(Updated July 2004)
Electrical and Communication Systems Division
National Science Foundation*, Room 675
Arlington, VA 22230
Back at the time of the great oil shocks of 1973 and 1979, many of us in all sectors of the society asked hard questions about the long-term prospects and sustainability of the world’s energy systems.
We asked: “Can we really survive all this, in the long-term, and if so, how?” Despite the wide diversity of views, certain core realities did emerge from the intense discussions and research of the early 1980’s. Back in those days, I was the lead analyst at the Energy Information Administration (EIA) of the U.S. Department of Energy (DOE) assigned to evaluate the various long-term models and analyses, the technical and economic assumptions going into them, the common theories, and what we could really learn from them all. (For example, see the sources cited in my chapter “Energy and Population” in Lindsey Grant, ed, Elephants in the Volkswagen, W.H. Freeman, 1992. See also the special issue on Engineering-Economic Modeling in Energy: The International Journal, March/April, 1990.)
There was, and remains, a bewildering complexity of numbers, technologies, and viewpoints which no one could discuss completely even in a short book; however, certain core themes remain valid to this day.
In order to survive, in the long-term, we need to meet two core challenges:
(1) Car fuel: we need to continue to find larger and larger affordable quantities of fuel for cars, trucks, busses, etc., even as conventional oil supplies become more and more of a problem. This is once again an urgent short-term issue for the world, as we contemplate the relations between the Middle East and the industrialized world over the next two decades, and as we consider the needs of developing nations. The key “number” we have to watch is the supply of the specific forms of energy that we can use in cars.
(2) Primary Energy: we do also need to watch the “total energy” number. We don’t have to worry about having enough total energy right now, but we do have good reasons to worry about the price of electricity, the long-term trends, and our ability to hold down costs while also respecting the two constraints below.
The challenge is made much harder by the connections between energy and other sectors of the world. The survival of the human race is not just a matter of energy as such. In fact, issues of war and peace and weapons of mass destruction directly threaten our survival far more than energy does directly. Those larger issues depend a lot on issues like education, population, water, food, spiritual culture, biodiversity and the role of women which are far beyond the scope of this essay. The key challenge in the energy sector as such is to improve the two “numbers” above, while also respecting two key constraints:
(3) Environmental Sustainability. The most important single number we need to worry about is
the amount of CO2 in the atmosphere. Yet as we chart the near-term pathway to a sustainable future, NOx emissions and stratospheric ozone also matter a lot. We may debate the importance of these numbers and how it varies over time, but certainly these are major global concerns.
(4) Global Nuclear Security. Scenarios have been considered for meeting all the energy needs of a growing world economy, across all sectors (not just today’s electricity use), based on conventional local nuclear power plants. In the Middle East, for example, economics would almost certainly require a massive use of local construction companies such as Bin Laden enterprises or certain famous Russian and Chinese all-purpose export companies. But it is questionable whether the world is currently able to manage even the much smaller flow of nuclear materials and technology across Eurasia today; there is a compelling national security reason to do our best to avoid a growth in the problem by orders of magnitude.
In summary, our survival depends on our ability to think hard about the four key “numbers” here. It will be very difficult to keep all four numbers on track, in the long-term, while still providing for the essential growth in the world economy. The main goal of this essay is to reassess where we stand in trying to keep these numbers on track – to achieve global energy sustainability.
Before I get into the details, however, I should address some concerns that some people might have about this problem statement.
First, I do not claim that energy sustainability is the only challenge before us. For example, the gap between rich and poor is growing in some areas (e.g. US versus Africa) but shrinking in others
(e.g. Japan versus China). The world does need to address other dimensions of sustainability. But energy sustainability is one of the key requirements for human survival in general.
Second, there are other issues which the economy needs to address in the energy sector. We will need to provide aviation fuel and feedstocks for plastics, for example. We will need to provide an optimal mix of incentives to give consumers the benefit of all available energy technologies, not just the big ones which allow us to keep the Big Four Numbers in balance. But if we do not keep the Big Four Numbers in balance, our economy dies, and the fine-tuning is for naught. This essay will focus on the Big Four Numbers, and complicate things only when it is really necessary.
Third, with due respect to Amory Lovins, I do not really believe that conservation and small-scale renewable would be enough to balance the Big Four Numbers. Aggressive conservation technologies will be a major part of this essay – but the biggest potential for conservation comes from identifiable large-scale technologies that will be part of this discussion. The most sober studies have consistently shown that the smaller-scale stuff is like the fine-tuning mentioned above. For example, technologies like hydropower can be very important in some areas, like Brazil, but
its potential is very far from what we need to balance the four big numbers for the world as a whole.
The fine-tuning deserves support and attention, but it is not enough to solve the basic problems here.
Fourth, you may notice that I used the phrase “essential growth.” Many economists have noted that GNP as such is a very poor measure of human well-being. There is a huge literature on alternative indices or measures of human well-being. Clearly it would be grossly irrational for the governments of the world to straight-jacket humans everywhere, to force them to become an ever more robotic workforce in a quasi-military crusade to maximize GNP. This would be a gross parody of the values of human freedom and human sovereignty which are the historic roots of free-market economics. Nevertheless, in practical terms, the world will still need growing supplies of energy in order to provide more decent choices to a majority of the people on earth, even if we firmly resist the extreme forms of materialism.
Fifth, I will not be discussing any options for gross distortion of market economies. Occasionally governments have attempted to use compulsion or quotas to force people to use technologies which cost much more than politically incorrect alternatives. There are some incentive structures which do need to be revisited, but the goal here is to discuss new technologies and other options which are aimed at getting results within a market-oriented economy. Technologies which cost more than the alternatives, without proving some other important benefits to the consumer, will not be proposed. The word “we” should be interpreted to mean “we” human beings, not “we” U.S. government officials; we human beings have a lot of work ahead of us.
Sixth, this paper is being updated in July 2004, in order reflect a few of the key points which have emerged in the intense follow-on discussions within various nodes of the Millennium Project.
In summary, the main challenge before us is the same as it was 20 years ago – to push the same four numbers we had to worry about 20 years ago. But the options and technologies before us have changed dramatically. The time is ripe for a radical reassessment.
Because energy options are so complex and varied, we must be very careful in how we phrase and understand the key questions here.
I will focus on three key questions of interest here:
(1) How could we someday zero out the net CO2 emissions which result from powering a growing fleet of cars and trucks?
(2) How could we keep these fleets going when natural supplies of oil (including tar sands) start to “run out” (rise to prices beyond what the economy can bear)?
(3) What could be done to get us from where we are now to complete sustainability by these measures?
In the next subsection, I will focus on the first two questions. These questions may seem narrow, in a way, to some energy economists – but it is essential to focus on very specific questions, to begin with, because of the enormous complexity of the world energy system. The following subsection will address more of the complex near-term challenges.
