Commentary Index
The Promise of Hydrogen (*Written in 2000) [Commentary 1.1] Dr. Robert J. Wilder President, The Hydrogen Fuel Cell Institute * Note: While the following is dated, it was written back in Spring 2000 and so has been overtaken by more recent news, this may be of background interest There's much divergence, in the ways that one could envision the future for hydrogen (H2). Seen most optimistically, H2 could be seen as a remarkable energy carrier - a bold dream too long overlooked, with the potential to some day transform energy systems. Holding out the promise of clean, abundant, and firm power, using renewably-made 'green' hydrogen to power fuel cells, or engines, might potentially help in the future to reduce reliance on oil, and prevent greenhouse gas emissions. On the other hand, consider that use of hydrogen as an energy carrier, is almost non-existent today. Look at the steep costs and the difficulties of using H2 for energy needs, or think of hydrogen's lack of power density as a gas, see prohibitive costs anyway of fuel cells today, and the fact that renewable sources like wind or solar are still sparse for making H2, and it is easy to conclude that visions of hydrogen as energy carrier are an idealist's dream unlikely to be realized. One may reasonably thus say, that without core technological breakthroughs, the 'Hydrogen Economy' ideal is merely a mirage. There's arguably a third view, however, between these two extremes above. It starts out by accepting that Yes, many vexing technical problems would have to be overcome in decades ahead for both H2 and FCs. These are immense - perhaps insurmountable. Nonetheless these engineering efforts - even if not successful, arguably are worth the effort, and may yet bear fruit. One shouldn't dismiss inventive genius of humankind, in advancing H2 FCs. This latter, more hopeful view has precipitated the following text, on the theoretical and yet elegant advantages that H2 FC systems might one day bring. At the outset, and unlike unproven technologies, note that a leap of faith isn't needed to see H2 & FCs 'working' in the first place as energy conversion systems. Even critics of the 'Hydrogen Economy' concept, acknowledge that H2 fuel cells 'work', and in ways fairly-well understood. In fact, a working small H2 FC unit sits next to me now. (Their vast cost is the core problem, as will be discussed below). It's because they work, in ways intriguingly different from fossil-fuels + engines, that their future is so captivating. H2 & FCs are often thought-of as most useful, when put together. Producing hydrogen requires first, releasing this most-common element from, for instance, water. The function of hydrogen is thus to store desired power as an energy carrier; the fuel cell then converts H2 into electric power wherever it's needed - and will do so, as long as H2 is supplied to the FC. Put aside for a moment the exorbitant costs today of H2 FC systems, and the fact that H2 itself requires energy in order to be produced (and it should therefore be made from 'green' renewable sources like wind or solar). As a way to store and use power - hydrogen, in combination with fuel cells are little short of revolutionary. And yet, fuel cells are hardly new. Invented in 1839, they were long seen mainly as a novelty, for working electrochemically, rather than by combustion. Ever since, FCs have found only sporadic uses, mainly in cases where their very high cost is not an object, including spacecraft - or where high-quality firm power is a necessity - or because they can make portable power far longer than conventional batteries. What helped drive past bouts of investor interest, is a view (in a leap of faith) that FCs can be made at costs so attractive, they're potentially competitive with oil, batteries, etc. Can great price reductions be found, so that FCs are one day just a tenth the cost of current hand-built prototypes? Or, has the allure of disruptive technology led to irrationally exuberant valuations? The answer to this question shall in time, prove key. In the meantime, we can sketch out here what H2 FCs could together, in theory, bring. First, early FCs that may be brought to market, are likely to run on more convenient fuels than hydrogen. Candidates include new liquid proprietary fuels, perhaps involving methanol, or butane, or for large systems gaseous fuels, like propane or natural gas. Small FCs for personal electronics, including cell phones might use liquids that contain an electrolyte. Larger FCs in stationary settings, could provide say, the back-up power for hospitals or computer centers now utilizing natural gas lines. To give some hard data for costs, one FC manufacturer has claimed a megawatt class field test came out to $8,000 per kilowatt in the late 1990s - a real reduction from the $20,000 per kilowatt in prior trials, but pricey at 17 cents per kilowatt/hour (kWh). While they may hope to eventually reach installed costs of just $1,200 per kilowatt, for costs of roughly 5 cents per kWh(!), that's a strikingly lofty goal which is still far away. That would compare favorably to prices around the U.S. a few years back, ranging around 1998 from 10+cents, to the cheapest at about 4 cents per kWh (prices are somewhat higher today). This paper will consider the potential that H2 FCs, might together, one-day hold. We'll have to imagine, though, that breakthroughs occur to allow sky-high FC costs to be resolved, along with advances in using H2. Ways this all might someday be achieved, are impossible to say today: perhaps by