em • feature CASE STUDY by Meganne Arens GM’s Advanced Propulsion Meganne J. Arens, APR, for GM Environment & Energy Communications, Technology Strategy Corp., Detroit, MI. The automotive industry is in a very turbulent period. However, what is certain is that today more than one-third of the world’s energy needs are met with petroleum and that the automobile is 96% dependent on fossil fuels. Supply and availability, fuel prices, sustainable growth, climate change, and even national security all have a common denominator: oil.

24 em may 2009 Copyright 2009 Air & Waste Management Association awma.org As a business necessity and as our obligation to society, GM is working to bring all of these technologies to General Motors Corp. (GM) believes the global auto- market using its global organization with common methods motive industry must develop alternative sources of and systems within the company’s global product devel- propulsion, based on diverse sources of energy, to meet opment, manufacturing, and purchasing departments. The the world’s rapidly growing demand for personal trans- goal is to provide transportation solutions that meet the portation that is sustainable and affordable to purchase varied needs of markets around the world. Solutions for a and operate. Energy and environmental leadership are given area will be based on a variety of factors, including keys to GM’s future business strategy. local fuel resources and consumer driving patterns.

At GM, we believe that: As a full-line automaker, GM is pursuing energy • Electrically-driven vehicles are the best solution to diversity across its product lineup by developing vehicles GM believes address society’s energy and environmental concerns. that can be powered by advanced propulsion systems that innovation, • There is no singular solution to the issue of propulsion using many different energy sources that displace and energy technology. Several sources of energy will petroleum. In addition to its intensive efforts to improve efficiency improve- be needed to reduce global reliance on petroleum the efficiency of internal combustion engines and to dis- ments, and energy and the automobile’s impact on the environment, place traditional petroleum-based fuels with biofuels like diversity are keys while successfully meeting the growing global demand E85 ethanol (a mixture of up to 85% denatured fuel for personal transportation. ethanol and gasoline), GM is also significantly expanding to sustainable and accelerating the development of electrically driven global economic Petroleum has been one of the world’s primary energy vehicles, including hybrids, plug-in hybrids, extended- development. sources for more than a century because of its relative range electric vehicles, and hydrogen fuel-cell vehicles. abundance, high energy density, and ease of transportation. As the demand for automobiles around the world has In the long term, GM considers a variety of energy grown (and continues to grow), so too has the demand sources to have viable places within the transportation for fuel to power these automobiles. Recognizing these sector, including gasoline, diesel, ethanol, natural gas, trends around global energy issues, GM believes that and biodiesel, each contributing toward a globally diverse innovation, efficiency improvements, and energy diversity energy strategy. are keys to sustainable global economic development. Advanced Gasoline Engines To meet these challenges in the automotive sector, GM and Transmissions has developed a strategy that is focused on utilizing a Traditional engines and transmissions will continue to variety of advanced propulsion technologies and fuels to play a significant role in transportation around the globe deliver transportation solutions to markets around the as newer technologies move through development, world (see Figure 1). Challenges to development and growth, and maturation phases. With this in mind, GM implementation do exist. However, they are not insur- continues to make improvements to the traditional gasoline mountable and GM is working closely with key stake- engine with features such as Active Fuel Management, a holders to address these issues each step of the way. technology that saves fuel by using only half of the engine’s cylinders when driving with a light load and GM’s advanced propulsion technology strategy focuses then seamlessly switching to all cylinders when needed on three main areas: for brisk acceleration or for hauling heavy loads.

1. Advanced gasoline engines and transmissions: Con- Other advanced technologies like Variable Valve Timing tinuously improve engines and transmissions that and Direct Injection also help to improve fuel economy achieve greater efficiency and reduced emissions. and emissions performance in traditional vehicle systems. 2. Alternative fuels: Accelerate the use of alternative Additionally, the aggressive rollout of six-speed auto- fuels through biofuel-capable propulsion systems. matic transmission technology in GM vehicles has 3. Electrification: Drive the electrification of the vehicle helped to support the goal of improved fuel economy by developing and marketing hybrids, plug-in hybrids, and reduced emissions. In fact, by the end of 2009, extended-range electric vehicles, and hydrogen GM will have introduced 10 new variants of six-speed fuel-cell vehicles. transmissions. awma.org Copyright 2009 Air & Waste Management Association may 2009 em 25 Figure 1. GM’s advanced propulsion technology.

