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A Scientific Roadmap to the Hydrogen Economy

With advances in hydrogen technology, including hydrogen-powered vehicles, we can potentially lessen our reliance on carbon-based fossil fuels.

Published November 1, 2003

By Dan Van Atta
Academy Contributor

Image courtesy of Pongsakorn via stock.adobe.com.

Picture a world economy built around the profitable production of non-polluting and endlessly renewable energy supplies – a global society freed from the shackles of dependence on oil, coal and other carbon-based fossil fuels.

Such a scenario has long been the vision, or dream to skeptics, of Dr. Amory B. Lovins, co-founder and CEO of the Rocky Mountain Institute (RMI), whose widely published views on environmental and energy-related topics have gained him global recognition for more than three decades. Lovins described his “Roadmap to the Hydrogen Economy” to a crowded meeting room of both skeptics and believers at the Environmental Science Forum held September 4, 2003 at The New York Academy of Sciences (the Academy.)

Hypercar® vehicles – ultralight, ultra-low-drag, and originally based on hybrid gasoline-electric designs – were invented at RMI in 1991 and are the most attention-getting route to energy efficiency on Lovins’s roadmap. At that time, hybrid-electric propulsion, invented by Dr. Ferdinand Porsche in 1900, was still thought to be decades away, but Honda introduced the hybrid Insight in the United States in 1999, and Toyota debuted its hybrid Prius in the U.S. in 2000. DaimlerChrysler, Ford Motor Company, and General Motors have all announced hybrid vehicles for release in the next year or two.

Eliminating the Need for Internal Combustion Engines

Dr. Amory B. Lovins

Today, Lovins told the gathering, hydrogen could be used in combination with advanced fuel-cell technology to eliminate the internal combustion engine altogether, powering a new generation of ultra-high-efficiency hypercar-class vehicles. And, he added, hydrogen-powered fuel cells that can provide economical on-site electricity to business and residential buildings can set the hydrogen economy in motion – greatly accelerating the hydrogen transition that has led Honda and Toyota already to market early (and correspondingly expensive) hydrogen-fuel-cell cars, with three more automakers set to follow suit by 2005 and another six by 2010.

“U.S. energy needs can be met from North American energy sources, including local ones,” he said, “providing greater security.” Hydrogen production just from available windy lands in the Dakotas, he said, could fuel all U.S. highway vehicles at hypercar-like levels of efficiency.

Along with a more secure domestic energy supply, moreover, Lovins said the transition from a fossil fuel-based to a hydrogen-based economy would offer a “cleaner, safer and cheaper fuel choice” that could be very profitable for both the oil and auto industries. “Hydrogen-ready vehicles can revitalize Detroit,” Lovins said.

Molecular hydrogen (H2) – a transparent, colorless, odorless and nontoxic gas – is the lightest-weight element and molecule. One kilogram of H2 packs the same energy content as a gallon of gasoline weighing almost three times as much. It’s far bulkier, too, but that may be acceptable in uses where weight matters more than bulk, such as efficient cars.

And hydrogen is in abundant supply as it may be readily derived from water, as well as from natural gas or other forms of energy.

An Energy Carrier, Not an Energy Source

Unlike crude oil or coal, however, hydrogen is not an energy source. Rather, it is an energy carrier, like electricity and gasoline, which is derived from an energy source – and then can be transported.

“Hydrogen is the most versatile energy carrier,” Lovins said. “It can be made from practically anything and used for any service. And it can be readily stored in large amounts.”

Hydrogen is almost never found in isolation, however, but must be liberated – from water by electrolysis, which requires electricity; from hydrocarbons or carbohydrates using thermos-catalytic reformers (which typically extract part of the hydrogen from water); or by other currently experimental methods.

About 8% of the natural gas produced in the U.S. is now used to make 95% of America’s industrial H2, Lovins said. Only 1% is made by electrolysis, because that’s uneconomic unless the electricity is extremely cheap. And less than 1% of hydrogen is delivered in super-cold liquid form, mainly for space rockets, because liquefaction too is very costly. But, Lovins noted, there’s already a major global H2 industry, making one-fourth as much annual volume of H2 gas as the natural-gas industry produces, and already demonstrating safe, economical production, distribution and use.

Proper Handling of a “Hazardous Material”

A highly concentrated energy carrier, hydrogen is by definition a hazardous material. But because H2 burns in “a turbulent diffusion flame – it won’t explode in free air,” Lovins said the gas consumes itself rapidly when it ignites, rising up away from people on the ground because it’s extremely buoyant and diffusive. Its clear flame, unlike hydrocarbon flames, can’t sear victims at a distance by radiated infrared.

