Everyone from automakers to environmentalists to politicians is touting hydrogen fuel cell cars as the wave of the future. But just how soon will that wave arrive? Most experts agree that major technological and economic hurdles need to be cleared before these silent, pollution-free automobiles proliferate on the nation's highways.
The question is, is the likelihood of overcoming these challenges sufficiently realistic to warrant near-term investment, as Dan Sperling argues? Or, as Joe Romm believes, will it take many decades for those challenges to be met and therefore should we focus much more now on alternatives such as fuel efficiency (hybrids) and biofuels? The answer has implications for how—and how urgently—we address worsening problems growing out of our present "gasoline economy," including oil dependence, air pollution, and, as most scientists now agree, global warming.
Beginning on July 26, these two experts on hydrogen fuel cell cars began squaring off on this page. Over the course of a week, they will comment on the status and prospects for solving "the four most fundamental technological and economic challenges" to hydrogen-fueled transportation, as noted in the 2004 National Academy of Sciences' report "The Hydrogen Economy: Opportunities, Costs, Barriers, and R&D Needs."
If you want more background on this debate, see the four challenges as spelled out in detail in the 2004 report. Then, during or after the debate, feel free to post your own comments on the PBS Discussion Board.
Moving Forward With Near- and Long-Term Strategies
Energy trends are clearly headed in the wrong direction, with oil becoming more expensive, demand soaring, and companies and countries scrambling to lock up remaining supplies. Moreover, evidence continues to mount that emissions from fossil fuel combustion are altering the climate, melting glaciers, and raising temperatures.
It's only going to get worse as the rest of the world seeks the same high-energy lifestyle we enjoy in the U.S. Yet we do little. Humans are behaving like the proverbial frog in a pot of slowly heating water, oblivious to the fact that it will soon be cooked.
Joe Romm and others argue that the most sensible response is to improve energy efficiency. I fully agree. Large fuel improvements are possible with incremental improvements to today's vehicles. Even greater improvements are possible with diesel and hybrid electric technology. Bringing about these efficiency changes will require strong policies. Historically, regulators resisted diesel engines because they produce more air pollution, and consumers have opted for ever more power and mobility. And even with higher efficiency vehicles, the burgeoning vehicle population worldwide means a net increase in emissions and oil use.
That is why we are debating hydrogen.
Sometime soon global oil production will peak, and we will need to complement the near-term efficiency strategy with a non-oil, non-carbon energy system for transport. There are three basic strategies for doing so: converting wastes, wood, and grasses to liquid and gaseous fuels; running vehicles on electricity; and replacing oil with hydrogen. All are promising, and all deserve more attention. But hydrogen, together with fuel cells, has the greatest potential to dramatically reduce pollution, greenhouse gases, and oil use. Hydrogen and fuel cell vehicles will only come about with a concerted effort over a long time. Not to make that concerted effort is irresponsible and foolish.
Hydrogen Without the Hype
Hydrogen fuel cell cars increasingly appear to be an environmental dead end. At the same time, the scientific consensus is strengthening that human-induced global warming may well be catastrophic. That's why Tony Blair committed Britain to "reduce our carbon dioxide emissions by 60 percent by 2050."
We must start cutting emissions quickly. Yet even hydrogen advocate Dan Sperling wrote in 2004: "Hydrogen is neither the easiest nor the cheapest way to gain large near- and medium-term air pollution, greenhouse gas, or oil reduction benefits." So, hydrogen is a misdirection of resources away from strategies that can achieve far larger benefits for far less money for decades to come.
When will hydrogen cars make sense? Bill Reinert, U.S. manager of Toyota's advanced technologies group, was asked in January 2005 when fuel cell cars would replace gasoline-powered cars or hybrids, and he replied, "If I told you never, would you be upset?" The Director of MIT's Sloan Automotive Lab told Congress this month, "the total time to noticeable impact" for hydrogen fuel cell cars "is likely to be more than 50 years."
As a 2003 analysis in Science magazine concluded, hydrogen won't be close to a cost-effective climate solution "until CO2 emissions from electricity generation are virtually eliminated." We just can't wait that many decades. Worse, a 2004 report from the European Union's Joint Research Centre found that hydrogen cars deployed anytime soon could well increase greenhouse gas emissions.
