Extreme Hybrid™ Technology
Extreme Hybrid™ Drive Train Overview
The Extreme Hybrid™ will be the first practical drive train for a Plug-in Hybrid Vehicle. Its two-part energy storage system combines a Lithium-ion battery pack with a bank of ultracapacitors. This “hybrid within a hybrid” energy storage system exploits the strengths of li-ion batteries (light weight and high energy density) and ultracapacitors (small size and high power density). Batteries alone, have high energy density but they must be greatly oversized in today’s hybrid vehicles to avoid deep discharges. Battery-only hybrids also require a powerful internal combustion engine for hill climbing and acceleration. (Plug-in Hybrids compared here.)
Adding ultracapacitors with their high power density and high cycle life allows the Extreme Hybrid™ Plug-in to achieve top speeds and rapid acceleration in electric-only mode equal to a conventional hybrid. The Extreme Hybrid™ design allows for a smaller internal combustion engine while preserving high vehicle performance. For a typical daily commute of 40 miles round trip, an Extreme Hybrid™ vehicle will not use its internal combustion engine at all.
Extreme Hybrid™ Drive Train
The Extreme Hybrid™ Plug-in drive train is composed of five primary subsystems: (1) advanced lithium batteries recharged at night with off-peak power from the grid; (2) Fast Energy Storage™ using ultracapacitors for acceleration and regenerative braking; (3) advanced power electronics and control software; (4) flex-fuel capable internal combustion engine; and (5) electric traction motor and generator. In miles per petroleum gallon, an XH™ plug-in car is expected to be capable of 250 MPPG and an XH™ SUV is expected to achieve 150 MPPG.
How the XH™ will differ from Conventional Hybrids
The Extreme Hybrid™ vehicle will differ from today’s popular hybrids in several ways. The most important are the increased capacity of the battery, the ability to recharge the battery from the electric power grid, and, equally important, the presence of a second Fast Energy Storage™ component that will enable rapid acceleration and greater regenerative braking capability. The Extreme Hybrid™ requires the seamless transfer of power between a number of different devices, including traction motors, generator, charging system, and ancillary loads. The system faces integration and control issues that AFS Trinity has already addressed and mastered in the development of fast energy storage and power management systems. The technologies crucial to the Extreme Hybrid™ are batteries, Fast Energy Storage™, and power electronics.
How the Extreme Hybrid™ Can Achieve 250 MPG
Extreme Hybrid™ Energy Storage Detail
AFS Trinity has selected Lithium-ion battery technology for its minimum weight per unit of stored energy. The life of lithium batteries, however, is shortened by high current discharge and recharge during acceleration and braking. The presence of a high power density ultracapacitor will buffer the battery from these high current events and prolong battery life to a minimum ten year, 150,000 mile life in an Extreme Hybrid™ SUV.
Li-ion battery technology has advanced dramatically over the past ten years, and this rate of advance is expected to continue, bringing it to a high stage of development by the year 2010, concurrent with the completion of development of the Extreme Hybrid™. Power Electronics prices have dropped 15% per year for a decade, and this trend is expected to continue, which will also contribute to Extreme Hybrid™ vehicle affordability in 2010. Ultracapacitor prices have dropped a factor of two every two years for the past six years, and the price drop is projected to continue through 2010 and beyond.
!
--- Xcel Energy Study: with a Smart Grid, Plug-in Hybrid Electric
Vehicles Could Have System Benefits http://www.xcelenergy.com/ (click
Newsroom, News Releases)(PHEVs with a 9 kilowatt-hour battery could
reduce overall CO2 vehicles emissions by 50 percent; save $450 in fuel
costs each year with smart-grid technologies; send excess electricity
pack to grid; lead to better use of renewable energy sources.) (2/21/07)
Plug-in hybrids: the way to reduce emissions and foster energy independence
Their commercial success hinges on an aggressive development and marketing effort by a major automaker.
By Steven Letendre, Paul Denholm, and Peter Lilienthal
POULTNEY, VT.; AND GOLDEN, COLO.