Many futurists have argued that the answer to question 1 and 2 is simple: that we must shift over to a “hydrogen economy.” The “hydrogen economy” is a very broad and complex “meme.” (See the National Hydrogen Plan and the National Hydrogen Strategy posted at http://www.eere.energy.gov/hydrogenandfuelcells/ .) In this section I will focus more narrowly on the core hypothesis of that vision: that we should plan for cars and trucks which carry hydrogen as such on-board as their primary source of energy.
Hydrogen storage on-board cars seems at first to be a very serious option here. If we can make it work, either with fuel cell or combustion engines, we end up with zero CO2 emissions from cars. And we don’t need gasoline to put in our cars.
But there are at least four other ways to zero out net CO2 which merit very serious consideration, in my view: (1) electric cars; (2) continued use of carbon-based fuels coupled with recycling of CO2 from the atmosphere (or upper oceans); (3) use of carbon-free fuels like ammonia which easily be “reformed” to generate hydrogen on-board a vehicle; (4) use of “thermal batteries,” which can store heat in a car for later use by a heat-to-motion engine, like the new STM system described at www.stmpower.com.
In this section, I will discuss how we can explore and use these 5 key technologies in the coming decades. But first I owe you two caveats. First, there are some higher-risk technologies, like wind-up cars and compressed air and others, which have some very intense enthusiasts. Many of these do merit continued high-risk exploratory research, in hopes of a breakthrough. However, the latest information I have seen is not yet enough to warrant putting them on the “A list” of technologies which might provide the foundation for assured survival of the world economy. This list has changed over time, and we need to be ready for further changes – but I don’t see them there as yet, based on any information I have had access to. Second, there are some options, like toluene as a hydrogen carrier, which are hard to classify here; if they aren’t reformable, and they don’t lead to CO2 emissions from cars, I would classify them as part of the hydrogen economy option.
Which of these 5 technologies offers the greatest long-term hope of holding down the cost of car fuel?
We really do not know as yet which of the five will work out – if any. Detailed life-cycle cost estimates are extremely speculative at this time, when we don’t even know the best way to implement any one of the five. A rational strategy for developing these technologies would rely heavily on concepts like decision-tree analysis and “buying information” to reduce uncertainties, in the spirit of wildcat drilling. But we can learn a lot by doing some straightforward comparisons. The comparisons in this paper could be refined much further by more careful analysis of the concrete issues raised here– but even these simple comparisons are enough to bring out the strategic picture we are facing.
First of all, we may ask – if cars use hydrogen, in an “ultimate” scenario using no fossil fuels, where would the hydrogen come from, and how would it be transported?
There are two obvious large-scale nonfossil sources of hydrogen: (1) use of primary energy sources, like nuclear plants or solar heat or photovoltaics or wind, which can also produce electricity at a comparable or better efficiency; (2) processes based on artificial or bioreactor photosynthesis, like biophotohydrogen. (Conversion of ordinary biomass, like wood or corn husks, to hydrogen would not have a potential scale of output relevant here, because of limits to the sustainable supply of such biomass [OTA report].)
If the first of these sources wins out, then the best way to transport the hydrogen to market would be indirect. Instead of transporting the hydrogen directly as a gas, it would be far cheaper to make electricity at the source, send it to the market over the electric power grid, and convert the electricity to hydrogen at or near the “gas station” by electrolysis.
Why not transmit the hydrogen by pipeline instead? The National Renewable Energy Laboratory (NREL) has published numbers for hydrogen pipeline costs which seem plausible, at first. (See C. Padro and V. Putsche, Survey of the Economics of Hydrogen Technologies, NREL/TP-570-27079, September 1999.). However, the citations which go with their discussion clearly establish that pipelines of a given volume could only transmit half as much energy as natural gas pipelines of the same dimensions. Well-established hydrogen embrittlement problems (cited but not incorporated into the estimates) would probably double costs again or more. If we consider how many billions of dollars and years (and energy losses) went into the gradual buildup of the US natural gas pipeline network, and then multiply by four or more – clearly this would not come cheap. By contrast, the US already has a massive electric power transmission grid which is used up to capacity only at times of peak load. Why should we pay hundreds of billions or trillions of dollars for a transport service we could obtain almost for free? Furthermore, why should we wait for the decades (at best) to build a new infrastructure, when we already have one available today?
There are two reasonable counterarguments here.
The first is that some sources of electricity are very hard to connect to the electric power grid at present. Certainly we have heard stories about wind generators that effectively delivered negative energy to the grid, when they were hooked up in a naïve fashion. But competent power engineers, like Mohammed El-Sharkawi of the University of Washington, have also reported how they were able to go back and fix the hookups to substantially reduce such problems. There is a new paradigm for electric power grid control, dynamic stochastic optimal power flow (DS-OPF), which ought to be able to overcome these old problems – and also give proper credit and payment to small-scale generators of electricity. (See J.Si et al, eds, Handbook of Learning and Approximate Dynamic Programming, Wiley and IEEE Pres, 2004.) Certainly the development and deployment of this kind of technology should be a priority in the quest for energy sustainability.
The second argument is that the energy losses in electrolysis might outweigh the many costs (including some level of energy losses) in hydrogen pipelines. I must confess that I do not have numbers here. Chemists for years have reported efficiencies near 100 percent for known electrolysis processes – yet DOE is investing heavily in reverse fuel cells and the like expected to achieve efficiencies more like 80 percent. By analogy to other such systems, I would guess that the discrepancy is a matter of scale. Thus one could imagine hydrogen being made from electrolysis at a metropolitan level, to capture the economies of scale, and moved around very locally, most likely by truck, or else being produced literally at the gas station. The whole scheme requires very good hydrogen storage in vehicles in any case. One may debate the relative likelihood of the metropolitan option versus the gas station option, but it seems reasonably likely that one or the other would be efficient enough to outweigh the huge costs, delays and problems with long-distance pipelines. (Note added in August 2003:
Gene Berry of Lawrence Livermore has explained to me how it is easy to get circa 65 percent efficiency, and approach the theoretical 80+ percent limit, using small scale electricity-to-H technology very familiar to some of us; very large facilities inputting an optimal mix of heat and electricity can do better in theory, but the overall economic advantage is speculative and questionable, and marginal at best. Many earlier more optimistic numbers were based on misleading ways of measuring efficiency.)
This then leads to an obvious question: if we are using electricity from the grid to make the hydrogen, why not insert the electricity directly into the cars instead? Wouldn’t this save a lot of wasted energy in conversion back from hydrogen to electricity on board the car? If energy efficiency were the only consideration, one might expect that electric cars would win over hydrogen, hands down, if the hydrogen ultimately comes from the kinds of primary energy sources I just discussed.