So we are several decades from a time at which serious investments in hydrogen cars or infrastructure makes sense environmentally. While we wait, we must push fuel efficiency and advanced hybrids. We should promote biofuels and hybrids that can be plugged into the electric grid, as discussed in my book The Hype about Hydrogen.
Industry Is Leading the Way
Private industry is leading the development of cost-effective, durable, safe, and environmentally desirable fuel cell vehicles. General Motors, Toyota, Honda, DaimlerChrysler, Nissan, and Hyundai are most aggressive, each devoting at least $100 million per year in R&D to fuel cell vehicles, and some much more. A variety of technology and energy companies are also investing considerable sums.
In the public sector, the U.S. Department of Energy is spending about $100 million per year on fuel cell vehicles and hydrogen storage—far less than what the private sector is spending collectively.
This is the first time automakers have willingly devoted so much effort to an alternative to gasoline and diesel. Their investment is driven by their belief that fuel cell vehicles will be cost competitive and attractive to customers. Toyota says it will reduce costs to $50,000 per vehicle by 2015. General Motors is even more optimistic.
Certainly, challenges remain. While today's fuel cell vehicles perform superbly, they are expensive hand-built prototypes. Much effort is needed to further reduce costs, improve durability, ensure safety, extend driving range, and develop efficient manufacturing processes. Not all of this effort can, or should, be expended by individual companies. Overall safety relies not only on vehicle design, but also on codes and standards. Driving range is partly a function of refueling infrastructure. Public spending is needed to solve basic scientific questions, assure public safety, and reduce risk during initial commercialization.
How quickly all this will be achieved is uncertain. Most of the money being invested is not government money. Given the potentially large public benefits, the large industry investments, and the belief of many automakers that they can build competitive zero-emitting fuel cell vehicles, we as a society would be foolish and irresponsible if we did not encourage those investments.
Decades Away From a Hydrogen Car
We are two major scientific breakthroughs away from addressing these challenges. Absent these breakthroughs, hydrogen cars will remain unaffordable and impractical.
Current fuel cell vehicles cost $1 million more than regular cars, largely because the proton-exchange membrane (PEM) fuel cells they use are so expensive. To make affordable cars, PEMs will have to cost under $50 per kilowatt (an internal combustion engine costs about $30/kW). Current PEM costs are 40 to 100 times greater.
Historically, the fastest that any clean energy technology has dropped in price is a factor of 10 over two decades, which both wind and solar power did with much government support. While it is theoretically possible PEM price drops could outpace every other energy technology of the past half century, it is rather unlikely and requires a breakthrough.
Interestingly, the best fuel cell vehicle, from Honda, is no more efficient than the best hybrid, the Toyota Prius. I suspect that will always be the case.
The hydrogen storage challenge is even more problematic than the PEM challenge because hydrogen is such a diffuse gas. Virtually all hydrogen cars today use ultra-high-pressure storage, an expensive and inefficient strategy that still gives them only half the range of regular cars. The prestigious National Academy of Sciences panel concluded last year that the government "should halt efforts on high-pressure tanks and cryogenic liquid storage.... They have little promise of long-term practicality for light-duty vehicles."
A March 2004 study by the American Physical Society concluded that "a new material must be discovered" to solve the storage problem. That could happen tomorrow. And given that we've already examined some 2,000 potential storage media, it might never happen at all.
So let's keep doing the basic research, but realize we are probably decades away from having a practical fuel cell car.
The Toughest Challenge
The chicken and egg problem—who will buy hydrogen cars if a fueling infrastructure is not in place and who will build the fueling infrastructure before the cars are a marketplace success—remains the most intractable challenge. No other alternative fuel has ever solved this problem, and hydrogen is by far the most difficult and expensive alternative fuel to make, transport, and pump into a car.
A 2002 analysis by Argonne National Laboratory found that "the hydrogen delivery infrastructure to serve 40 percent of the light-duty fleet is likely to cost over $500 billion." In 2003, Royal Dutch/Shell put the price to supply "in the U.S. alone just 2 percent of cars with hydrogen by 2020" at "around $20 billion." Analyses that suggest the cost could be considerably less do not seem to be based on any genuine cost modeling and require major breakthroughs in both hydrogen production and delivery.
