that began in 2004 with the conversion of a standard Toyota Prius to a plug-in. P15 Felix Kramer formed CalCar Initiatives in 2002 to advocate for plug-in hybrid cars. In 2004 Kramer and Ron Gremban made a plug-in hybrid by adding lead acid batteries and a charger to a 2004 Prius. Their efforts were partially based on the work of Dr. Andrew Frank. P16 Andy Frank, at that time a member of the faculty of the University of California at Davis, is often referred to as the “Father of the Pluggable Hybrid.” He has converted more than a dozen different vehicles to plug-in hybrids over a 20-year period . November 2015 Plug-In Hybrids Page 4 of 19
Plug-In Folly Part 4 by Pat Murphy, Plan Curtail P17 One of these conversions was made to a General Motors EV1. A gasoline engine with an electric generator was added to the basic EV1 to charge the car’s batteries. This may have served as a concept model for the Volt. P18 The idea of a plug-in hybrid car had been long supported by the electric power industry, particularly by the Electric Power Research Institute, known as EPRI. In 1991 EPRI formed a collaborative P19 with General Motors, Ford, Chrysler and the Department of Energy to found the U.S. Advanced Battery Consortium in order to respond to the California Air Resources Board mandate for electric cars. P20 An important concept document was published by EPRI in July 2001 with the title of “Comparing the Benefits and Impacts of Hybrid Electric Vehicle Options.” The report stated that the goal of the power industry was to pursue electric cars, including plug-in hybrids. EPRI provided financial support to some plug-in hybrid advocates. November 2015 Plug-In Hybrids Page 5 of 19
Plug-In Folly Part 4 by Pat Murphy, Plan Curtail P21 In 2005 Calcars converted a newer version of Prius to a plugin using lithium-ion batteries. CalCars adopted the logo “100 + miles per gallon” for this car. CalCars miles-per-gallon claim was P22 more than twice that of an unmodified Prius of the same model year, which had a fuel economy rating of 46 miles per gallon. P23 The early fuel economy claims for converted Priuses gave the impression of dramatic miles per gallon breakthrough. However, the claims were more of a marketing breakthrough than an engineering one. November 2015 Plug-In Hybrids Page 6 of 19
Plug-In Folly Part 4 by Pat Murphy, Plan Curtail Part 4C: The Plug In Hybrid Car – Understanding Charging Routines P24 Why were the MPG equivalent numbers for plug-ins so high? How were these numbers determined? It’s a complex and intriguing story. The EPA was involved briefly when it use the term Charging Routines to describe the method. P25 Robert Lutz, the General Motors executive behind the Volt wrote in his 2010 book Chevrolet Volt: Charging into the Future “ This is not about maximizing range or computationally getting the maximum efficiency. This is about permitting the average American to drive fully electrically most of the time but with the backup of a gasoline engine.” The computation method that P26 provided such high fuel economy claims was first illustrated by Lutz, using the example of a person who charged his or her Volt once daily. Lutz said this person would get 150 miles per gallon. GMs method of calculating MPGe P27 used three terms: DIST = Distance traveled between charges MPGg = Miles per Gallon of the gasoline engine MPG d = Miles Drivable between Charge - the number of miles that could be driven with a fully charged battery. November 2015 Plug-In Hybrids Page 7 of 19
Plug-In Folly Part 4 by Pat Murphy, Plan Curtail P28 The formula for this MPGe method is the product of the Distance Traveled between charges and the miles per gallon for the gasoline engine …. P29 … divided by the difference of the Distance Traveled between charges and the electric vehicle range possible on a full charge. P30 Lutz obtained his 150 miles-per-gallon equivalent rating using 60 miles for Distance Driven, 50 miles per gallon for the gasoline engine, and an electric vehicle range of 40 miles. Solving this simple equation gives 150 miles-per-gallon equivalent . P31 It appears that the EPA used this formula in its November 2010 window sticker for the Volt in the section entitled “Examples: Charging Routines” as was previously noted. November 2015 Plug-In Hybrids Page 8 of 19
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