We have within our grasp automotive technology to reduce US oil dependence dramatically. Its development and use, however, requires a coordinated effort between the nation's public utilities and car manufacturers. Now is the time for the electric power industry to apply its expertise and clout to the development of new automotive technology that relies to a greater degree on domestic energy resources.
The prospect of millions of vehicles plugging into the nation's electric grid in coming decades has never been better. In 2005, the number of hybrid electric vehicles (HEV) reached 1.2 percent of new cars sold in the United States, more than doubling the number of the previous year. Spotting a trend, carmakers are rushing to bring hybrids into their dealers' showrooms.
It would be a natural step – and a great benefit – to allow hybrids to charge their batteries via the electric grid. Indeed, there is a growing movement to bring plug-in hybrids to market. This is driven by the economic and national-security benefits that result from displacing gasoline with electricity. Dozens of businesses, utilities, municipal governments, and environmental groups have joined a grass-roots campaign called Plug-In Partners to demonstrate to automobile manufacturers that a national market exists for plug-in vehicles.
While there are no commercially available plug-in hybrids now, prototypes have been built and tested, most notably at the University of California, Davis, and by a collaboration between the Electric Power Research Institute and DaimlerChrysler.
In addition, three start-up firms offer conversion kits for hybrid cars to allow grid charging of the on-board battery pack. These offer the potential to almost double a hybrid's fuel efficiency to approximately 100 miles per gallon.
This past summer, Jim Press, president of Toyota's North American subsidiary, announced that the company was looking at developing a plug-in hybrid that travels farther without gasoline than current hybrid models. Toyota is the leading manufacturer of hybrids, selling more than half of those purchased in the US in 2005. Both Ford and General Motors also have recently announced development plans for plug-in vehicles based on a variety of platforms.
We believe that commercial success of plug-in hybrids hinges on an aggressive development and marketing effort by a major automaker. Equally important is support from the electric power industry to facilitate a smooth transition by allowing electricity to serve as a growing energy source for transportation.
On one dollar's worth of electricity, a car can travel the same distance as it would on one gallon of gasoline. The electricity would cost even less if users could buy it at lower, off-peak prices.
We performed simulations for the impact of plug-in hybrids on electric load in six different regions of the nation. We found that the current and planned electric-power infrastructure in America can meet the increased demand from plug-in hybrids.
In addition, during the 90 percent of the time that most vehicles are sitting parked, electric-drive cars could actually supply power to the electric grid through a concept known as "vehicle to grid" technology or V2G for short. The V2G concept envisions the use of a bidirectional charger that allows electricity to flow into a vehicle's battery for charging, or lets stored electricity in the battery flow back onto the power grid. This could increase grid reliability and generate hundreds of dollars of revenue per year for hybrid owners.
While the cost of electricity from electric-drive vehicles is too high to make it attractive for utilities to buy during "baseload" power times, it is quite marketable for "peak power" times and for what are called "spinning and regulation reserves." There are regulatory issues to overcome – the rules are typically written to accommodate incumbent technologies – but this concept can be made into reality.
And the additional cost of installing V2G technology in hybrid cars would be minimal when amortized over a fleet of tens of thousands of vehicles.
Plug-in hybrid automobiles represent an exciting opportunity to create greater energy independence and reduce harmful emissions. As the electric-supply mix becomes "greener," this affords additional environmental benefits.
It is time for the nation's public utilities to lend their voices to the growing chorus of stakeholders calling for the major auto manufacturers to deliver a commercial plug-in hybrid to the market. The utilities also should begin designing the vehicle-grid interface, proceed with vehicle-to-grid demonstration projects, and develop business models that can profitably exploit the emerging V2G potential.
• Steven Letendre is associate professor of business, economics, and the environment at Green Mountain College in Poultney, Vt. Paul Denholm is a senior energy analyst and Peter Lilienthal is senior economist at the US Department of Energy's National Renewable Energy Laboratory. This article is adapted from a technical paper they wrote in the December 2006 issue of Public Utilities Fortnightly.
1. What Are Plug-In Hybrids?
How does this sound: 100+ MPG in a regular vehicle?