Alternative Fuels and trucks. GM is on track to make 50% of its annual Ethanol vehicle production volume in North America E85-capable In the near term, GM believes ethanol has the greatest by 2012. In Europe, the Saab 9-5 BioPower is the best- potential to displace petroleum, and the company is selling flex-fuel vehicle, and Saab recently added the committed to working with government, academia, and 9-3 line with BioPower variants. In Brazil, more than 95% industry to promote both supply and availability. of GM’s vehicles are flex-fuel-enabled, allowing the Ethanol’s benefits include that it comes from renewable vehicles to run on 100% ethanol or a blend of 22% sources and that it produces fewer greenhouse gas ethanol and gasoline. Brazil’s ethanol primarily comes (GHG) emissions than gasoline.1 Based on results of a from domestically grown sugar cane. Brazil is a net recently concluded nine-month study by Sandia National exporter of ethanol and the second-largest producer Laboratory and GM, 90 billion gallons of ethanol could following the United States. be produced annually in the United States by 2030, offsetting up to one- third of U.S. petroleum use for Ethanol as a transportation fuel has its detractors. Much approximately the same cost as expanding on-shore oil has been written about the impact on U.S. food prices drilling and refining.2 and food availability globally because of ethanol, but after several months in 2008 when ethanol was blamed Most ethanol today is blended into gasoline as a gasoline for record prices for corn, the bushel price of corn has additive at 10% volume, called E10. GM’s preference is dropped by 40% from its highs, while ethanol has E85 ethanol, which is an alternative fuel as opposed to a followed petroleum, dropping to less than half its peak gasoline additive. Comparatively minimal investment is price. Meanwhile, food prices have continued to rise.3 required by manufacturers to reengineer traditional internal combustion engines to flex-fuel engines, making A second criticism of ethanol, and the subject of an them capable of running on E85, ordinary gasoline, or ongoing environmental debate, is whether and how any combination of the two. much impact ethanol production directly and indirectly affects land use as corn production is used for ethanol More than 7 million flex-fuel vehicles are on the road in instead of food and feed. The argument goes that new the United States today, and more than half are GM cars land in other parts of the world is converted to food

