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A hydrogen vehicle is a vehicle that uses hydrogen as its onboard fuel for motive power. Hydrogen vehicles include hydrogen fueled space rockets, as well as automobiles and other transportation vehicles. The power plants of such vehicles convert the chemical energy of hydrogen to mechanical energy either by burning hydrogen in an internal combustion engine, or by reacting hydrogen with oxygen in a fuel cell to run electric motors. Widespread use of hydrogen for fueling transportation is a key element of a proposed hydrogen economy.
Hydrogen fuel does not occur naturally on Earth and thus is not an energy source; rather it is an energy carrier. It is most frequently made from methane or other fossil fuels, but it can be produced using sources (such as wind, solar, or nuclear) that are intermittent, however the conversion loss to chemical energy makes the approach uneconomical on a large scale. Integrated wind-to-hydrogen (power to gas) plants, using electrolysis of water, are exploring technologies to deliver costs low enough, and quantities great enough, to compete with traditional energy sources. There are various ways to produce hydrogen fuel such as: natural gas, coal, nuclear power, and renewable resources. By use of thermochemical processes one can produce hydrogen from biomass, coal, natural gas and petroleum. Production of hydrogen electrolytically can also be demonstrated experimentally for power generated by use of sunlight, wind and nuclear sources. In addition to this, sunlight alone can drive photolytic production of hydrogen from water by use of advanced photocatalytic water splitting and photo biological processes however none of these approaches can compete with the low cost and abundance of natural gas produced by the hydraulic fracturing of shales.
Many companies are working to develop technologies that might efficiently exploit the potential of hydrogen energy for use in motor vehicles. As of November 2013[update] there are demonstration fleets of hydrogen fuel cell vehicles undergoing field testing including the Chevrolet Equinox Fuel Cell, Honda FCX Clarity, Hyundai ix35 Fuel Cell and Mercedes-Benz B-Class F-Cell. The hope that was widely promoted for hydrogen as an energy currency was that, hydrogen prepared without using fossil fuel inputs, vehicle propulsion would not contribute to carbon dioxide emissions, however this has proven to be uneconomical in light of the developments of fracking. The drawbacks of hydrogen use are high carbon emissions intensity when produced from natural gas of over 14 kg CO2 per kg of hydrogen, capital cost burden, low energy content per unit volume, low performance of fuel cell vehicles compared with gasoline vehicles, production and compression of hydrogen, and the large investment in infrastructure that would be required to fuel vehicles.
Buses, trains, PHB bicycles, canal boats, cargo bikes, golf carts, motorcycles, wheelchairs, ships, airplanes, submarines, and rockets can already run on hydrogen, in various forms. NASA used hydrogen to launch Space Shuttles into space. A working toy model car runs on solar power, using a regenerative fuel cell to store energy in the form of hydrogen and oxygen gas. It can then convert the fuel back into water to release the solar energy. Since the advent of hydraulic fracturing the key concern for environmentalists with hydrogen fuel cell vehicles is consumer and public policy confusion that could result adoption of natural gas powered hydrogen vehicles with heavy hidden emissions to the detriment of environmentally friendly transportation.
The current land speed record for a hydrogen-powered vehicle is 286.476 miles per hour (461.038 km/h) set by Ohio State University's Buckeye Bullet 2, which achieved a "flying-mile" speed of 280.007 miles per hour (450.628 km/h) at the Bonneville Salt Flats in August 2008. For production-style vehicles, the current record for a hydrogen-powered vehicle is 207.297 miles per hour (333.612 km/h) set by a prototype Ford Fusion Hydrogen 999 Fuel Cell Race Car at Bonneville Salt Flats in Wendover, Utah in August 2007. It was accompanied by a large compressed oxygen tank to increase power.
Many automobile companies are currently researching the feasibility of commercially producing hydrogen cars, and some have introduced demonstration models in limited numbers (see list of fuel cell vehicles). At the 2012 World Hydrogen Energy Conference, Daimler AG, Honda, Hyundai and Toyota all confirmed plans to produce hydrogen fuel cell vehicles for sale by 2015. General Motors said it had not abandoned fuel-cell technology and still plans to introduce hydrogen vehicles like the GM HydroGen4 to retail customers by 2015. Charles Freese, GM’s executive director of global powertrain engineering, stated that the company believes that both fuel-cell vehicles and battery electric vehicles are needed for reduction of greenhouse gases and reliance on oil.