We can achieve that -- today -- with a plug-in hybrid (PHEV). A PHEV is essentially a regular hybrid with an extension cord. You can fill it up at the gas station, and you can plug it in to any 120-volt outlet. It's like having a second fuel tank that you always use first -- only you fill up at home, from a regular outlet, at an equivalent cost of under $1/gallon.
You don't have to plug it in. But when you do, your car essentially becomes an electric vehicle with a gas-tank backup. So you'll have a cleaner, cheaper, quieter car for your local travel, and the gas tank is always there should you need to drive longer distances.
But wait, there's more:
- If your driving is mostly local, you'd almost never need to gas-up.
- Lifetime service costs are lower for a vehicle that is mainly electric.
- A PHEV can provide power to an entire home in the case of an outage; A fleet of PHEVs could power critical systems during emergencies.
2. Plug-In Hybrids Are Cleaner (Even on a Coal Grid) [
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CA, NY, MA and other states have had Zero-Emission Vehicle programs since the early 1990s because battery electric vehicles in those states, taking into account power plants, are far cleaner than gasoline cars in reducing urban air pollution and smog. The comparison keeps being raised, though studies are conclusive:
The "well-to-wheel" emissions of electric vehicles are lower than those from gasoline internal combustion vehicles. California Air Resources Board studies show that battery electric vehicles emit at least 67% lower greenhouse gases than gasoline cars -- even more assuming renewables. A PHEV with only a 20-mile all-electric range is 62% lower (see printed page 95 in the 2004 study).
Nationally, two government studies have found PHEVs would result in large reductions even on the national grid (50% coal). The GREET 1.6 model in 2001 by the DOE's Argonne National Lab estimates hybrids reduce greenhouse gases by 22%, and plug-in hybrids by 36% (see table 2). An Argonne researcher reached consensus with researchers from other national labs, universities, the Air Resources Board, automakers, utilities and AD Little to estimate in July 2002 that PHEVs using nighttime power reduce greenhouse gases by 46 to 61 percent. This is summarized in slide 11 at the November 2003 presentation by EPRI. For more in the media on this, see also the May 2, 2005 followup to the April 11 Business Week story
Only PHEVs and battery EVs get cleaner as they get older - because the electric grid gets cleaner every decade. Plus more people are installing rooftop solar photovoltaic systems, and clean wind power is vastly expanding nationally (see study by eminent environmentalist Lester Brown cited at CalCars Kudos). Finally, looking at the non-electric fuel, instead of using gasoline for long-trips, PHEVs could run on bio-diesel, cellulose ethanol, or other bio-fuels to further reduce greenhouse gases.
PHEVs will generally recharge at night using excess power from plants that can't shut down completely -- so they don't add to the peak load. PHEVs might one day actually help reduce it by providing power from parked PHEVs' batteries during daytime hours (see Vehicle-to-Grid in our FAQ).
3. PHEVs Are Cheaper to Run and Cheaper to Maintain [
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1/4 the Price?
At $3 for a gallon of gas, driving a non-hybrid car costs 8-20 cents/mile (depending on MPG).
With a PHEV, your electric local travel drops to as little as 2-4 cents/mile.
We say above that you can fill up your "electric tank" for less than $1/gallon. How? Using the average U.S. electricity rate of 9 cents per kilowatt-hour (kWh),
30 miles of electric driving will cost 81 cents. If we optimistically assume the average US fuel economy is 25 miles per gallon, at $3.00 gasoline this equates to
75 cents a gallon for equivalent electricity. Compared to a regular hybrid's real-world 45 miles per gallon, it's effectively $1.20/gallon.
PHEVs are meant to plug-in at night. In many areas of the country, overnight power is available at a lower cost. As PHEVs start to enter the marketplace, we'll see increasing support from electric utilities, as they'll offer reduced nighttime rates to incentivize off-peak charging. In some areas where wind and hydropower is wasted at night, the rate can be as low as 2-3 cents per kWh. That's 20-25 cents a gallon.