26 em may 2009 Copyright 2009 Air & Waste Management Association awma.org production, releasing stored carbon because land in the for 16 billion gallons of the RFS. Advanced biofuels are United States that was used to grow corn for food is now expected to account for the remaining 5 billion gallons. used to grow corn for ethanol. GM has alliances with two cellulosic ethanol firms, Studies released in early 2008 that suggested ethanol Coskata Inc. and Mascoma Corp., that are viewed as production in the United States was leading to the burn- leaders in biothermal and biochemical ethanol conversion ing of rain forests in Brazil received significant attention.4 processes, respectively. A recent series of articles But in the months since their release, the conclusions of published in Biofuels, Bioproducts, and Biorefinining the studies have been criticized by numerous scientists concludes that most cellulosic biofuel scenarios offer and scientific organizations as lacking substantiation.5 comparable, if not lower, costs and much reduced GHG The U.S. Environmental Protection Agency is currently emissions (>90%) compared to petroleum-derived considering how to count direct and indirect land use fuels.6 According to a 2007 study by Argonne National change in GHG calculations of corn and cellulosic Laboratory, corn ethanol averages a 19% reduction in ethanol required as part of the Energy Independence GHG emissions compared with gasoline.7 and Security Act of 2007 that raised the Renewable Fuels Standard (RFS) to 36 billion gallons per year by Electrification 2022. The third piece of GM’s technology strategy focuses on the electrification of the vehicle.8 GM is a strong propo- Corn, which is capped at 15 billion gallons of the RFS, is nent of this technology, as it offers excellent perform- increasingly being seen as a transitional feedstock to ance and enables zero vehicle emissions. Using electricity nonfood biomass sources. Urban, agricultural, and as the primary energy carrier can improve vehicle en- forestry waste, such as corn stalks, lumber mill waste, ergy consumption and lower customer costs as the elec- and energy crops, are expected to be among the lead- tric energy is generated by utility companies at a ing feedstocks of second-generation ethanol and account high-efficiency power plant. awma.org Copyright 2009 Air & Waste Management Association may 2009 em 27 Hybrids Cadillac Escalade full-size sport-utility vehicles, as well as GM’s advanced propulsion technology strategy incorpo- two- and four-wheel drive versions of the rates a variety of technologies that will provide increased Silverado and GMC Sierra Crew Cab full-size trucks. The use of electricity as the propulsion source for vehicles of 2-Mode system incorporates two 60-kW electric motors all sizes and types. GM’s experience with electrification and is combined with a V-8 gasoline engine that utilizes is rooted in the landmark EV1 pure electric car, and GM’s Active Fuel Management technology to deactivate more recently, in a variety of contemporary hybrid vehicles cylinders and cam-phasing strategies that de-throttle the that combine internal combustion propulsion with engine even further by the late closing of the intake electric drive modes. Today, GM offers several hybrid valves. With full-size utilities such as the versions of its cars and sport-utility vehicles. and GMC Yukon, the 2-Mode system increases mileage by 50% in city driving and delivers an overall fuel The GM hybrid system featured on the savings of 30%. The system provides electric drive up Hybrid, for example, saves fuel by using sophisticated to 30 mph, even when the truck is loaded with cargo or controls and software, as well as a unique, 36-volt electric towing a trailer. motor/generator mated to GM Powertrain’s 2.4L Ecotec VVT four-cylinder engine. The GM hybrid system main- Extended-Range Electric Vehicles tains the vehicle’s sporty feel and seamlessly reduces fuel In addition to hybrid vehicles, GM is also readying consumption by: its first production car based on its innovative Voltec system, which is designed for electric propulsion and • shutting off the engine when the vehicle is stopped, is adaptable to a variety of onboard power generating to minimize idling; systems, such as internal combustion engines and • restarting the engine promptly when the brake pedal fuel-cell engines. is released; • enabling extended fuel shut-off during vehicle The first application of this system is the , deceleration; which GM plans to introduce in late 2010. The Volt is an • capturing vehicle kinetic energy during deceleration extended-range electric vehicle (EREV) that uses lithium through regenerative braking to charge the advanced ion batteries to store electric power in the vehicle. The nickel metal hydride battery; and Volt delivers up to 40 miles of gasoline- and emissions- • performing intelligent battery charging when it is free driving. Volt’s on-board range-extending engine is most efficient. used to create electricity after the battery’s energy has been depleted. The range-extending engine, which will When required, the GM hybrid system provides additional be capable of using either gasoline or E85 ethanol fuel, launching power from the electric motor/generator. At is able to generate additional electricity to power the car wide-open throttle, such as during a passing maneuver, for hundreds of additional miles. The Volt can be the system enhances acceleration by using the motor/ recharged in less than three hours using a standard generator to bolster the internal combustion engine. 240-volt electrical outlet or approximately eight hours using a standard 120-volt electrical outlet. GM’s 2-Mode hybrid system was pioneered for transit buses in 2003. The 2-Mode hybrid system is a techno- Hydrogen Fuel-Cell Vehicles logical breakthrough in electrification as it is scalable to In addition to hybrids and EREVs, hydrogen fuel-cell vehicles of all sizes—something not practical with vehicles also offer an electric transportation option that competitive systems. It enables two electrically variable GM is pursuing. Since 2001, GM has developed a transmission modes that allow for high efficiency in both range of fuel-cell prototype vehicles to demonstrate its low- and high-speed operation. In addition to avoiding commitment to advancing the technology and exploring fuel consumption during vehicle standstill by shutting off the viability of petroleum-free transportation. Previous the engine, the system enables regenerative braking, and concepts included the HydroGen3, which demonstrated the ability to increase the time the engine operates at its how a could be packaged in a conventional most efficient speed and load. vehicle design; the Autonomy, which suggested an entirely new design ethic combined with fuel-cell and In the United States, GM has rolled out the 2-Mode by-wire technology; and the Hy-wire, the world’s first hybrid system to the Chevrolet Tahoe, GMC Yukon, and drivable fuel-cell and by-wire vehicle.