In December 2012 Toyota announced its plans to limit its all-electric car development and instead concentrate on the development and launch of a fuel cell vehicle by 2015. In October 2013 Toyota announced it had reduced the cost of the fuel cell system in its next hydrogen-powered car by almost US$1 million and expects to introduce a hydrogen mid-size sedan at a price of less than US$100,000 by 2015. Toyota plans to launch its first production fuel cell vehicle, the Toyota FCV, in 2015. The car is expected to have a range of 430 mi (690 km) and to take about three minutes to refill its hydrogen tank. It is expected to be available first in Japan, and then in California, mainly the Los Angeles area, due to the availability there of hydrogen fueling stations. The expected cost in Japan is about 7 million yen ($69,000).
In 2009, Nissan started testing a new FC vehicle in Japan. Daimler has introduced its B-class demonstration FC vehicle. In 2011, Hyundai introduced its Blue2 ("Blue Square") fuel cell electric vehicle (FCEV), and stated that it plans to have FCEVs available for sale by 2014. Honda stated in 2009 that it could start mass-producing vehicles based on its FCX Clarity concept car by the year 2020 and in 2009 stated that it saw hydrogen fuel cells as "a better long term bet than batteries and plug-in vehicles". In December 2010, however, it introduced the Honda Fit EV, an all-electric car version of the gasoline-powered Fit, using elements of its hydrogen engine design, stating that the "industry trend seems to be focused on the battery electric vehicle".
In 2012, Lux Research, Inc. issued a report that stated: "The dream of a hydrogen economy ... is no nearer." It concluded that "Capital cost, not hydrogen supply, will limit adoption to a mere 5.9 GW" by 2030, providing "a nearly insurmountable barrier to adoption, except in niche applications". Lux's analysis concluded that by 2030, the PEM stationary market will reach $1 billion, while the vehicle market, including forklifts, will reach a total of $2 billion.
Hydrogen was first stored in roof mounted tanks, although models are now incorporating onboard tanks. Some double deck models use between floor tanks.
Pearl Hydrogen Power Sources of Shanghai, China, unveiled a hydrogen bicycle at the 9th China International Exhibition on Gas Technology, Equipment and Applications in 2007.
ENV develops electric motorcycles powered by a hydrogen fuel cell, including the Crosscage and Biplane. Other manufacturers as Vectrix are working on hydrogen scooters. Finally, hydrogen fuel cell-electric hybrid scooters are being made such as the Suzuki Burgman Fuel cell scooter. and the FHybrid. The Burgman received "whole vehicle type" approval in the EU. The Taiwanese company APFCT conducted a live street test with 80 fuel cell scooters for Taiwans Bureau of Energy.
Companies such as Boeing, Lange Aviation, and the German Aerospace Center pursue hydrogen as fuel for manned and unmanned airplanes. In February 2008 Boeing tested a manned flight of a small aircraft powered by a hydrogen fuel cell. Unmanned hydrogen planes have also been tested. For large passenger airplanes however, The Times reported that "Boeing said that hydrogen fuel cells were unlikely to power the engines of large passenger jet airplanes but could be used as backup or auxiliary power units onboard."
In Britain, the Reaction Engines A2 has been proposed to use the thermodynamic properties of liquid hydrogen to achieve very high speed, long distance (antipodal) flight by burning it in a precooled jet engine.
A HICE forklift or HICE lift truck is a hydrogen fueled, internal combustion engine-powered industrial forklift truck used for lifting and transporting materials. The first production HICE forklift truck based on the Linde X39 Diesel was presented at an exposition in Hannover on May 27, 2008. It used a 2.0 litre, 43 kW (58 hp) diesel internal combustion engine converted to use hydrogen as a fuel with the use of a compressor and direct injection.
A fuel cell forklift (also called a fuel cell lift truck or a fuel cell forklift) is a fuel cell powered industrial forklift truck. In 2013 there were over 4,000 fuel cell forklifts used in material handling in the US. Only 500 of these received funding from DOE in 2012. As of 2013[update], fuel cell fleets are being operated by several number of companies, including Sysco Foods, FedEx Freight, GENCO (at Wegmans, Coca-Cola, Kimberly Clark, and Whole Foods), and H-E-B Grocers. A total of 30 fuel cell forklifts with Hylift were demonstrated in Europe and extended it with HyLIFT-EUROPE to 200 units. With other projects in France and Austria. Pike Research stated in 2011 that fuel-cell-powered forklifts will be the largest driver of hydrogen fuel demand by 2020.