Before discussing the other considerations, let me go back to the other possible renewable source of hydrogen – biophotohydrogen. How might that change the equation here? I have heard estimates of efficiency for photosynthesis ranging from 3 to 8 percent – all much less than the 30 percent or so achievable by proven solar thermal technologies, like the Sandia solar thermal technology using the SAIC design for mirrors to concentrate light and STM systems to convert heat to motion and electricity generation. One may ask: how could biophotohydrogen have any hope of competing with that, assuming that the cost per square yard of mirrors will always be much less than the cost per square meter of biocultures? In fact, the NREL cost estimates for biophotohydrogen show grossly noncompetitive costs – except for a kind of placeholder number for hopes of a certain set of high-risk breakthroughs. (See Wade Amos, NREL, Cost Analysis of Photobiological Hydrogen Production From Chlamydomonas reinhardtii Green Algae, September 2000.)
Included in those proposed breakthroughs is a concentration of light, by mirrors, into a bioculture which is asked to function under 10 to 100 times as much light as we normally encounter on earth. It would certainly not violate the laws of physics (so far as we yet know) to develop organisms capable of such novel and useful behavior, but this is certainly an area for high-risk basic research, with no guarantees of ultimate success. It would be a major challenge to develop new kinds of adaptive nonlinear control powerful enough to keep organisms alive and functioning under the unique and stressful conditions
envisioned here. Conventional adaptive control would almost certainly fail, because bioreactors are generally “nonminimum phase plants.” (A lengthy example was discussed by Lyle Ungar of the University of Pennsylvania in the NSF workshop on biocontrol back in 1990 organized by Peter Katona.) Linear robust control can work well enough if the plants are close enough to linear and disturbance-free, but the chances of that do not seem encouraging here. However, Donald Wunsch of the University of Missouri Rolla has a paper forthcoming in the IEEE Transactions on Neural Networks which reports success with a new nonlinear intelligent control scheme for bioreactors. There may be hope, if we press the technology hard enough. Or not. But we are critically dependent on researchers able and willing to break out of the existing established paradigms. It is much harder to find researchers able to do this than researchers who promise it. Many more traditional control engineers would be far less optimistic than myself, when confronted with this kind of plant.
If biophotohydrogen should be workable, in the end, what would that imply for the larger picture?
First, we could expect that artificial photosynthesis would also provide a way to extract CO2 from the air (or from surface level seawater). The net benefits would be the sum of two main products – the hydrogen production and the CO2 removal. Second, biology suggests it should be far easier to produce carbon-based fuels, using this CO2 extracted from the air, than to produce hydrogen. (Indeed, the NREL reports on biophotohydrogen makes it clear that the processes they are looking at are far more complex and esoteric than the vast, prevalent normal mechanisms for organisms to produce carbon compounds). If biophotomethanol were used as a car fuel, instead of hydrogen, we would still end up with zero net CO2 emission – but we could use the existing world infrastructure for handling liquid fuels, and our chances of success would be far greater.
Now let us consider these tradeoffs more carefully. If the economy chooses any of the four options discussed so far – electric cars, hydrogen produced “at the gas station,” biophothydrogen or biophotocarbon fuels – net CO2 emissions go to zero. Thus in any of these long-term scenarios, the net value of further CO2 reduction goes to zero in the long term. Once the CO2 premium goes to zero, I would argue that biophotomethanol totally dominates over biophotohydrogen, in economic terms. Methanol can be used in fuel cell cars, just as hydrogen can; decades ago, Pat Grimes (then at Allis-Chalmers, writing in the AlChe Proceedings) demonstrated a direct methanol fuel cell with higher efficiency than the well-publicized hydrogen PEM fuel cells reported in recent years. The efficiency penalty of using methanol instead of hydrogen may be as much as 10 percent, for optimally designed cells, but transport losses in hydrogen would make up for that; more important, the fuel storage and transport infrastructure of methanol provides a huge advantage over hydrogen, and production may be easier (Other carbon-based fuels would impose a major additional efficiency penalty relative to methanol in use onboard optimally designed fuel cell cars, because small-scale efficient steam reformers cannot be used with them.) Mirna McDonald of Penn State University, under a small grant from NSF, working with Grimes, has recently replicated some of Grimes’ technology for carbon-tolerant alkaline fuel cells, which appear to promise far lower costs, higher efficiency and longer lifetime than the more better-known PEM fuel cells; likewise, related work reported at www.electricautos.com may contain important complementary technologies.
In summary, the long-term economically plausible alternatives seem to come down to three – electric cars, hydrogen produced from electrolysis at or near the gas station, and biophotomethanol. (There are also the two more esoteric options mentioned earlier, which I will discuss later in this section.)
What will drive the tradeoffs between these three? What kinds of research and other efforts would give us the best chance of realizing the full potential of all three?
Let us first re-examine the electric car option. After the great oil shock of 1979, public enthusiasm for electric cars became enormous. Startup companies without previous experience in making cars marketed a number of instant electric cars, with performance so bad that many people now start out with a very large irrational bias against this technology. More serious manufacturers, like General Motors, worked hard to develop a more realistic, high-performance car – but even that car had problems.
Until recently, conventional wisdom amongst energy experts ruled out electric cars on two grounds: (1) cost, both of batteries and of supporting technologies like power electronics and control chips;
(2) limited driving range, due to low power densities in batteries.
But now things have changed. Not only electric cars, but fuel cell cars and conventional hybrid cars make heavy demands on power electronics and control systems. (Indeed, pure electrics tend to be simpler than these others.) Years ago, those same cost factors made hybrid conventional cars unaffordable.
When the new Honda and Toyota hybrid cars first appeared on the market, the automotive grapevine said that these companies were swallowing or subsidizing as much as $100,000 per car, just to build up an early market and invest in experience. But as a result of that experience, Honda is clearly marketing hybrids on a much larger scale. Cost subsidies are highly proprietary information – but the grapevine now says that subsidies may be near zero now, and this seems to fit Honda’s marketing behavior here. Likewise, it is said that other companies have begun to catch up to some degree. In summary, the biggest cost problems which made all these cars unaffordable have been overcome.
But what about the batteries themselves? Costs and energy density of batteries remain an issue. The best well-established batteries would still impose a significant cost penalty and driving range penalty, relative to today’s gasoline cars. However, the same is true of hydrogen fuel cell cars using any plausible extension of the well-established hydrogen storage technologies, such as compression or liquefaction, which also impose energy losses! Roughly speaking – if electric cars save us the energy losses in electrolysis, in local hydrogen transportation, and in converting hydrogen back to electricity, and if the cost and storage loss problems are comparable, electric cars would appear to win over traditional hydrogen cars. Except for one other problem of electric cars, which I will discuss in a moment.
New technology developments suggest that this picture could be changed radically in the near-term future.
Given the facts above, the main hope for hydrogen cars to compete with electric cars lies in the hope of new forms of hydrogen storage on-board vehicles. If hydrogen cars and infrastructure based on existing technology have almost no chance of making it in the marketplace, then research efforts really need to focus on exploring radical high-risk storage options which have a solid hope of overcoming that barrier. (Though electrolysis and fuel cells clearly play an important role as well.) Heavy investments in more conventional hydrogen technology may be compared to huge government investment in improving lead-acid batteries in the 1980s.