As a result, he said, nobody aboard the Hindenburg (a hydrogen dirigible whose 1937 flammable-canopy and diesel-oil fire killed 35% of those aboard) was killed by the hydrogen fire. The modern view, he reported, is that hydrogen is either comparable to or less hazardous than common existing fuels, such as gasoline, bottled gas and natural gas.

News media interest in the potential of hydrogen-fueled electric vehicles run by emission-free fuel cells was piqued after President George W. Bush mentioned the technology in his State of the Union address this year. But Lovins noted that evaluating the technology requires an understanding of unfamiliar terms and concepts that cut across disciplines, often confusing both supporters and critics.

To explain the fuel cell, Lovins referred to the common electrolysis experiment that many students remember from their high school chemistry class. An electric current is passed through water in a test tube, splitting the water into bubbles of hydrogen and oxygen.

The proton-exchange membrane (PEM) fuel cell does the same thing in reverse: It uses a platinum-dusted plastic membrane to combine oxygen (typically supplied as air) with hydrogen to form electricity. The only by-product is pure hot water. The reaction is electrochemical, takes place at about 80 degrees Celsius, and there’s no combustion.

No Carbon Dioxide Emissions

Conventional electric generating plants make power by burning carbon-based fossil fuels (coal, oil or natural gas), or by means of costly nuclear fission, to heat water and turn large steam-turbine generators. (Hydroelectric plants use water to turn the turbines.) While fuel cells do not release carbon dioxide and other emissions, they are not yet economically competitive with fossil fuels for large, centralized electricity generation. However, Lovins said, at the point of actual use, such as the light or heat delivered in a building or the traction delivered to the wheels of an electrically propelled vehicle, mass-produced fuel cells can offer a highly competitive alternative to conventional technology.

“A fuel cell is two to three times as efficient as a gasoline engine in converting fuel energy into motion in a well-designed car” Lovins said. “Therefore, even if hydrogen costs twice as much per unit of energy, it will still cost the same or less per mile – which is typically what you care about.”

“If you buy gasoline for $1 a gallon, pre-tax, and use it in a 20-mile-a-gallon vehicle, that’s a nickel a mile,” Lovins continued. “If you reform natural gas at a rather high cost of $6 per million BTU in a miniature natural gas reformer, you get $2.50 per kilogram hydrogen, which has an energy content equivalent to $2.50 a gallon gasoline.”

That sounds expensive. But used in an ultralight and hence quintupled-efficiency hydrogen-fuel-cell powered hypercar vehicle, he added, that translates to a cost of 2.5 cents a mile. Or more conventionally, Lovins reported, in Toyota’s target for a fuel-cell car – 3.5 times more fuel efficient than a standard gasoline car – the same hydrogen would yield an operating cost of 3.3 cents per mile, still well under today’s gasoline cost.

Peak Aerodynamic Efficiency

Designed for peak aerodynamic efficiency, cutting air drag by 40% to 60% from that of today’s vehicles, hypercar vehicles would be constructed using molded carbon-fiber composites that can be stronger than steel, but more than halve the car’s weight – the key to its efficiency. Such vehicles could use any fuel and propulsion system, but would need only one-third the normal amount of drive-power, making them especially well-suited for direct-hydrogen fuel cells.

That’s because the three-times-smaller fuel cell can tolerate three-times-higher initial prices (so fuels can be adopted many years sooner), and the three-times-smaller compressed-hydrogen fuel tanks can fit conveniently, leaving lots of room for people and cargo. Replacing internal combustion engines – and related transmissions, drive-shafts, exhaust systems, etc. — with a much lighter, simpler, and more efficient fuel cell amplifies the savings in weight and cost.

Carbon-fiber composite crush structures can absorb up to five times as much crash energy per pound as steel, Lovins said, as has been validated by industry-standard simulations and crash tests. The carbon-fiber composite bodies also make possible a much stiffer (hence sportier) vehicle, Lovins said, adding: “It doesn’t fatigue, doesn’t rust, and doesn’t dent in 6-mph collisions. So I guess we’ll have to rename fender-benders ‘fender-bouncers.’”

The main obstacle to making ordinary cars out of carbon-fiber composites – now confined to racecars and million-dollar handmade street-licensed versions – has so far been their high cost. But Lovins said Hypercar, Inc.’s Fiberforge™ process is expected to offset the costlier materials with cheap manufacturing “that eliminates the body shop and optionally the paint shop – the two biggest costs in automaking. This could make possible cost-competitive mid-volume production of carbon-composite auto-bodies, unlocking the potential of hypercar designs.”