If the chicken and egg problem is to be solved, government will have to heavily subsidize the fuel providers. But for the foreseeable future, the only affordable hydrogen infrastructure is fossil-fuel based, either reforming natural gas or grid electrolysis. As the 2004 National Academy of Sciences panel wrote, "fossil fuels will be the principal sources of hydrogen for several decades."
It makes no sense whatsoever for the government to subsidize hydrogen from fossil fuels. The best fuel cell car today running on hydrogen from natural gas or grid electrolysis has higher greenhouse gas emissions than the Toyota Prius running on gasoline. Why should the government squander billions subsidizing infrastructure that doesn't even help our biggest environmental problem?
Deploying hydrogen infrastructure that is fossil-fuel based—indeed, deploying infrastructure before we've had the technology breakthroughs in fuel cells and hydrogen storage that are required for practical cars—is wildly premature.
Hydrogen Can be Profitable and Reduce Emissions—Even with Natural Gas
All new infrastructure costs money, including expanding and maintaining the existing gasoline infrastructure. Romm obscures the discussion and makes incorrect assertions. The real question is: Can hydrogen be produced profitably and with real emission benefits?
Most objective studies, including those by the National Academies, DOE, and UC Davis, suggest that the answer to this question is yes. Hydrogen can be produced, distributed, and dispensed at large scale at a cost of $3-5 per gasoline-equivalent gallon with technology that exists today (no breakthroughs needed), and even less with continued R&D. Since fuel cell vehicles are more than twice as energy efficient as gasoline combustion engines, the cost of hydrogen to the consumer should be similar to gasoline on a cents/mile basis.
Hydrogen faces real challenges during the early phase of the transition, but it is not necessary to build a nationwide infrastructure "all at once" and costs can be controlled through a strategic roll-out that matches deployment infrastructure with deployment of vehicles.
Romm also states that fuel cells running on hydrogen from natural gas have higher greenhouse gases than the Toyota Prius. This is simply not true. Studies from MIT, Argonne, UC Davis, and others show a 10-40 percent reduction. Moreover, it is relatively easy to remove carbon from natural gas (and coal) when they are converted into hydrogen—something not possible with gasoline-powered hybrids. And by investing heavily in renewable power for electricity production today, we can lay the foundation for a renewable hydrogen future with near-zero greenhouse gases.
Due to the long time scales involved in a transition toward any new fuel, including hydrogen, we should not await the perfect solution before beginning the transition. Infrastructure solutions exist to start us on the path toward domestically produced, near-zero-carbon hydrogen fuel.
Toward Renewable Hydrogen Energy
Eventually, vehicles must be fueled by either renewable energy or non-petroleum fossil energy with carbon sequestration. The fossil industries have a large incentive to solve the carbon problem and are already seeking to do so. They may or may not succeed.
With renewable energy, there are three possible paths: conversion into a liquid or gaseous fuel for use in combustion engines; into electricity for use in a vehicle powered by a battery (or "third rail"); or into hydrogen for use in fuel cells. All have shortcomings. Combustion engines are inherently inefficient; batteries are improving but remain heavy, bulky, and expensive; and renewable hydrogen is currently expensive because of minimal investments to date in technologies needed to make hydrogen from wind, water, solar radiation, or biomass. Where substantial effort has been applied, for instance with wind power, renewable energy costs have dropped sharply.
The best near-term use of renewables to cut greenhouse gas emissions is replacing coal-based electricity (at least in the U.S.). However, as use of renewables increases, substantial additional reductions can be made by replacing fossil fuels with renewable hydrogen.
Ongoing advances in electric technologies are already enhancing mid-term prospects for renewable hydrogen. As fuel cell costs drop, essentially identical electrolyzer costs will also drop, reducing costs for water splitting. And as coal gasification costs drop, so will biomass gasification costs. Longer term, the 2004 National Academies study identified many promising renewable processes for making hydrogen. With even modest R&D investments in these new processes, dramatic progress is likely.