So far as I know (as I try to track and evaluate fast-breaking fast-changing information), hydrogen storage based on carbon nanotubes is the only form of hydrogen storage so far which has demonstrated good enough energy density in solid prototype systems, and plausible performance. Professor Vijay Varadan of Penn State University has demonstrated small high-density nanotube storage systems, aimed at present for high value added markets like small medical and computing devices. Conventional carbon nanotube material is far too expensive for use in volume in cars, but Varadan has leveraged advanced research in microwave and MEMS technology to develop a relatively low cost manufacturing process and plant. It is far too early to feel confidence that manufacturing costs (and other issues) can be ultimately solved here, for use in cars – but clearly this should be a high priority direction for research. In my view, this line of work represents more than half of the real hopes for a hydrogen economy, and it would be a crime to fail to do full justice to it. Common sense suggests that there might be comparable high-risk high-potential options out there, but the few I have seen any sign of (such as an effort at the Jet Propulsion Laboratory) seem to be much further out in the tree of risks and required breakthroughs; they merit funding, but not at the same level as the nanotube option.
On the other hand, it now looks as if the breakthroughs on the horizon for batteries are even more exciting. At a recent workshop on nanotechnology and energy, at the Woodrow Wilson Center in Washington D.C., representatives of Solicore displayed a new solid electrolyte for batteries, exploiting nanostructured materials, which may possibly be all we need here. Solicore compared the new battery capabilities against the best established lithium battery designs. In general, it sounded like a doubling of lifetime (thus halving cost flows) and of sustainable energy density. Because exact numbers were not given, there are still significant uncertainties here (though not as vast as the open questions about nanotube costs!). However, it was stated that licensing agreements had been signed for batteries large enough for use in cars, and that Quebec Hydro and others were actively following up on commercialization. (See www.avestor.com). Some of these claims have not been independently verified; however, many researchers in nanotechnology note even more promising results in more aggressive technologies, using nanoelectrodes and the like; however, there are lifetime issues to worry about. It is even conceivable that the ultimate car of the future might even be a battery-heavy methanol fuel cell car, able to save money by charging up for short trips but able to use methanol for longer ones.
In summary, the odds do appear better than 50-50 that new breakthroughs will increase the advantage of electric cars over hydrogen. Again, however, we should remember that the examples discussed here are really just the first wave of a very large family of new technology, which may well succeed even if the first examples should develop glitches. We certainly need to continue exploring the hydrogen option, just in case the nanotube storage works out and the new battery does not. It is far too early to really know. However --- if Solicore should publish and verify good enough numbers in the near future, it may then become time to conclude that electricity would certainly have a large role in fueling cars in any efficient sustainable energy economy.
What about biophotomethanol? Even if biophotomethanol should work out, at an affordable cost and a large scale of production, it would entail losses in its use in a fuel cell car, even a bit more than hydrogen would. It is hard to believe that biophotomethanol could really become cheaper per Btu than mirrors and solar thermal systems using the same amount of light. Thus if the nanotubes really work out, hydrogen solidly dominates biophotomethanol as a long-term sustainable car fuel. If they don’t, but if the batteries work out, electricity has all the same advantages over biophotomethanol that I just discussed for electricity over hydrogen. If neither batteries nor nanotubes work out, we will desperately need that biophotomethanol as the main fuel for cars. It is possible that more advanced biological technology could someday be used mainly to capture carbon atoms, and that solar energy (heat and electricity, in effect) could be used to maximize methanol production per carbon fixation.
This leaves us with two further questions for this section: (1) what was that other disadvantage of electric cars, and what are ITS implications?; (2) what if all three high-risk options become problematic technically?
When electric cars were very popular in the 1980’s, extensive studies were done of many, many technical issues in bringing them onto the road. Now that the range and cost issues have been resolved, we need to revisit all these issues in great detail, to see what they imply. Certainly the success of General Motors in building a high-performance (if expensive) electric car should be a starting point of such a reassessment. Given that I have not studied the relevant GM documents, I do not know whether they have in fact solved all the hitches. If so, and if Solicore proves its case, we would be foolish not to go whole-hog towards electric cars, in my view. From a distance, I have the impression that most of the ordinary design problems were solved – except perhaps for one. The one which worries me (in my ignorance) is the issue of recharge time away from home. (As this goes to press, Prof. Ziyad Salameh of the University of Massachusetts at Lowell tells me he has demonstrated a system for full recharge
in 12 minutes – but that there is a serious chance of doing much better with new intelligent control approaches.)
On ordinary work days, electric car owners could recharge their cars overnight, using low-cost off-peak electricity (very low price if grid control is made more efficient). They would save a lot of money, especially in a future where oil prices are allowed to rise very high. If the new batteries give them a driving range of 300 miles or much more, this by itself should be enough to provide a large market segment, in an efficient economy. But what happens when people try to drive much more than 300 miles, on a long trip? How quickly can their car be recharged away from home? Considerable research has been done on options like fast-recharge electronics (some claim recharge in 5 minutes), or gas stations which swap battery parts or whole batteries. Perhaps this is a completely solved problem. Or perhaps not. Probably the special characteristics of the Solicore battery would need to be studied, to see how it lasts when subject to various types of fast recharge. Perhaps the neural network battery modeling and optimal scheduling used on other batteries may be relevant here – requiring new research to really nail down the new option. Or perhaps, if worse comes to worst, we will need to think about battery-heavy hybrid fuel cell cars, able to recharge overnight on normal days, but able to use methanol or hydrogen bought at gas stations when one is taking long trips. (In such a hybrid design, conventional hydrogen storage would “bust the budget” for such an auxiliary system.) Such battery-heavy hybrids may also solve some glitches in traditional fuel-cell cars, such as problems in start-up time.
Finally – what if all three high-risk technologies fail – breakthrough batteries, nanotubes, and biophotomethanol?
If we had no other choices, and we had to zero out net CO2, probably we would simply have to swallow the existing best electric car technology, warts and all. After all, carbon-based fuels would be out, and we would be back to today’s battery versus cryochamber tradeoff. But on paper, at least, ammonia provides a strange but highly reliable alternative, allowing the kind of driving range and refuelability consumers demand today. Grimes and Kordesch (see Kordesch’s book on fuel cells) and collaborators have built functioning ammonia cars and other vehicles. Ammonia is feared for safety reasons – but all high-energy-density materials present some degree of safety issues. The world has shown that it is willing to accept the risks of gasoline, to achieve high performing cars, and there is every reason to believe it might be similar for ammonia, if the alternatives do not work out. Ammonia can be reformed to hydrogen on board a car even more easily than methanol, and it contains no hydrogen to emit. We certainly know how to make it on a large scale from air and energy, as demonstrated in innumerable ammonia plants around the world. It is a liquid fuel. Nevertheless, there would be major costs in transition to ammonia, and major delays; we may hope that the new breakthroughs in nanotechnology will eliminate the need for such a backup. At the same time, perhaps we should work on the long-lag elements of a transition to ammonia, just in case it becomes necessary.