Why Pay More for a PHEV?
Cost increments for a plug-in hybrid compact vehicle will be 10-20% more than a regular hybrid: $2000-3000 extra for a sedan; $5000 for an SUV. CalCars' mission is to narrow the cost gap through incentives, subsidies and rebates while making the case for paying extra to gain access to car-pool lanes, spend less time at gas stations, get home backup power, lower maintenance costs, and, most importantly, benefit society by reducing oil imports, greenhouse gases and pollution.
People routinely pay more for such options as sunroofs, automatic transmissions, V8 engines and leather seats. These are "features" -- and no one asks about the payback. A JD Power survey shows buyers will pay more for cars with the "environmental feature." How much more? The high demand for the Honda Civic hybrid tell us it's at least $3,000.
The Bottom Line
Plug-ins cost more mainly because batteries are expensive. But battery technology is improving steadily (especially lithium-ion, with nano-technology versions also looking promising), and in large quantities current options are acceptable.
Plug-ins cost more mainly because batteries are expensive. But battery technology is improving steadily (especially lithium-ion, with nano-technology versions also looking promising), and in large quantities current options are acceptable.
Regardless, a 2003
EPRI battery study shows that mass-produced
PHEVs have already reached lifecycle cost parity with gas-powered vehicles -- using gas prices from three years ago! This means the more maintenance-free electrical systems of PHEVs offset the initial higher cost of batteries.
4. PHEVs Are Domestically-Powered [
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The nationwide electrical grid is only 3% petroleum-fueled, whereas transportation is almost completely powered by oil -- 60% of which comes from foreign sources (and growing). Adoption of plug-in hybrids will transfer the overwhelming majority of our miles driven to nearly oil-free electricity. If all vehicles were plug-in hybrids we would cut our oil needs by 55%, nearly enough to eliminate foreign sources altogether.
The winning combination from an environmental and national-security perspective is the flexible-fuel PHEV -- one that runs on biofuels, cellulosic ethanol, methanol, or alternative liquid fuel in place of gasoline. This will reduce the transportation sector's use of oil to almost zero -- and cut the United States' annual oil needs by 2/3.
A growing coalition of bipartisan leaders and national security experts has emerged in vocal support of plug-in hybrids (and flexible-fuel PHEVs). These include former Secretary of State George Shultz, former CIA Director R. James Woolsey, former National Security Advisor Robert McFarlane, and senators and congressmen.
5. PHEVs Already Exist [
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We use this section to track existing plug-in hybrids, to prove definitively that PHEVs rely exclusively on existing technology -- no new advances are required. PHEV conversions are emerging at a frenzied rate (see the frequency of CalCars-News postings), to the point where it's no longer feasible to track every instance of a PHEV. In short:
- Many automakers have built PHEVs in private workshops, and DaimlerChrysler has publicly tested PHEV prototypes. They are converting up to 40 15-passenger Mercedes commercial vans into PHEVs, with some vehicles using NiMH and others advanced lithium-ion batteries, plus diesel and gasoline engines. The program is in cooperation with California's Electric Power Research Institute (EPRI), South Coast Air Quality Management District, and Southern California Edison. See the press release, EPRI announcement and Daimler's description (with graphics).
- The advanced hybrid vehicle research center at University of California-Davis (founded and directed by CalCars advisor Prof. Andy Frank) has converted nine sedans and SUVs into PHEVs that have repeatedly won prizes in US Energy Department-sponsored "FutureTruck" competitions. Dr. Frank, widely known as the "Father of the Plug-In Hybrid," has been working on PHEVs for thirty years, and building them with students for more than a decade.
- CalCars produced the world's first plug-in Prius (the PRIUS+) in 2004. Since then a number of companies have emerged to offer conversions for sale to consumers and fleet buyers, and CalCars has worked to support a growing open-source conversion movement.