PEM fuel-cell-powered forklifts provide significant benefits over both petroleum forklifts as they produce no local emissions, and as compared with electric vehicles, the forklifts can work for a full 8-hour shift on a single tank of hydrogen, can be refueled in 3 minutes and have a lifetime of 8–10 years. Fuel-cell-powered forklifts are often used in refrigerated warehouses as their performance is not degraded by lower temperatures. Most fuel cells used for material handling purposes are powered by PEM fuel cells, although some DMFC forklifts are coming onto the market. In design the FC units are often made as drop-in replacements.
Many large rockets use liquid hydrogen as fuel, with liquid oxygen as an oxidizer. An advantage of hydrogen rocket fuel is the high effective exhaust velocity compared to kerosene/LOX or UDMH/NTO engines. According to the Tsiolkovsky rocket equation, a rocket with higher exhaust velocity needs less propellant mass to achieve a given change of speed. Before combustion, the hydrogen runs through cooling pipes around the exhaust nozzle to protect the nozzle from damage by the hot exhaust gases.
A disadvantage of LH2/LOX engines are the low density and low temperature of liquid hydrogen, which means bigger and insulated and thus heavier fuel tanks are needed. This increases the rocket's structural mass which reduces its delta-v significantly. Another disadvantage is the poor storability of LH2/LOX-powered rockets: Due to the constant hydrogen boil-off, the rocket can only be fueled shortly before launch, which makes cryogenic engines unsuitable for ICBMs and other rocket applications with the need for short launch preparations.
Overall, the delta-v of a hydrogen stage is typically not much different from that of a dense fuelled stage, however, the weight of a hydrogen stage is much less, which makes it particularly effective for upper stages, since they are carried by the lower stages. For first stages, dense fuelled rockets in studies may show a small advantage, due to the smaller vehicle size and lower air drag.
Liquid hydrogen and oxygen were also used in the Space Shuttle to run the fuel cells that power the electrical systems. The byproduct of the fuel cell is water, which is used for drinking and other applications that require water in space.
Hydrogen internal combustion engine cars are different from hydrogen fuel cell cars. The hydrogen internal combustion car is a slightly modified version of the traditional gasoline internal combustion engine car. These hydrogen engines burn fuel in the same manner that gasoline engines do.
Francois Isaac de Rivaz designed in 1807 the first hydrogen-fueled internal combustion engine. Paul Dieges patented in 1970 a modification to internal combustion engines which allowed a gasoline-powered engine to run on hydrogen US 3844262 .
Mazda has developed Wankel engines burning hydrogen. The advantage of using ICE (internal combustion engine) like Wankel and piston engines is the cost of retooling for production is much lower. Existing-technology ICE can still be applied for solving those problems where fuel cells are not a viable solution insofar, for example in cold-weather applications.
Hydrogen fuel cells are relatively expensive to produce, as their designs require rare substances such as platinum as a catalyst. The U.S. Department of Energy (DOE) estimated in 2002 that the cost of a fuel cell for an automobile (assuming high-volume manufacturing) was approximately $275/kW, which translated into each vehicle costing an estimated 100,000 dollars. However, by 2010, DOE estimated the cost had fallen 80% and that automobile fuel cells might be manufactured for $51/kW, assuming high-volume manufacturing cost savings.
The projected cost, assuming a manufacturing volume of 500,000 units/year, using 2012 technology, was estimated by the DOE to be $47/kW for an 80 kW PEM fuel cell. Assuming a manufacturing volume of 10,000 units/year, however, the cost was projected to be $84/kW using 2012 technlogy. The Department of Energy wrote: "Hydrogen fuel cells for cars have never been manufactured at large scale, in part because of the prohibitive price tag. But the DOE estimates that the cost of producing fuel cells is falling fast".
In 2014, Toyota said it would sell its Toyota FCV in Japan for less than $70,000 by April 2015 and that it has brought the cost of the fuel cell system down to 5 percent of the fuel cell prototypes of the last decade.
The problems in early fuel cell designs at low temperatures concerning range and cold start capabilities have been addressed so that they "cannot be seen as show-stoppers anymore". Users in 2014 said that their fuel cell vehicles perform flawlessly in temperatures below zero, even with the heaters blasting, without significantly reducing range.