(During Millennium Project discussions in 2003, I reconsidered this. If cars and trucks account for about 1/3 of CO2 emissions today, and if use of new advanced types of methanol fuel cell cars would reduce CO2 per mile by a factor of 3, we could reduce CO2 by a factor of 9, and not have to worry about problems in using methanol for a very, very long time.)
In a similar vein, STM power has argued that thermal batteries could be used for storage on-board cars, combined with their new external Stirling-derived engines. The latest STM designs for mass-produced inexpensive engines would only have about 40 percent engine efficiency – a bit better than the real-world whole systems performance of PEM fuel cells, but far inferior to electric motors. They claim that thermal engines built so far have shown about 20 percent energy losses in storage, but an energy density far better than batteries and adequate to the wants of today’s car drivers. They also claim that STM efficiency could be raised to as high as 60 percent (like a good fuel cell), with further research into improved materials, and that thermal batteries could also be improved. On balance, it may be about as good as ammonia. It is too early to predict how good it could become. More research is clearly called for, especially since STM systems have important potential in other sectors of a sustainable energy economy.
In summary, it is too early to pick a “winner” between the five options here for a zero-net-CO2 car fuel. All five show serious promise, but merit far more well-focused research than they are receiving today, despite the huge investments in energy technologies which are less relevant to the goal of long-term sustainability. All five would have the secondary benefit of freeing us from dependence on fossil fuels (and OPEC) for car fuels; that in turn would have truly enormous benefits in helping us avoid global wars. The most critical need is for expanded efforts (in money, support, attention and other resources) for critical emerging technologies now being funded at a very tiny scale, such as nanomaterial batteries, manufacturing of nanotube hydrogen storage, dynamic stochastic OPF grid control, intelligent battery management and recharge, biophotomethanol, and improvements in thermal batteries and biophotomethanol. Large scale industry-government cooperation in developing contingency plans and incentives for deployment will also be critical.
The real-world issues connecting today’s energy economy to the long-term future of car fuel are far more complex than the end point itself. They are so complex that many people would naturally recoil into a shell of robotic, procedural behavior or ideological thinking, because it is not so easy to think about these complex life-and-death problems in a complex, realistic way. That makes it all the more important that those of us who are firmly committed to staying alive focus on the larger context, and think harder about what can be done.
To begin with, of course, comes the question: “Is this really a life and death issue? And if so, on what time scale?”
The importance of CO2 itself remains a matter for debate. Many believe that continued rises in CO2 would indeed inundate some areas within a hundred miles of the ocean, and dry up (or flood) some farmlands, causing on the order of a trillion or a few trillion dollars worth of damage over a century – but on the scale of a century, humanity could survive that. A carbon tax large enough to cut CO2 emission in half under present technology might cause more economic damage than that. (Circa 1980, I urged the EIA to include a carbon tax scenario in the Annual Energy Outlook; the results were not so encouraging for the idea, but they were very well grounded in deep EIA-wide analysis of the real-world drivers of energy demand and economic growth. If anything, they were on the optimistic side, relative to later analysis.) Nevertheless, industry needs to be realistic about the seriousness of the public and political problems that could result if an efficient way to lower CO2 is not pursued. We can develop alternatives to present technology and trends. We do not have to limit ourselves to the carbon tax idea.
But it’s not just CO2 at stake here. It’s also the availability and price of car fuel itself.
There was an important international conference on energy and sustainability, jointly assisted by the energy industry (particularly PEMEX) and by the Millennium Project of the United Nations University, led by Prof. Oscar Soria-Nicastro at the University of Carmen (UNACAR) in Mexico in June, 2003. (See prospectives21carmen.org.mx for details and presentations.) The presentations included an extremely impressive presentation by Ismail Al-Shatti of the Persian-Arabian Gulf institute for future and strategic studies, which has access to the very best information across all sources and viewpoints in that area.
Al Shatti weaves together a number of complex strands of politics and economics which are sometimes hard to integrate when viewed unsympathetically from a distance in the West. The message is not one that many of us would enjoy hearing – but we should be grateful to the messenger for helping us come to terms with reality. Part of the reality is that the whole world risks paying a severe and unbearable price if we do not cut heavily into our dependency on oil in 20 years time. We need to fully understand and assimilate this message, including those challenging parts which are beyond the scope of this paper.
Above all, we urgently need to understand more clearly how severe the timing problems are here. Since Al-Shatti already accounts for phenomena like hybrid cars and undiscovered oil, we would need much more to change the situation in 2025 by much. (Similar or equivalent bleak forecasts come from other sources like Cavallo of the US Department of Homeland Security, former DOE, using USGS estimate of undiscovered recoverable oil, and from IEA, Shell, etc.) However, because cars stay on the orad for an average of 15 years, we would need (roughly) all new cars sold in 2010 to be gasoline-independent in order for half of the cars on the road to be that way by 2025! It is not realistic to imagine all the new cars being electric, hydrogen or dediucated natural gas vehicles by 2010!!! Our situation is grave indeed, and it leaves us with few safe choices.
Many people have assumed that the “chicken-and-egg” problem of providing a new fuel and providing cars that use that fuel is the biggest difficulty in moving towards a world of sustainable car-fuel. But the conflicts of political and economic and military interests (and the resulting biases and misperceptions and conflicts of opinion) may actually be a bigger challenge.
These conflicts are far too complex to treat exhaustively here, but there is one key variable we can start out with – the world oil price.
Some economists believe that the world oil price today is highly irrational and “subsidized.” According to free market economic theory, it is highly irrational to price a limited scarce resource at the marginal cost of production; it is important to add in the scarcity rent. When future conditions are unknown, the scarcity value should be augmented to reflect the “insurance value” of having the resource available in the ground. Political distortions and political distortions of interest rates (interest rates which are often set at high levels in order to allow governments to borrow more money) have a heavy effect on the price.
This view is highly debatable in the West, though I for one tend to agree. Within the OPEC nations, however, people would extraopolate all this much, much further than I would. One of the deepest analyses of Al Queida (Through The Enemy’s Eyes, by Anonymous) reports how deep and pervasive are the feelings that the West is stealing Islamic oil at unfair garage-sale prices, enforced by military means and corrupt regimes. Yes, there is some extreme misperception there – but we in the industrialized world need to come to terms with our own biases and wishful thinking; we need to plan for a future which fully accounts for the realities of the Middle East. For ten or even twenty years, petroleum diversification will limit the pressure on us from OPEC – but we may need all twenty of those years, in order to minimize the probability of an unsustainable collision. Bear in mind that this discussion refers to the possibility of problems with the Middle East becoming far more difficult than they are today.
No matter how hard we work on global dialogue and peacekeeping, the chances of preventing greater global conflict will be very small if we all turn into hungry rats fighting for the last piece of cheese; I would not want to be one of tose rats – and I wouldn’t want to be the cheese either!
A traditional economist might well respond by saying: “OK, let’s just cool down, and let the market solve all these problems. Let’s just get rid of the distortions, and let the price of crude oil triple or so. That will create all the incentives you would need to bring the new car fuel technologies online. As it rolls in wealth, the MidEast will be happy too.”