The eventual success of disparate renewable energy processes is impossible to predict. But when society focuses its resources and brainpower on new challenges, whether landing on the moon or electrifying America, it succeeds. It is a challenge to produce renewable hydrogen cheaply, but if we concentrate our efforts, we will likely succeed.
Away from Renewable Hydrogen
"Electrolysis of water with 'renewable electricity' from solar or wind energy does not appear a plausible way to produce hydrogen; it makes much more sense to use renewable electricity to displace coal in the electric power generating sector," the Director of MIT's Sloan Automotive Lab told Congress in July.
This is a key point. Probably the biggest analytical mistake made in most hydrogen studies—including the 2004 National Academy report—is failing to consider whether the fuels that might be used to make hydrogen could be better used simply to make electricity.
A megawatt-hour of electricity from renewables like wind power, if used to make hydrogen for a future fuel cell vehicle, would save under 500 pounds of carbon dioxide compared to the best current hybrids. That is less than the savings from using the same amount of renewable electricity to displace a future natural gas plant (800 pounds), and far less than the savings from displacing coal power (2,200 pounds). And you don't need to build the expensive electrolyzer, hydrogen delivery infrastructure, and fuel cell vehicle.
So, until the electric grid is virtually CO2-free, making substantial amounts of renewable hydrogen will hurt efforts to reduce greenhouse gas emissions. Yet the U.S. Congress won't even pass a law requiring 10 percent renewables by 2020. Barring a drastic change in U.S. energy policy, our electric grid will not be close to CO2-free until well past 2040.
And any future excess zero-carbon electricity would be better used to charge the battery on a hybrid that can be plugged into the electric grid. Such a "plug in" hybrid or e-hybrid can travel three to four times as far on a kilowatt-hour of renewables as a fuel cell car, since it avoids the huge inefficiency of converting electricity to hydrogen and then back to electricity.
Sequestration: Promising for Electricity, not for Transportation
Costs for carbon sequestration are currently quite high, $100 to $300 a ton, according to the Department of Energy's Office of Fossil Energy. A 2003 National Academy of Sciences workshop concluded, "At the present time, technology exists for the separation of carbon dioxide and hydrogen, but the capital and operating costs are very high, particularly when existing technology is considered for fossil fuel combustion or gasification streams."
Recent attention has focused on pumping highly compressed liquid CO2 into geological formations, such as deep underground aquifers. Yet liquid CO2 is less dense than water and prone to leak.
Even tiny leakage rates can undermine the value of sequestration. If we are trying to stabilize CO2 concentrations at twice preindustrial levels, a 1 percent leakage rate could add $850 billion per year to overall costs by 2095, according to one study. If we cannot be certain that leakage rates are below 1 percent, the study concluded, it will be difficult "to convince regulators that CO2 injected into geological formations should be accorded the same accounting as CO2 that is avoided" (through technologies such as wind power). The authors note, "there is no solid experimental evidence or theoretical framework" for determining likely leakage rates from different geological formations.
How long will it take before carbon capture and storage (CCS) emerges as a major solution to global warming? That remains uncertain. As Princeton's Bob Williams wrote in 2003, "One cannot yet say with high confidence that the CO2 storage option is viable."
While CCS is an important option to pursue for reducing carbon emissions from electricity generation, making hydrogen for cars from coal (even with CCS) is counterproductive from a greenhouse gas mitigation perspective, until the electric grid is virtually CO2-free. Coal remains an unlikely source of transportation-related hydrogen for many decades.
Carbon Sequestration Could Play a Critical Role
Fossil energy supplies 85 percent of world energy use and is projected to expand into the foreseeable future, especially coal. As a result, carbon capture and storage (CCS) will need to be an important tool for decarbonizing electricity production and transportation if we want to stabilize atmospheric CO2 concentration at reasonable levels.
It is not feasible to capture carbon from hundreds of millions of vehicles, but it is straightforward to do so at a coal plant producing electricity and/or hydrogen. Hydrogen can be made by gasifying coal and capturing and sequestering the carbon. The gasified coal can also be used to produce electricity in a turbine. All the technologies are known, including those for CCS. Dismissing CCS would leave few options for addressing greenhouse gas emissions from all sectors.