Hydrogen does not come as a pre-existing source of energy like fossil fuels, but is first produced and then stored as a carrier, much like a battery. A suggested benefit of large-scale deployment of hydrogen vehicles is that it could lead to decreased emissions of greenhouse gases and ozone precursors.
According to the United States Department of Energy, "compared to ICE vehicles using gasoline ... fuel cell vehicles using hydrogen produced from natural gas reduce greenhouse gas emissions by 60%." While methods of hydrogen production that do not use fossil fuel would be more sustainable, currently renewable energy represents only a small percentage of energy generated, and power produced from renewable sources can be used in electric vehicles and for non-vehicle applications.
The challenges facing the use of hydrogen in vehicles include production, storage, transport and distribution. The well-to-wheel efficiency for hydrogen is less than 25%. A study sposored by the U.S. Department of Energy said in 2004 that the well-to-wheel efficiency of gasoline or diesel powered vehicles is even less.
The molecular hydrogen needed as an on-board fuel for hydrogen vehicles can be obtained through many thermochemical methods utilizing natural gas, coal (by a process known as coal gasification), liquefied petroleum gas, biomass (biomass gasification), by a process called thermolysis, or as a microbial waste product called biohydrogen or Biological hydrogen production. 95% of hydrogen is produced using natural gas, and 85% of hydrogen produced is used to remove sulfur from gasoline. Hydrogen can also be produced from water by electrolysis or by chemical reduction using chemical hydrides or aluminum. Current technologies for manufacturing hydrogen use energy in various forms, totaling between 25 and 50 percent of the higher heating value of the hydrogen fuel, used to produce, compress or liquefy, and transmit the hydrogen by pipeline or truck.
Environmental consequences of the production of hydrogen from fossil energy resources include the emission of greenhouse gases, a consequence that would also result from the on-board reforming of methanol into hydrogen. Analyses comparing the environmental consequences of hydrogen production and use in fuel-cell vehicles to the refining of petroleum and combustion in conventional automobile engines do not agree on whether a net reduction of ozone and greenhouse gases would result. Hydrogen production using renewable energy resources would not create such emissions or, in the case of biomass, would create near-zero net emissions assuming new biomass is grown in place of that converted to hydrogen. However the same land could be used to create Biodiesel, usable with (at most) minor alterations to existing well developed and relatively efficient diesel engines. In either case, the scale of renewable energy production today is small and would need to be greatly expanded to be used in producing hydrogen for a significant part of transportation needs. As of December 2008, less than 3 percent of U.S. electricity was produced from renewable sources, not including dams. In a few countries, renewable sources are being used more widely to produce energy and hydrogen. For example, Iceland is using geothermal power to produce hydrogen, and Denmark is using wind.
Hydrogen has a very low volumetric energy density at ambient conditions, equal to about one-third that of methane. Even when the fuel is stored as liquid hydrogen in a cryogenic tank or in a compressed hydrogen storage tank, the volumetric energy density (megajoules per liter) is small relative to that of gasoline. Hydrogen has a three times higher specific energy by mass compared to gasoline (143 MJ/kg versus 46.9 MJ/kg). Some research has been done into using special crystalline materials to store hydrogen at greater densities and at lower pressures. A recent study by Dutch researcher Robin Gremaud has shown that metal hydride hydrogen tanks are actually 40 to 60-percent lighter than an equivalent energy battery pack on an electric vehicle permitting greater range for H2 cars. In 2011, scientists at Los Alamos National Laboratory and University of Alabama, working with the U.S. Department of Energy, found a new single-stage method for recharging ammonia borane, a hydrogen storage compound.
Hydrogen storage is a key area for the advancement of hydrogen and fuel cell power. An article discussing the issue of storage states, “Alternatives to large storage tanks may be found in hydrides, materials that can absorb, store, and release large quantities of hydrogen gas. More work and development needs to be performed with hydrides before they are of practical use”. Some other options available for hydrogen fuel cells storage include: High pressure tanks and cryogenic tanks. Both of which strive to improve volumetric capacity, conformability, and cost of storage. The DOE’s efforts on this matter have focused on on-board vehicular hydrogen storage systems that will allow for a driving range of 300+ miles while meeting all requirements in order to stay competitive with current means of transportation.
The hydrogen infrastructure consists mainly of industrial hydrogen pipeline transport and hydrogen-equipped filling stations like those found on a hydrogen highway. Hydrogen stations which are not situated near a hydrogen pipeline can obtain supply via hydrogen tanks, compressed hydrogen tube trailers, liquid hydrogen tank trucks or dedicated onsite production.