An alternative approach is to admit that oil users and oil producers both face huge uncertainties and grave worries here – and that both sides could gain from a “global compact” that shares risk on both sides, by something like a treaty that: (1) no one will sell crude oil below $30/barrel (in 2004 dollars) ever again; (2) we will all work together as hard as we can to prevent the kind of scenario that Al-Shatti has depicted.
Many economists – including economists in the energy industry – were very optimistic about the more traditional approach, back around 1979-1980, when oil prices were indeed allowed to rise substantially. But it did not work out so well. In the real world, high oil prices led to major (and perhaps unavoidable) political problems in the industrialized world. They led to massive economic impacts, not just direct but indirect. (Unfortunately, many econometric models were not well-designed to capture all the effects. The Wharton Annual Model did capture the gross short-term indirect effects, and the Dale Jorgensen model captured some of the investment effects, but there was no major model which captured both. There were also some industrial sectoral impacts observed by myself (Energy paper) and Marlay (Science).) They led to clumsy efforts at political fixes of all kinds which may have made transition to sustainability harder. Clever oil ministers in Saudi Arabia and elsewhere soon realized that it would do no good to just kill the customer, whatever economic theory might say; deep world depression and lack of growth would also cut back on oil demand and cause other problems.
In my own talk at the Carmen conference, I proposed the following approach to the OPEC world: If we can’t have a true free-market price, let us start thinking (conceptually, not legally!) about a kind of “two tier” pricing approach. Let us try to work toward a proper, higher price for world oil – while working in parallel to allow the customer to survive and bear that higher price, by having more and more availability of an alternative way to power cars, especially for ordinary people who desperately need to get to work every day. A kind of a balance. (Technically, the idea is to exploit and foster segmentation of the markets now served by oil. Some segments can afford to pay more than others. Those who would pay more should bear in mind that they do benefit from having oil available to them further into the future.) In such a regime, many other producers might aim to sustain the same level of short-term revenue by equalizing price rises and production cutbacks, thereby being able to continue oil production further and further into the future without a loss in revenue. Even the most intense efforts to increase alternative fuels would be barely enough to maintain this kind of dynamic balance, as oil prices try to rise in the years ahead. It would be nice if we could all work together on this. It would make particular sense to accelerate the switch to alternative fuels in developing economies where the ability to pay for oil is limited, and the damage to pre-existing interests would be less. I would regard this as a kind of “Pareto optimal solution,” where there is a bigger economic “pie” and therefore everyone can have a bigger slice, if we can begin to share this kind of vision.
But: how do we translate all this into technical market reality? What about those chicken and egg problems, and so on?
The technical transition will depend on many parallel actions by many different actors. Since there is no special order dictated by logic, I will begin by discussing the role of the coal and gas industries, major players which I have not even mentioned by name so far.
No one proposes to carry coal on-board a car, for many reasons. But coal will play a critical role for years to come in the transition to alternative car fuels. For example, holding down or lowering the price of electricity will be crucial to the market prospects of electric cars, or of hydrogen cars based on hydrogen from electrolysis. If we could make greater use of coal to provide electricity to places like California, we could reduce the true cost of electricity very substantially, perhaps as soon as one year in the future if there were not substantial nonmarket obstacles to serving the needs of consumers in those areas. (The price now being paid by California consumers is much less than the true cost, because of massive subsidies paid by the state of California – subsidies which are playing a role in the ongoing bankrupting of the state budget.) NSF and the Electric Power Research Institute (EPRI) held a workshop in Palo Alto in October 2001 to evaluate these problems and possibilities, and suggest concrete possible solutions. Preliminary information is available on the web site of Prof. Chen-Ching Liu of the University of Washington. An analysis of the major conclusions, with some additional information from a follow-on workshop co-sponsored by Entergy and from the Brazilian power industry, is expected in late summer or early fall 2003, under the leadership of my new NSF colleague Dr. James Momoh. Research on clean coal and on removing CO2 from smokestacks sponsored by DOE complements these efforts in an important way.
Coal can also be used to produce hydrogen directly, as can nuclear power, but this does not sound so exciting, after the discussion of the previous section. Many of the proposed technologies are very close to the famous synfuels projects of the defunct Carter initiative on synfuels. The termination of that program may have been influenced in part by an analysis of cost growth in synfuels technologies by Ed Merrow of the RAND Corporation, which I initiated and funded at EIA.
And finally, coal can be used in methanol production. Of all the synfuels technologies we evaluated in the 1980’s (not counting tar sands as synfuels), the most exciting by far was the Texaco Cool Water technology. Most synfuels technologies were a disaster in terms of NOx emissions, but Texaco avoided that by using high-pressure oxygen in place of air. Even more impressive, they actually had plants up and running close to market-acceptable parameters. As best I recall, the most interesting version (economically)involved CO-PRODUCTION of electricity and methanol. Not only could they produce electricity at market prices; they could then legitimately price their methanol at a level even lower than the low world market price at the time. For nations like China, blessed with huge stretches of abundant coal and serious problems in fueling a growing fleet of cars, this kind of technology merits more attention.
(Note in press: at a recent DOE-sponsored workshop discussed at www.agci.org,
it was agreed that CO2 sequestration from this specific type of coal-fired plant looks far more promising than any other route to CO2 sequestration. This may be our best hope for truly massive near-term reductions in CO2, above and beyond the changes in transportation proposed here.)
The production of methanol and electricity as coproducts from Texaco or Tennessee Eastman types of gasifiers has two big advantages over their use to make electricity: (1) because of the thermodynamics (matching heat and free energy), coproducts can achieve higher theoretical efficiency; and (2) by increasing the fraction of methanol at night, and increasing the frcation of electricity in the day, one can use these plants to track loads on the electric power grid – a crucial issue in the economics of electric power.
This leads naturally into the issues of how to get that methanol actually used in cars – but first I promised to say something about natural gas.
Advocates for natural gas have often worked hard to push the idea of using natural gas as a fuel in cars. In the past, they have mainly advocated putting gas canisters into a car, and piping the gas into an ordinary internal combustion engine. They have promoted this as a here-and-now opportunity to reduce dependence on oil. They have driven around real cars based on this approach, and have even arranged sales of conversion kits for conventional cars. This never got so far in the near-term marketplace. In the long-term, it is clearly not so efficient as using the natural gas to make methanol, and using the methanol in a well-designed fuel cell vehicle.
But what about using natural gas in a fuel cell vehicle? Many researchers, such as a group at Arthur D. Little, have developed fuel processors to convert natural gas to hydrogen on-board a car, to permit the use of a PEM fuel cell. But these fuel processors were extremely bulky, and they inherently use more energy than the simple, small steam reformers which can process methanol or ammonia. Likewise, gaseous storage presents issues with natural gas similar to the issues with hydrogen.