- In 2003-04, the US Marine Corps demonstrated a diesel-electric PHEV-20 HUMVEE. (The military likes the silent, zero-heat "footprint" in all-electric mode, and appreciates saving fuel that can cost well over $100/gallon to deliver to front lines.) This advanced Shadow RST-V (Reconnaissance, Surveillance and Targetting Vehicle PHEV, built by General Dynamics, uses lightweight lithium-ion batteries and motors in four wheel hubs. See details and photos and more descriptions.
- Long Island, NY has converted a city bus to a plug in hybrid with 40 miles of all-electric range. Many more heavy-duty vehicle conversions (including three recycling dump-trucks that will run in "silent" mode for pickups) are in progress.
See CalCars-News for the latest news on PHEV development, and Where PHEVS Are for a chronological list of Toyota Prius conversions. For a more detailed history of plug-in hybrids, see Plug-In Hybrids: State of Play, History and Players.
Ford to debut Edge hybrid with fuel cell Ford's Flexible Series Hybrid Edge will plug in to recharge. (Manuel Balce Ceneta/Associated Press)
By Associated Press | January 23, 2007
WASHINGTON -- Ford Motor Co. is joining the list of automakers working on a plug-in hybrid -- with a twist. It combines the convenience of plugging in your car with a zero-emissions hydrogen fuel cell.
Ford is to display today what it calls the world's first drivable fuel cell hybrid-electric vehicle with plug-in capability. Called the Flexible Series Hybrid Edge, it represents the latest offering from automakers hoping to stake a claim to the next generation of highly efficient, alternative vehicles.
Gerhard Schmidt, vice president of research and advanced engineering, said the vehicle, based on the Edge crossover platform, gives Ford "the ultimate in flexibility in researching advanced propulsion technology."
"We could take the fuel cell power system out and replace it with a downsized diesel, gasoline engine, or any other powertrain connected to a small electric generator to make electricity like the fuel cell does now," Schmidt said.
Ford was showing the plug-in fuel cell at the Washington Auto Show, where lawmakers and government officials were viewing a number of advanced vehicle technologies. The show opens for media previews on the eve of President Bush's State of the Union address, which is expected to include energy proposals of concern to the auto industry.
Several automakers have been working on similar technologies. General Motors Corp. will display the Chevrolet Volt, a plug-in electric car recently unveiled in Detroit that has a range of 40 miles with the battery and more than 600 miles with a gas engine.
DaimlerChrysler AG has been pursuing plug-in hybrids and said Friday it would expand its test fleet in the United States to more than 20 Dodge Sprinter vans. Company chairman, Dieter Zetsche, and Chrysler Group chief executive Tom LaSorda were expected to discuss clean diesel technology at the auto show today.
Volkswagen AG will be showing the Golf GT TSI for the first time in the United States. The vehicle's supercharged gasoline engine has 170 horsepower while garnering 40 miles per gallon city and 48 m.p.g. highway. VW estimates 638 miles on one tank of fuel.
Ford's plug-in hybrid Edge operates in 'battery only' mode for the first 25 miles, moving at speeds of up to 85 miles per hour. When the battery is depleted to 40 percent, it seamlessly shifts to the fuel cell mode, which recharges the battery for 200 more miles of range.
Plug-In Diesel Hybrid Talk By Reed Benet UC Davis
In Favor of the Plug-in Hybrid Diesel
"Google Tech Talks September 20, 2006" has an excellent presentation, Better Than Ethanol? BTL in plug-in hybrid diesel vehicles, by Reed Benet a PhD student at UC Davis, Institute of Transportation Studies, that makes a strong case for the plug-in hybrid diesel vehicle. The plug-in is combined with biomass-to-liquid diesel fuels, (versus ethanol, cellulosic or otherwise) and is presented as the best medium-to long-term solution for our dependence on foreign oil and our transportation accelerated global warming. Benet also provides a whirlwind historical and prospective tour of transportation, vehicles, fuels, infrastructure, business models, motivations and options.
The presentation emphasized that the diesel is 30% more efficient than the gasoline engine, that the net energy balance for gasification/Fischer-Tropsch process is 10x vs much lower values for conventional biodiesel or ethanol and that the technology is much closer to reality and less costly than hydrogen/fuel cell cars. The added expense of the vehicles can be justified by the V2G capability of the vehicles and the fact that they can be charged at night using off-peak power.