Making the Transition

Some 156 fuel-cell concept cars have been announced. In mass production, Lovins added, investment requirements, assembly effort and space, and parts counts would be “perhaps an order-of-magnitude less” than conventional manufacturing. With aggressive investment and licensing, initial production of the first hypercar vehicles could “start ramping up as soon as 2007 or 2008.”

Lovins acknowledged that transitioning to a hydrogen economy creates something of a “chicken and egg” conundrum. How can you ramp up mass production of hydrogen-fueled cars in the absence of ubiquitous fuel supplies? And who will invest in building that refueling system before the market for it exists?

Fuels cells used to provide electricity for offices and residential buildings, Lovins said, can hold the answer. “You start with either gas or electricity, whichever is cheaper (usually gas), and use it to make hydrogen initially for fuel cells in buildings, where you can reuse the ‘waste’ heat for heating and cooling and where digital loads need the ultra-reliable power. Buildings use two-thirds of the electricity in the country,” he added, “so you don’t need to capture very much of this market to sell a lot of fuel cells.” Tellingly, the fuel-cell-powered police station in Central Park kept going right through the recent New York blackout, he noted.

Leasing hydrogen-fueled cars to people who already work or live in buildings that house fuel cells would create a perfect fit, Lovins suggested. For a modest extra investment, the excess hydrogen not needed for the building’s fuel-cell generators could be channeled to parking areas and used to re-fuel the fuel-cell cars. This would permit a novel value proposition for car owners, whose second-biggest household asset sits 96% idle: Lovins said the hydrogen-powered fuel-cell cars could constitute a fleet of “power plants on wheels.”

A Need for More Durable Fuel Cells

During working hours, when demand for electricity peaks, he said the fuel cells in parked cars could be plugged in, “selling power back to the electric grid at the time and place that they’re most valuable, thus earning back most or all of the cost of owning the car: the garage owner could even pay you to park there.”

While today’s PEM fuel cells can be “better than 60 percent efficient,” Lovins acknowledged that more durable fuel cells are needed, and that mass-production is needed to bring down their cost. Eventually, he added, efficient decentralized reformers could be placed conveniently around cities and towns, mainly at filling stations.

No technological breakthroughs are needed, Lovins said, to reach the hydrogen economy at the end of his roadmap. “The hydrogen economy is within reach” – if we do the right things in the right order, so the transition becomes profitable at each step, starting now.

“[Sir Winston] Churchill once said you can always rely on the Americans to do the right thing,” Lovins concluded, “once they’ve exhausted all the alternatives.” We’re certainly, he wryly added, “working our way well down the list. But, as Churchill also said, ‘Sometimes one must do what is necessary.’”

Dr. Klaus S. Lackner

Adding fuel to the discussion, Dr. Klaus S. Lackner, the Ewing Worzel Professor of Physics in the Department of Earth and Environmental Engineering, The Earth Institute at Columbia University, briefly responded with some thoughts on Lovins’s proposals.

Other Points of View

After agreeing that “things will have to change, business as usual will not work,” due mainly to the need to curb carbon dioxide emissions, Lackner raised a number of issues he believes proponents of the hydrogen economy should consider.

For example, Lackner said off-peak power costs should not be used to calculate the cost of producing hydrogen fuel from electricity, as the hydrogen-generation industry will “destroy” the structure of off-peak pricing. “There may be a benefit to the electricity market in that power generation profiles become flatter, but this will be a benefit to people running air conditioners at 4 p.m., not to the hydrogen economy.”

“Hydrogen will be made from fossil fuels,” Lackner stated, “because it is much cheaper than by any other route.” He also noted that fuel cells and hydrogen are not synonymous. “Hydrogen can work without fuel cells, and fuel cells can work without hydrogen.” Although Lovins’s vision emphasizes PEM fuel cells, Lackner added that “some fuel cells run on methane. You can use any hydrocarbon you like; we can debate which is the best fuel.”

Many Competing Options

It’s also important to remember that hydrogen is an energy carrier, like electricity, not an energy source. “One needs to compare the advantages of hydrogen as an energy carrier with those of other energy carriers,” Lackner said.

Regarding Lovins’s designs for ultralight hypercar vehicles, Lackner said there  are many competing options for changing the internal combustion engine. “It’s not fair to compare old fashioned conventional cars, on the one side, with the new, fancy cars on the other side. We need to compare each of the potential energy carriers side by side, and not assume that the competition stands still.”

Lovins largely agreed with these comments, but felt that they didn’t affect the validity of his recommendations.

Also read: Better Batteries for Electric Cars


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