Nevertheless, though natural gas does not belong on the “A” list of options today, one could justify a certain stream of aggressive high-risk high-potential research to try to get it there. It is possible that intelligent control could make it possible to shrink the size of natural gas fuel processors. More important – there are high-risk options for fuel conversion, using approaches radically different from partial oxidation and the like, which might have hope of improving efficiency. And perhaps the same carbon nanotubes which Varadan is using for hydrogen might be applicable to natural gas as well. Or not.
If all of this should work out someday, it would simply allow us to use primary natural sources of natural gas efficiently and directly in a car – but it would not address the issue of CO2 production, and it would lead us into debates about how long the natural gas would last. Certainly natural gas is a premium fuel, like oil, and its price has begun rising again in reflection of its value. There are many debates about the possibility of huge sources (larger than the world’s coal supply) of natural gas deep below the oceans, but there is no debate about the fact that natural gas from such sources would be very expensive. Again, it is a high-risk option worth exploring, but the risks and costs are high enough that we need to aggressively pursue other approaches as well. Including options that would zero out the net CO2.
The discussion of coal and gas leads naturally to a key question: what can we do now to open the doors as soon as possible to a greater use of electric, hydrogen and methanol fuel cell cars?
If the new breakthroughs in batteries work out, the transition might be easier and faster for electrics than for the others. General Motors already developed an interesting marketing plan for its electric car a few years ago, and it did not depend heavily on new government actions. There was clearly a big market out there already for such cars, based on cars recharged from home electricity. If the new batteries allowed GM and others to sell such cars with a cost subsidy going to zero, there is hope for a true free market transition. More precisely, there is hope of a market growing fast enough that the next small steps would be relatively easy. Once the early adopter market is saturated enough that supply of electric cars starts to exceed demand, it would not cost the government too much money to ask for rapid recharge stations at key points along interstate highways; that by itself would take care of the problem of people trying to travel long distances, if rapid recharge technology is ready to go at that time. In the meantime, the main role for the government (other than supporting related research) would be to work harder to improve efficiency in electric power supply in general. The key short-term issues there have already been discussed.
Fuel cells – hydrogen or methanol – present a trickier transition problem. No one will buy hydrogen or methanol fuel cell cars in quantity until the fuel is widely available. But the fuel will both become widely available until there is a market. There are some heavy-handed government-driven possibilities available, such as mandating hydrogen use by large fleets and ordering them to make their gas tanks available to the public as well; however, such approaches are both slow and desperate, because of how completely they short-circuit the role of the market. More market-friendly approaches would be: (1) efforts to develop fuel cells which could even survive the use of hydrocarbon fuels, like solid oxide cells or alkaline fuel cells with new wrinkles (related to the earlier work of Grimes and Kordesch and others); (2) efforts to expand methanol availability without waiting for fuel cells. In my view, both approaches should be pursued in parallel – though the second seems more certain to be workable.
The use of hydrogen from electrolysis in an internal combustion engine does not seem realistic at all as a technology able to compete in the marketplace in the coming decade. But the availability of methanol really could be expanded dramatically, which would set the stage for a real-world market for fuel cell vehicles. That in turn is the fastest way to get fuel cell vehicles on the road in massive quantities, with a real market. Even if hydrogen should turn out to be better than biophotomethanol in the long term, we could GET to that long-term a lot sooner if we minimized the delay between now and the time when millions of fuel cell cars are on the road – even if those cars use methanol in the tank.
There is a major role for reasonable, market-friendly industry-governments partnerships in making methanol more widely available in gas stations, for use in internal combustion cars. For example, huge amounts of remote natural gas are being totally wasted – vented and flared – around the world, when the gas is an unintended byproduct of oil production. There is new technology for collecting that kind of gas at lower cost than before, and well-established technology for converting it to methanol. Groups like the World Bank could even set a priority on investments to capture this wasted gas as methanol, and get it into a distribution system.
Investments in such methanol production have been limited by the very low price of methanol on world markets. Such low prices do not provide a strong incentive in the short-term to additional production – but since methanol competes well with gasoline in price per Btu, one may ask why methanol has not already penetrated the car market more. This is especially true, since methanol is being used in very high-performance cars, like the Indy 500 cars, and many car drivers would actually pay a bit extra for high performance. The problem comes down to chicken and egg.
Back in the 1980s, experts like Roberta Nichols of Ford (now at UC Irvine) and Grey of EPA Ann Arbor, looked closely at the issues in using methanol as fuel in conventional, internal combustion cars. It is very unfortunate that their early work (then supported by people like Boyden Gary, General Counsel to The first President Bush) has been almost forgotten by key policy-makers in the wake of enthusiasm for fuel cells. In order to get to the fuel cells, we would first need to pave the road with these less exalted bricks.
In the 1980’s, serious analysts generally got past some of the lobbyists’ red herring issues about methanol safety and so on. Nichols estimated at the time that it would take $300 extra per car to make cars which are fully dual-fired, methanol-gasoline. A good part of that cost was the cost of gas tanks made from stronger materials, like stainless steel, able to resist methanol corrosion of the older materials. But in the meantime, new materials have been developed. From the auto grapevine, I hear that we have newer materials available today, which would just about zero out the premium for fuel flexibility in the gas tank and hoses and such. On the engine side, we now have new intelligent control designs and chips for vehicles (extremely useful for NOx reduction in my opinion, even without a fuel-choice driver) which would reduce the premium on that side. (NSF funded an SBIR project under Raoul Tawel of Mosaix LLC and the Jet Propulsion Laboratory which could be very useful here, for example; some additional details are in my chapter in J. Si et al, eds, Handbook of Learning and Approximate Dynamic Programming, forthcoming.) A more aggressive pursuit of these technologies, with some degree of government partnership, should allow widespread production of truly multifuel cars, with benefits to clean air, and relatively little cost premium. We could also build upon the learning experience from California in 1997, when the California Energy Commission and Ford partnered in an experiment which sold thousands of methanol-capable Taurus cars at no cost markup.
For practical political reasons, it would be essential for such vehicles to be adaptively able to handle methanol, ethanol, and various grades of gasoline. It would require government intervention to really push hard for such flexibility in all cars – but the result would be more of an open playing field in fuels in general. It would be essential, however, to maintain a higher level of technical integrity here than is customary in large lawyer-advocacy-style government programs.
Given the low wholesale price of methanol, and a growing number of such flexible cars, it should also require relatively force to make methanol available in a growing number of gas stations – especially in “extra pumps” where leaded gasoline is being still phased out in many parts of the world. Quality fuel tanks would be needed in gas stations, as in the cars themselves… but this is needed in order to prevent gasoline seepage into water supplies in any case!
Methanol does have a lower energy density than gasoline. I would envision a scenario in which the owner of a flexible car would get to decide, every time he or she fills up, which fuel to choose today.
“Should I spend 75cents per gallon of methanol and be able to drive 200 miles before my next refill? Or do I spend $3/gallon on gasoline or ethanol, but be able to drive 400 miles?” Perhaps he/she would choose methanol on most days, and save the gasoline for a day before a big trip. And perhaps poor people would use more methanol, while rich people would stick with gasoline or ethanol.