Hydrogen use would require the alteration of industry and transport on a scale never seen before in history. For example, according to GM, 70% of the U.S. population lives near a hydrogen-generating facility but has little access to hydrogen, despite its wide availability for commercial use. The distribution of hydrogen fuel for vehicles throughout the U.S. would require new hydrogen stations that would cost, by some estimates approximately 20 billion dollars and 4.6 billion in the EU. Other estimates place the cost as high as half trillion dollars in the United States alone.
The California Hydrogen Highway is an initiative to build a series of hydrogen refueling stations along California state highways. As of 2013, 10 publicly accessible hydrogen filling stations were in operation in the U.S., eight of which were in Southern California, one in the San Francisco bay area, and one in South Carolina.
Hydrogen codes and standards, as well as codes and technical standards for hydrogen safety and the storage of hydrogen, have been identified as an institutional barrier to deploying hydrogen technologies and developing a hydrogen economy. To enable the commercialization of hydrogen in consumer products, new codes and standards must be developed and adopted by federal, state and local governments.
President Obama has shown much support for the progression of fuel cell energy. In January 2014 the Obama administration announced they want to speed up production and development of hydrogen powered vehicles. The press release states that, “by partnering with a private sector, the Obama administration thinks that it can create success stories and help speed up the process”. The Department of Energy is spreading a $7.2 million investment to the states of Georgia, Kansas, Pennsylvania, and Tennessee to support projects that fuel vehicles and support power systems. Big companies like The Center for Transportation and The Environment, Fed Ex Express, Air Products and Chemicals, and Sprint are invested in the development of these fuel cells. Fuel cells could also be used in handling equipment such as forklifts as well as telecommunications infrastructure.
Senator Byron L. Dorgan spoke out about The Energy and Water Appropriations bill earlier this year. He stated, “The Energy and Water Appropriations bill makes investments in our nation’s efforts to develop safe, homegrown energy sources that will reduce our reliance on foreign oil. And, because ongoing research and development is necessary to develop game-changing technologies, this bill also restores funding for Hydrogen energy research”. Much work has been done in developing these fuel cell cars. The U.S. Department of Energy supports next generation fuel cell systems and they are the nations lead innovative clean energy technologies. In June 2013 the DOE gave 9 million dollars in grants to speed up the technology and another 4.5 million for advanced fuel cell membranes. Minnesota based 3M will receive 3 million and the Colorado School of Mines will receive 1.5 million as well. Minnesota and Colorado are working toward these developments. Minnesota is focusing on innovative membranes with improved durability and performance. Colorado is focusing on fuel cell membranes, making them simpler and more affordable. Last year $54 million was given by the government to the SECA Program as “congress recognized and embraced the role hydrogen fuel cells and their fuels play in the portfolio of energy technologies for the 21st centuries”. The Energy and Security program was passed to boost hydrogen environmental cleanup programs and fossil fuel programs. The overall goals of these efforts are to improve efficiency and lower costs of fuel cells.
Critics claim the time frame for overcoming the technical and economic challenges to implementing wide-scale use of hydrogen cars is likely to last for at least several decades, and hydrogen vehicles may never become broadly available. They claim that the focus on the use of the hydrogen car is a dangerous detour from more readily available solutions to reducing the use of fossil fuels in vehicles. In May 2008, Wired News reported that "experts say it will be 40 years or more before hydrogen has any meaningful impact on gasoline consumption or global warming, and we can't afford to wait that long. In the meantime, fuel cells are diverting resources from more immediate solutions."
K. G. Duleep commented that "a strong case exists for continuing fuel-efficiency improvements from conventional technology at relatively low cost." Critiques of hydrogen vehicles are presented in the 2006 documentary, Who Killed the Electric Car?. According to former U.S. Department of Energy official Joseph Romm, "A hydrogen car is one of the least efficient, most expensive ways to reduce greenhouse gases." Asked when hydrogen cars will be broadly available, Romm replied: "Not in our lifetime, and very possibly never." The Los Angeles Times wrote, in February 2009, "Hydrogen fuel-cell technology won't work in cars. ... Any way you look at it, hydrogen is a lousy way to move cars."