Another claimed advantage of this model is that the big-oil companies might be interested in it and could provide the necessary capital investment and development know how, because of the scale of size and because they can add prorietary technology to the BTL process. The oil companies are able to afford the longer payout period of the BTL process, compared to that of the conventional biofuels processes and thus take advantage of the greater efficiency. As an example Shell has invested in the Choren gasification process.
1. Mr. Benet touches on the importance of weight in improving mpg, but then seems to forget about this. He points out it took 100 years before lighter metal made automobiles possible. New battery technology along with lighter, stronger carbon fiber bodies makes EVs possible and gas/diesel unnecessary for light trucks and cars.
2. Current HEV technology is described in terms of nickel-metal-hydride battery technology. They are all moving to Lithium Ion technolgy with twice the energy density AND twice the power density. This means double the all electric range AND freeway compatable accelleration, respectively...if composite carbon construction can be made cost effective this is disruptive tech.
3. Yes, it is true that current PHEVs don't have sufficient payback on fuel savings...BUT consider that Toyota is targeting 100 mpg using Li Ion and planning to reduce the price. This will be true for all automakers, big and small, that jump into the game with current technology. Also, don't forget "the lesson of the Prius": Build for the small market ahead of time and you have a proven product when demand increases.
There is a PHEV/EV market out there at premium prices.
(Looks like Mitsubishi will make a "True" PHEV in the near future.)
December 25, 2006
New York's Plug-in Hybrid Inititive
Hymotion_plugin New York state has embarked on a $10 million program to convert 574 hybrid vehicles in the state fleet to be plug-in hybrids (PHEVs). The converted vehicles will be able to achieve significantly higher mileage than the hybrids, in the range of 100 mpg. These vehicles operate on emissions-free battery power, for a significant portion of their operating time, with lower emissions of harmful pollutants, including greenhouse gases. This high mileage vehicle plan is part of the governor’s plan to reduce dependence on imported energy.
On December 20 the state showcased the first vehicle delivered under this program, a Prius using A123 batteries that was converted to a PHEV by Hymotion.
The vehicle is the first one delivered in phase one of a two-phase program conducted by the New York State Energy Research and Development Authority (NYSERDA). Phase One plans call for the conversion of two Priuses, three Ford Escape SUVs and a Honda Civic for technical evaluation.
The second phase of the program will be to bulk-purchase the selected technologies for installation on the remaining hybrids in the State fleet. Phase One, with design and prototyping will cost up to a million dollars; Phase Two involves bulk conversions and is budgeted for up to $9 million.
Plug-in Hybrids Stabalize Electric Grid
Technology Review has a nice roundup on the advantages of plug-in hybrids (PHEVs), pointing out how the vehicles could help stabilize the grid if they were charged during low demand periods. Some key excerpts from Technology Review:
Such a system could be further optimized by using smart chargers and other electronics. This system would include a charger that runs on a timer, charging cars only during off-peak hours. Researchers at Pacific Northwestern National Laboratory (PNNL) are taking this a step further with smart chargers that use the Internet to gather information about electricity demand. Utilities could then temporarily turn off chargers in thousands of homes or businesses to keep the grid from crashing after a spike in demand.
The next step would be to add smart meters that would track electricity use in real time and allow utilities to charge more for power used during times of peak demand, and less at off-peak hours. Coupled with such a system, the PNNL smart charger could ensure that the plug-in batteries are charged only when the electricity is at its cheapest, saving consumers money.
But what many experts are excited about now is a concept called "vehicle-to-grid," often abbreviated V2G. ... In this kind of system, each vehicle would have its own IP address so that wherever it is plugged in, the cost of the energy it uses to recharge would be billed to the owner. With the right equipment, the car could also return energy to the grid, giving the owner credit. Mock-ups of such systems have already been tested ...