28 em may 2009 Copyright 2009 Air & Waste Management Association awma.org In 2006, the Chevrolet Sequel concept fuel-cell vehicle was demonstrated to the media, proving that fuel-cell vehicles could drive 300 miles (480 km) between hydrogen fill-ups, with its only exhaust emissions being water vapor. The success of the Sequel demonstration then helped GM to launch Project Driveway in early 2008. Project Driveway is a fuel-cell vehicle market test that is placing 100 Fuel Cell vehicles in the hands of customers around the United States and Europe. Drivers are using the vehicles as daily trans- portation for up to three months and providing valuable feedback to GM engineers on the driving characteristics, driving range, and other real-world evaluations of the vehicles.

Onboard vehicle fuel storage is a major challenge for implementing mainstream fuel-cell vehicles, as customers will demand driving ranges comparable to conventional internal combustion-powered vehicles. Compressing the hydrogen gas for vehicle storage is still in the early stages of technological development. Three major advanced storage concepts remain under development, including complex (destabilized) hydrides, high-pressure classic hydrides, and high-surface area/cryo-adsorbents.

GM is committed to producing a viable fuel-cell propulsion system that is competitive with passenger cars concerning performance, range, and passenger and cargo space. How quickly there will be significant volumes of exciting, Conclusions safe, and affordable fuel-cell vehicles on the market GM recognizes that the automotive industry must bring depends on many factors, including cost-effective and new technologies to market that capitalize on the benefits conveniently available hydrogen refueling for customers; of energy diversity and reduce the impact automobiles uniform codes and standards for hydrogen and hydrogen- have on the environment. Local conditions also require fueled vehicles; and supportive government policies to local solutions as no one technology or fuel meets the help overcome the initial vehicle and refueling infra- needs of drivers around the globe. For its part, GM is structure investment hurdles. No single industry can go committed to meeting and overcoming these challenges it alone: GM is working these issues with governments, through continued partnership and innovation, and energy companies, and other interested parties around providing sustainable mobility to please our customers the world. around the world. em

References 1. Laser, M. et al. Comparative Analysis of Efficiency, Environmental Impact, and Process Economics for Mature Biomass Refining Scenarios; Biofuels, Bioprod. Bioref. 2009, 3, 247–270; doi: 10.1002/bbb.136. 2. 90 Billion Gallons Biofuels Deployment Study; Sandia National Laboratory. Prepared for General Motors Corp., February 2009; www.HITECtransportation.org. 3. See http://tinyurl.com/Vilsack-Ethanol-Food-Prices. 4. Searchinger, T.; Heimlich, R.; Houghton, R.A.; Dong, F.; Elobeid, A.; Fabiosa, J.; Tokgoz, S.; Hayes, D.; Yu, T.-H. Use of U.S. Croplands for Biofuels Increases Greenhouse Gases Through Emissions from Land-Use Change; Science 2008, 319, 1238-1240; doi: 10.1126/science.1151861. 5. Dale, B. Sound Policy Needs Sound Science; The Washington Times, November. 26, 2008. 6. Wang, M.; Wu, M.; Huo, H. Life-Cycle Energy and Greenhouse Gas Emission Impacts of Different Corn Ethanol Plant Types; Environ. Res. Lett. 2007, 2, 024001 ; doi:10.1088/1748-9326/2/2/024001. 7. See Lynd, L.R. et al.The Role of Biomass in America’s Energy Future: Framing the Analysis; Biofuels, Bioprod. Bioref. 2009, 3, 113–123; doi: 10.1002/bbb.134; and Laser, M. et al. Comparative Analysis of Efficiency, Environmental Impact, and Process Economics for Mature Biomass Refining Scenarios; Biofuels, Bioprod. Bioref. 2009, 3, 247–270; doi: 10.1002/bbb.136. 8. Tate, E.D.; Harpster, M.O.; Savagian, P.J. The Electrification of the Automobile: From Conventional Hybrid to Plug-in Hybrids to Extended Range Electric Vehicles. Presented at SAE 2008 World Congress, Detroit, MI, 2008; SAE-2008-01-0458. awma.org Copyright 2009 Air & Waste Management Association may 2009 em 29