combination of proprietary hydrogen-rich liquid fuels, inexpensive electrolytes in FCs, nanotubes, nanotechnology, photobiological H2 production, or unimaginable advances, but we'll start with that hypothesis. Possibilities? There's many conceivable paths ahead for FCs. Think of cases where batteries can't meet mounting demands of personal electronics, or where continuous FC power would be advantageous… imagine then, as first-mover fuel cells are adopted early-on, and penetrate further markets in military, and other specialized applications - and later grow more practical, after the technical 'glitches' are ironed out… next, imagine state of the art twenty years later -- after billions more research dollars, more improvements, and the economies of scale, that going from R&D to commercial manufacturing can bring. That end-point helps explain past exuberant enthusiasm here. Put aside for a moment, the environmental advantages of green H2 and fuel cells - which can be major - and still their potential operational characteristics merit thought. A 'common' fuel cell can utilize hydrogen, plus the oxygen that's easily taken from air, to make desired electricity; there also is some water and heat produced, but nothing else. This is elegantly simple. In a typical cell, a catalyst splits the hydrogen into two constituent parts: protons (hydrogen ions) and electrons: the protons pass through a membrane to the other side and combine with oxygen making water. But this membrane forces electrons into an external circuit to the other side: that's electric power. Five main types currently lend themselves to many applications - this commentary is being written in 2000, and so advances are certain in years and decades ahead. The present five are distinguished by their electrolyte, which also determines the operating temperatures of the fuel cell (often hotter ones are more efficient, and fuel-flexible, but hotter temperatures also introduce thorny issues). They're the proton exchange membrane (PEM, or polymer electrolyte) which operates at about 80 degrees C, alkaline fuel cell (AFC) at about 100 degrees C, phosphoric acid (PAFC) at about 200 degrees C, molten carbonate (MCFC), and solid oxide fuel cell (SOFC) both at 800 degrees C. Other types may be refined, like direct methanol FCs (although methanol itself is toxic), and regenerative FCs, if interest grows. Think of possible benefits that might come from beginning to substitute fuel cell power, in place of centralized utility power plants. Note that buildings account for ~two-thirds of U.S. electricity consumption. To conceivably move towards "distributed generation" (DG) should make it possible to better current efficiencies, and by quite a lot. Also, the high-quality waste heat byproduct is good for key building tasks of heating and cooling. Compared to modern coal-fired power plants, where much energy (including heat) is still wasted at the source, and fails to reach customers, these fuel cells if ever economical should start with an advantage. Fuel cells might in theory compound efficiencies, for they are scalable from micro through massive stationary applications, and especially suitable to decentralized power. This idea of localized, distributed power means as noted, that electricity is generated by appropriately-sized sources located near to need. Place an early round of stationary fuel cells where it's easiest to initially compete on more favorable economic terms - if an existing grid is loaded, expansion is expensive, or rural areas where there's no power grid, or high-quality power is a necessity - and their very high cost could be a bit less of an issue. That said, there's no doubt but that FCs are today (in 2000) wildly expensive. Generating power closer to where it's needed may help eliminate huge costs associated with putting in miles of expensive wires on the grid. (That constraint has been an issue, for example for wind power; hence making H2 nearby wind farms and transporting it via H2, might make some sense). It also helps address transmission losses and costs of power delivery, which in 1996 averaged 2.4 cents per kilowatt-hour. And it's flexible; a molten carbonate FC unit can use varied hydrocarbon fuels like natural gas, methanol, diesel, even coal gas - although we believe using 'green hydrogen' is ecologically best. So why aren't fuel cells now powering our homes, offices, cell phones or cars around the world? Because as emphasized, their costs are still wildly high today, no matter what the fuel that's used … and of course there's no infrastructure yet to transmit hydrogen, if that's the energy carrier. Each FC is hand-built, by highly-trained Ph.Ds and many require gobs of pricey catalysts like platinum. While a well-proven technology, H2 FCs cannot come near the unbeatable price of King Oil burned in engines of all types. (We believe that FCs may become cost-effective in certain applications later this decade, and that will be an interesting development, but many problems must be overcome). Real cost reductions in some FCs could occur this decade, should flowering research lead to unprecedented mass manufacturing. Mass production that's enabled by unexpected engineering refinements, might work down costs, as economies of scale are realized. Look farther ahead, and imagine fuel cells run by green hydrogen - one of the toughest challenges and something that requires means of making and moving cheap, renewable hydrogen in the first place: it is a distant but invigorating prospect. In powering portable electronics (cell phones, laptops), new