Even at $30/ton of CO2, electricity rates for the consumer would be about 25 percent higher (from $0.10 to 0.125/kWh), and hydrogen from coal would cost about the same as gasoline today. This seems to be a small price to pay for addressing climate change.
Romm rightfully points out the uncertainty about leakage and the need for more research in this area. But much is known already, from the oil industry's decades of experience injecting CO2 underground to extract oil, and from a large number of ongoing international studies. We also know that there are many naturally occurring deposits of CO2 and natural gas, suggesting that CO2 can be contained for geological time scales.
Many other questions remain unanswered. Is there enough carbon storage capacity to make a difference to the climate? Does this strategy "lock-in" fossil energy, delaying renewables? Will the public accept sequestration?
In the end, CCS is a powerful tool to enable low-carbon, low-cost fossil hydrogen. It could buy us time until low cost renewables flourish.
The Car of the Future
Hydrogen is the most challenging of all alternative fuels. As the National Academy of Sciences recently noted, "using hydrogen as a transportation fuel would necessitate several significant breakthroughs." And hydrogen offers little prospect of helping to reduce greenhouse gas emissions for four or more decades.
So what will we be driving in the future to reduce greenhouse gas emissions and oil consumption?
In the near-term, by far the most cost-effective strategy for reducing emissions and fuel use is efficiency. Hybrid gasoline-electric vehicles can reduce gasoline consumption and greenhouse gas emissions 30 to 50 percent with no change in vehicle class and hence no loss of jobs or compromise on safety or performance.
Absent tough fuel-economy regulations, however, hybrid technology will increasingly be used to boost horsepower. So the current energy bill, which provides subsidies for hybrids but no fuel economy or carbon dioxide regulations, represents a major failure of political leadership.
Ultimately, we will need to replace gasoline with a zero-carbon fuel. The most promising pathway is a hybrid that can be connected to the electric grid (discussed at length in the new paperback edition of The Hype About Hydrogen).
These so-called plug-in hybrids or e-hybrids will likely travel three to four times as far on a kilowatt-hour of renewable electricity as fuel cell vehicles. Ideally these advanced hybrids would also be a flexible-fuel vehicle capable of running on a blend of biofuels and gasoline. Such a car could travel 500 miles on one gallon of gasoline (and five gallons of cellulosic ethanol) and have under one-tenth the greenhouse gas emissions of current hybrids.
Long-term research into hydrogen cars makes sense. But for the sake of the global climate, most of the near-term development and deployment money now being spent on hydrogen should be shifted over to plug-in hybrids and biofuels.
The Time for Hydrogen and Fuel Cell R&D Is Now
Skepticism about hydrogen is healthy. Toyota anticipated only a 5 percent chance of success in 1995 when it launched its hybrid Prius project. Perseverance obviously paid off. Fuel cells and hydrogen pose even greater challenges but promise even greater benefits.
We need to pursue short- and long-term strategies. Energy efficiency should be the first priority, but it can't give the long-term deep cuts needed to stabilize the climate, clean up our urban centers, or eliminate oil imports. Hydrogen is one of a few options that can. Biofuels and electric vehicles are the other two worth considering. All three are likely to succeed to some extent. All should be pursued.
Unfortunately, this country fails to acknowledge the seriousness of climate and energy security problems and the long time scales required to change the energy system. Despite recognition by leaders in industry, academia, and government, we are failing to adopt the necessary policies that encourage efficiency innovation and send strong signals to industry and consumers that petroleum and climate change are grave concerns. Investing in the future is obviously not on the agenda.
Equally disturbing, the country is spending far less on energy R&D than it did 20 years ago. Clean energy R&D is woefully underfunded by both industry and government. If we do not aggressively pursue R&D on hydrogen, fuel cells, and other clean energy, including some strategically planned demonstrations, hydrogen will not be ready in 20 years. Failure to pursue hydrogen and other fuels that promise massive reductions in oil use, pollution, and carbon emissions is irresponsible.
Photos: (Daniel Sperling) Courtesy Dr. Daniel Sperling; (Joseph Romm) Courtesy Dr. Joseph Romm
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