Mileage From Megawatts: Study Finds Enough Electric Capacity To 'Fill Up' Plug-in Vehicles
Science Daily — If all the cars and light trucks in the nation switched from oil to electrons, idle capacity in the existing electric power system could generate most of the electricity consumed by plug-in hybrid electric vehicles. A new study for the Department of Energy finds that "off-peak" electricity production and transmission capacity could fuel 84 percent of the country's 220 million vehicles if they were plug-in hybrid electrics.
Researchers at DOE's Pacific Northwest National Laboratory also evaluated the impact of plug-in hybrid electric vehicles, or PHEVs, on foreign oil imports, the environment, electric utilities and the consumer.
"This is the first review of what the impacts would be of very high market penetrations of PHEVs, said Eric Lightner, of DOE's Office of Electric Delivery and Energy Reliability. "It's important to have this baseline knowledge as consumers are looking for more efficient vehicles, automakers are evaluating the market for PHEVs and battery manufacturers are working to improve battery life and performance."
Current batteries for these cars can easily store the energy for driving the national average commute - about 33 miles round trip a day, so the study presumes that drivers would charge up overnight when demand for electricity is much lower.
Researchers found, in the Midwest and East, there is sufficient off-peak generation, transmission and distribution capacity to provide for all of today's vehicles if they ran on batteries. However, in the West, and specifically the Pacific Northwest, there is limited extra electricity because of the large amount of hydroelectric generation that is already heavily utilized. Since more rain and snow can't be ordered, it's difficult to increase electricity production from the hydroelectric plants.
"We were very conservative in looking at the idle capacity of power generation assets," said PNNL scientist Michael Kintner-Meyer. "The estimates didn't include hydro, renewables or nuclear plants. It also didn't include plants designed to meet peak demand because they don't operate continuously. We still found that across the country 84 percent of the additional electricity demand created by PHEVs could be met by idle generation capacity."
"Since gasoline consumption accounts for 73 percent of imported oil, it is intriguing to think of the trade and national security benefits if our vehicles switched from oil to electrons," added PNNL energy researcher Rob Pratt. "Plus, since the utilities would be selling more electricity without having to build more plants or power lines, electricity prices could go down for everyone."
Lightner noted that "the study suggests the idle capacity of the electric power grid is an underutilized national asset that could be tapped to vastly reduce our dependence on foreign oil."
The study also looked at the impact on the environment of an all-out move to PHEVs. The added electricity would come from a combination of coal-fired and natural gas-fired plants. Even with today's power plants emitting greenhouse gases, the overall levels would be reduced because the entire process of moving a car one mile is more efficient using electricity than producing gasoline and burning it in a car's engine.
Total sulfur dioxide emissions would increase in the near term due to sulfur content in coal. However, urban air quality would actually improve since the pollutants are emitted from power plants that are generally located outside cities. In the long run, according to the report, the steady demand for electricity is likely to result in investments in much cleaner power plants, even if coal remains the dominant fuel for our electricity production.
"With cars charging overnight, the utilities would get a new market for their product. PHEVs would increase residential consumption of electricity by about 30 - 40 percent. The increased generation could lead to replacing aging coal-fired plants sooner with newer, more environmentally friendly versions," said Kintner-Meyer.
"The potential for lowering greenhouse gases further is quite substantial because it is far less expensive to capture emissions at the smokestack than the tailpipe. Vehicles are one of the most intractable problems facing policymakers seeking to reduce greenhouse gas emissions," said Pratt.
Finally, the study looked at the economic impact on consumers. Since, PHEVs are expected to cost about $6,000 to $10,000 more than existing vehicles - mostly due to the cost of batteries -- researchers evaluated how long it might take owners to break even on fuel costs. Depending on the price of gas and the cost of electricity, estimates range from five to eight years - about the current lifespan of a battery. Pratt notes that utilities could offer a lower price per kilowatt hour on off-peak power, making PHEVs even more attractive to consumers.
Adding "smart grid" communications technology to ensure the vehicles only charge during off-peak periods and to provide immediate, remote disconnect of chargers in event of problems in the power grid would make them attractive to utilities.
Note: This story has been adapted from a news release issued by Pacific Northwest National Laboratory.
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