FCs might appear sooner rather than later. Yet for other notable cases, FCs would probably not appear for many decades, such as in vehicle propulsion. In 1998, these prototype FC "engines" such as for cars (where FCs face the stiffest competition) were dear, costing around $3,000 per kilowatt. (Even at $100/kW their costs must be brought down further, compared to the rival ICE engine today). The 'eye-opening' $3,000/KW price may be brought down quite far, if one looks at the technical possibilities; estimates by Amory & Hunter Lovins, and Paul Hawken in their book 'Natural Capitalism', saw costs for auto FC engines dropping to perhaps $500-$800 per kilowatt, perhaps less, if designs improve and production numbers vastly grow. And, FCs could sooner be range extenders in mainly electric cars. To depart from the conventional wisdom, sometimes can be well rewarded. Think of the hybrid gasoline-electric car, like the Toyota Prius: before that car was introduced, many analysts had claimed (wrongly) the hybrid idea wouldn't work - let alone, ever be more efficient than gasoline-only vehicles. And yet, look at these hybrids that have in just a few years. grabbed market-share for being considerably efficient in their own right. FCs in car propulsion is a daunting idea, but it garners a lot of imaginative attention. For FC propulsion, meeting required hours of operation without degradation, the challenge of cold starts, and solving the conundrum of fuel storage are tremendous barriers in cars. Yet serious work by Honda, Toyota, DaimlerChrysler, and others on vehicle prototypes - makes clear this FC race is afoot. To augment movement towards a 'hydrogen economy', consider too that fuel cell-powered cars may one day have 50 kW generating capacity. Because cars are habitually parked at home, or work, they could thus become mobile power plants where you might plug in your car - not to charge its battery - but to help power your home or office! And net metering will mean you can sell excess power to the grid. To add insult to injury, FC vehicles may accelerate faster, go farther, last longer with fewer moving parts, and be safer, than present cars. While automotive powertrains are probably going to be one of the most difficult arenas for fuel cells to compete, given the presently very low costs of the rival highly-refined Internal Combustion Engine (ICE), some future may be in fuel cells as Auxiliary Power Units (APUs) powering robust 42 volt car electrical systems. And APUs may one-day make on-board power for big rig tractor-trailers, or to extend range in EVs. Again this is all contingent upon vast strides being made in reducing FC costs; but the concept is valid. If so, then over decades it might be possible to greatly reduce the parts in FCs, and size / cost of 'balance of plant' supporting the fuel cell stack itself. And, it's conceivable some fuel cells might become solid state; like the revolution from tubes to transistors, this could improve reliability and add engineering elegance. With an advent of beautifully elegant H2 FC systems, oil as a source of power to do work, could in theory (like steam or horse power of a century ago) be made largely a thing of the past. Vexing ecological issues too such as global climate change and greenhouse gases, or loss of marine biodiversity, may be addressed by H2 fuel cells. The key to note here, is that: prevention is better than cure. For instance, avoiding use of oil in the first place helps prevent greenhouse gases, and pollution, transport of oil at sea with its discharges; it avoids contaminants exiting auto tailpipes that precipitate downwards to the sea, or that pollute the air. The goal then, should be to generate H2 cleanly and sensibly. Nearer-term, to use new proprietary liquid fuels in small FCs, or to reform natural gas, etc, could make good sense, as early fuel options for FCs. Yet on the longer view, it's clearly best to build 'green' hydrogen infrastructure based upon renewable energy sources, for producing hydrogen, should FCs grow more feasible in their own right (or for ICEs running on H2 which is certainly feasible). This means making hydrogen smartly, from low and zero-carbon sources like wind, solar power, photobiological means, etc. Given sparse industrial demand for hydrogen, used such as cooling large motors -- compared to what could be, for H2 as an energy carrier, little attention has been paid to finding ways to make this 'fuel' from, for instance, water. Today about 95% of hydrogen comes from reforming natural gas. However, should we begin adopting fuel cells, then past inattention might change. New means for storing and moving the hydrogen, safely and cheaply might one day be found, including by carbon nanotubes. Distant possibilities, include arrays of inexpensive solar power, or large wind power farms that together produce terawatts, closing energy flows, softer energy paths, and growing efficiency. Other novel ideas may be just over the horizon. They include using algae to make hydrogen photo-biologically, carbon nanotubes to store it safely and efficiently for use anywhere, or massive ramping-up of renewable energy overall, with hydrogen from the surplus used for firm power. Whatever the means, sensibilities demand that we keep our eye on the prize: it's green hydrogen that renders fuel cells an amazing energy option, and in the long run, no other energy carrier will do. We welcome comments on the above Commentary 1.1. Dr. Rob Wilder To contact us, see our "Contact Us" page, or email the author at rob@h2fuelcells.org. |