The Wall Street Journal reported in 2008 that "Top executives from General Motors Corp. and Toyota Motor Corp. Tuesday expressed doubts about the viability of hydrogen fuel cells for mass-market production in the near term and suggested their companies are now betting that electric cars will prove to be a better way to reduce fuel consumption and cut tailpipe emissions on a large scale." The Economist magazine, in September 2008, quoted Robert Zubrin, the author of Energy Victory, as saying: "Hydrogen is 'just about the worst possible vehicle fuel'". The magazine noted the withdrawal of California from earlier goals: "In March  the California Air Resources Board, an agency of California's state government and a bellwether for state governments across America, changed its requirement for the number of zero-emission vehicles (ZEVs) to be built and sold in California between 2012 and 2014. The revised mandate allows manufacturers to comply with the rules by building more battery-electric cars instead of fuel-cell vehicles." The magazine also noted that most hydrogen is produced through steam reformation, which creates at least as much emission of carbon per mile as some of today's gasoline cars. On the other hand, if the hydrogen could be produced using renewable energy, "it would surely be easier simply to use this energy to charge the batteries of all-electric or plug-in hybrid vehicles."
The Washington Post asked in November 2009, "But why would you want to store energy in the form of hydrogen and then use that hydrogen to produce electricity for a motor, when electrical energy is already waiting to be sucked out of sockets all over America and stored in auto batteries"?. A December 2009 study at UC Davis, published in the Journal of Power Sources, found that, over their lifetimes, hydrogen vehicles will emit more carbon than gasoline vehicles. This agrees with a 2014 analysis. The Motley Fool stated in 2013 that "there are still cost-prohibitive obstacles [for hydrogen cars] relating to transportation, storage, and, most importantly, production."
Volkswagen's Rudolf Krebs said in 2013 that "no matter how excellent you make the cars themselves, the laws of physics hinder their overall efficiency. The most efficient way to convert energy to mobility is electricity." He elaborated: "Hydrogen mobility only makes sense if you use green energy", but ... you need to convert it first into hydrogen "with low efficiencies" where "you lose about 40 percent of the initial energy". You then must compress the hydrogen and store it under high pressure in tanks, which uses more energy. "And then you have to convert the hydrogen back to electricity in a fuel cell with another efficiency loss". Krebs continued: "in the end, from your original 100 percent of electric energy, you end up with 30 to 40 percent." In 2013, Volkswagen signed a $60 million to $100 million engineering services deal with Ballard for the development of fuel cells to move ahead faster with new power transportation technologies. The Business Insider commented:
Pure hydrogen can be industrially derived, but it takes energy. If that energy does not come from renewable sources, then fuel-cell cars are not as clean as they seem. ... Another challenge is the lack of infrastructure. Gas stations need to invest in the ability to refuel hydrogen tanks before FCEVs become practical, and it's unlikely many will do that while there are so few customers on the road today. ... Compounding the lack of infrastructure is the high cost of the technology. Fuel cells are "still very, very expensive".
In 2014, Joseph Romm devoted two articles to updating his critiques of hydrogen vehicles. He states that FCVs still have not overcome the following issues: high cost of the vehicles, high fueling cost, and a lack of fuel-delivery infrastructure. "It would take several miracles to overcome all of those problems simultaneously in the coming decades." Most importantly, he says, "FCVs aren't green" because of escaping methane during natural gas extraction and when hydrogen is produced, as 95% of it is, using the steam reforming process. He concludes that renewable energy cannot economically be used to make hydrogen for an FCV fleet "either now or in the future." GreenTech Media's analyst reached similar conclusions in 2014.
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Plug-in hybrid electric vehicles, or PHEVs, are hybrid vehicles that can be plugged into the electric grid and contain an electric motor and also an internal combustion engine. The PHEV concept augments standard hybrid electric vehicles with the ability to recharge their batteries from an external source, enabling increased use of the vehicle's electric motors while reducing their reliance on internal combustion engines. The infrastructure required to charge PHEVs is already in place, and transmission of power from grid to car is about 93% efficient. This, however, is not the only energy loss in transferring power from grid to wheels. AC/DC conversion must take place from the grids AC supply to the PHEV's DC. This is roughly 98% efficient. The battery then must be charged. As of 2007, the Lithium iron phosphate battery was between 80-90% efficient in charging/discharging. The battery needs to be cooled; the GM Volt's battery has 4 coolers and two radiators. As of 2009, "the total well-to-wheels efficiency with which a hydrogen fuel cell vehicle might utilize renewable electricity is roughly 20% (although that number could rise to 25% or a little higher with the kind of multiple technology breakthroughs required to enable a hydrogen economy). The well-to-wheels efficiency of charging an onboard battery and then discharging it to run an electric motor in a PHEV or EV, however, is 80% (and could be higher in the future)—four times more efficient than current hydrogen fuel cell vehicle pathways." A 2006 article in Scientific American argued that PHEVs, rather than hydrogen vehicles, would become standard in the automobile industry. A December 2009 study at UC Davis found that, over their lifetimes, PHEVs will emit less carbon than current vehicles, while hydrogen cars will emit more carbon than gasoline vehicles.
ICE-based CNG, HCNG or LNG vehicles (Natural gas vehicles or NGVs) use methane (Natural gas or Biogas) directly as a fuel source. Natural gas has a higher energy density than hydrogen gas. NGVs using biogas are nearly carbon neutral. Unlike hydrogen vehicles, CNG vehicles have been available for many years, and there is sufficient infrastructure to provide both commercial and home refueling stations. Worldwide, there were 14.8 million natural gas vehicles by the end of 2011.
A 2008 Technology Review article stated, "Electric cars—and plug-in hybrid cars—have an enormous advantage over hydrogen fuel-cell vehicles in utilizing low-carbon electricity. That is because of the inherent inefficiency of the entire hydrogen fueling process, from generating the hydrogen with that electricity to transporting this diffuse gas long distances, getting the hydrogen in the car, and then running it through a fuel cell—all for the purpose of converting the hydrogen back into electricity to drive the same exact electric motor you'll find in an electric car." Thermodynamically, each additional step in the conversion process decreases the overall efficiency of the process.
A 2013 comparison of hydrogen and battery electric vehicles agreed with the 25% figure from Ulf Bossel in 2006 and stated that the cost of an electric vehicle battery "is rapidly coming down, and the gap will widen further", while there is little "existing infrastructure to transport, store and deliver hydrogen to vehicles and would cost billions of dollars to put into place, everyone's household power sockets are "electric vehicle refueling" station and the "cost of electricity (depending on the source) is at least 75% cheaper than hydrogen." In 2013 the National Academy of Sciences and DOE stated that even under optimistic conditions by 2030 the price for the battery is not expected to go below $17,000 ($200–$250/kWh) on 300 miles of range. In 2013 Matthew Mench, from the University of Tennessee stated ""If we are sitting around waiting for a battery breakthrough that will give us four times the range than we have now, we are going to be waiting for a long time". Navigant Research, (formerly Pike research), on the other hand, forecasts that “lithium-ion costs, which are tipping the scales at about $500 per kilowatt hour now, could fall to $300 by 2015 and to $180 by 2020.” In 2013 Takeshi Uchiyamada, a designer of the Toyota Prius stated: "Because of its shortcomings – driving range, cost and recharging time – the electric vehicle is not a viable replacement for most conventional cars".
Many electric car designs offer limited driving range causing range anxiety. For example, the 2013 Nissan Leaf has a range of 75 mi (121 km), the 2014 Mercedes-Benz B-Class Electric Drive has an estimated range of 115 mi (185 km) and the Tesla Model S has a range of up to 265 mi (426 km). However, most commutes are 30–40 miles (48–64 km) miles per day round trip.
In 2013, The New York Times stated that there are only 10 publicly accessible hydrogen filling stations in the U.S., eight of which are in Southern California, and that BEVs' cost-per-mile expense in 2013 is one-third as much as hydrogen cars, when comparing electricity from the grid and hydrogen at a filling station. The Times commented: "By the time Toyota sells its first fuel-cell sedan, there will be about a half-million plug-in vehicles on the road in the United States – and tens of thousands of E.V. charging stations." In 2013 John Swanton of the California Air Resources Board, who sees them as complementary technologies, stated that EVs have the jump on fuel-cell autos, which "are like electric vehicles were 10 years ago. EVs are for real consumers, no strings attached. With EVs you have a lot of infrastructure in place. The Business Insider, in 2013 commented that if the energy to produce hydrogen "does not come from renewable sources, then fuel-cell cars are not as clean as they seem. ... Gas stations need to invest in the ability to refuel hydrogen tanks before FCEVs become practical, and it's unlikely many will do that while there are so few customers on the road today. ... Compounding the lack of infrastructure is the high cost of the technology. Fuel cells are "still very, very expensive", even compared to battery-powered EVs.
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