Many of the technologies discussed above could go ahead based on the usual mix of private sector investment and government support for high-risk research. However, because the situation is very urgent here, and because the world economy is not moving fast enough yet to deal with it, I personally would advocate two urgent matters of legislation: (1) that all cars placed into service after year X which are capable of using gasoline as a fuel must also be capable of carrying and using ethanol or methanol safely in the same gas tank; and (2) all incentives, subsidies and research opportunities which exist for biohydrogen or bioethanol should be extended to biomethanol. Year X would be two years from date of passage in most nations – but the US has elaborate certification rules which should either be relaxed for two years or used to justify a delay of four years.
Notice that such a law would still give consumers and producers the full freedom to choose, say, dedicated natural gas cars instead – but it is clear that retooling the materials used in gas tanks can be done in two years, while a heavy conversion to natural gas could probably not be so quick. The net effect is to slightly encourage natural gas, electric or hydrogen cars – but to ensure that all cars with gasoline tanks have stronger tanks, and that all cars have a way to operate without gasoline. The law is asymmetric, because tanks which usefully hold gasoline cannot also hold natural gas in useful amounts.
In summary, natural gas (especially remote gas) can play a key role here as a premium fuel, as a source of methanol, to displace oil, even in the next ten years. The potential is there for a very large displacement, even within ten years, if we really pay attention and take this seriously. The easier, lower-value task of generating electricity can then be shifted to other fuels, as will be discussed in the final section of this paper.
As for hydrogen – the methanol effort and hydrogen technology development would provide the best opportunities for near-term work. Transitions to ammonia or thermal batteries would be more difficult, and I have no immediate suggestions other than continued work on the underlying technologies. It is premature to consider government requirements for ammonia use (except perhaps in some special military applications, which the Army has researched) at a time when a more market-friendly approach based on electricity, methanol or hydrogen seems quite promising.
Even after we figure out how to power our cars and trucks, global energy sustainability requires that we ask one more question:
How can we find enough total primary energy to make the fuels we use in our cars, and to power the rest of the world economy, in a sustainable way, without violating the environmental and national security constraints?
Once again, there are many desirable technologies that can provide 2 percent here or 5 percent there, but even taken together cannot put us all on safe ground, in being able to meet total world demand when oil and gas drop off. Richard Smalley, the discoverer of the carbon nanotube, has conveyed this picture very elegantly and persuasively this year – but his conclusions are essentially the same as what other serious analysts have concluded. (Cite: Hoffert et al, Nov. 1 2002 Science; the same initial citations
in the beginning here; the Shell future scenarios discussed at prospectivas21carmen.org.mx.)
There are only four technologies which definitely could provide enough total energy to meet the world’s needs for decades and decades, as conventional oil and gas start to run out:
(2) earth-based solar power
(3) space solar power (SSP)
In effect, this is like the “A” list of five car fuels discussed earlier. As discussed earlier, esoteric natural gas also provides a reasonably plausible high-risk alternative, and biophotomethanol has some potential – but it seems that unlikely biophotomethanol could ever compete on cost with earth-based solar in producing electricity, which will almost certainly be the most important carrier for energy uses outside of transportation. There are other ideas for more radical technology which might or might belong on the list in the future. But to maximize our chances of achieving overall sustainability in primary energy, we need to focus on this list.
Coal will probably dominate the primary energy supply for many years, as oil and gas ramp down. But sooner or later, coal supply will become more of an issue worldwide, and prices will eventually rise. Furthermore, there are large parts of the world where coal is not so plentiful or accessible, and they will need to make use of one of the other energy sources. The national security constraints suggest that it would be very dangerous to have all these regions rely entirely on nuclear. Therefore, sustainability on a global basis will depend heavily on our ability to our ability to make earth-based solar or SSP affordable. If we can find a way to make earth-based solar or SSP cost as little as nuclear electricity in areas like the Middle East, the benefits to human security will be enormous. If we can make them cheap enough, there is even a hope of a major economic boon to the US as well.
In 2001, the Millennium Project of the United Nations system (http://millennium-project.org) asked policy makers and science policy makers all over the world: "What challenges can science pursue whose resolution would significantly improve the human condition?" The leading response was: "Commercial availability of a cheap, efficient, environmentally benign non-nuclear fission and non-fossil fuel means of generating base-load electricity, competitive in price with today's fossil fuels."
All of this leads up to the following question: how can we maximize the probability that earth solar and/or SSP will become cost-competitive with coal and nuclear? What are our chances of success in either or both alternative?
Maximizing Earth Solar and Allied Technologies.
For large-scale earth-based solar power, there are two well-known alternatives – solar farms based on solar thermal technology, and solar farms based on photovoltaic chips (PV). As discussed earlier, the best known way to generate solar thermal power is the Sandia design, using mirrors to generate intense heat, STM engines to convert heat to torque, and turbogenerators to convert torque to electricity. STM claims that the resulting electricity cost is much less than that of PV farms – but of course we need to continue to work on both streams of technology. A new successor company to STM, Lennart Johannson global associates, has worked with members of the Millennium Project to follow up these possibilities on a private sector basis. As noted at http://smalley.rice.edu, a small fraction of the earth’s deserts would be enough, in principle, to meet all the world’s energy needs, using ground-based solar power; the advanced SAIC+STM design can provide the lowest available costs for that purpose, particularly in developing nations (where the labor cost of assembling mirrors is far less than in the US.).
People who try to market earth solar systems, distributed generation and wind power generally agree that these technologies already make sense in many market segments, much larger than existing sales. They generally say that the major barriers to greater use of the technology are two-fold: (1) difficulty in getting hookups to the electric power grid and good payment for electricity they sell to the grid; (2) nation-wide zoning requirements which require all distributed generators to obtain zoning as major power producers, before they are allowed to sell any electricity at all to the grid. Professor Lester Lave of Carnegie-Mellon has done some interesting research on the latter problem.
The first problem is actually a reasonable market response to the needs of electric power grids managed by old control methods, which are not adaptive enough to fully capture the benefits of distributed generation entering the grid. Dynamic Stochastic OPF (discussed previously) is theoretically the optimal way to overcome these problems. The challenges in DSOPF are not in discovering new fundamental technology, but in building up software to implement new technology already discovered and teams of engineers capable of following through. New transmission hardware will also play a crucial role (as in the 2001 NSF-EPRI workshop discussed earlier), but electric power investments based on older control paradigms might actually delay the paradigm shift which is needed here. Dr. James Momoh of the ECS Division of NSF has for two years funded (joint with the Navy and the Social, Behavioral and Economics division of NSF) a special initiative called “EPNES,” which tries to foster the new types of cross-disciplinary partnerships needed to solve these kinds of problems – but for two years money has been sent back, because of the lack of really vigorous truly cross-disciplinary partnerships. The cultural problems are larger barriers than the objective technological difficulties. But we need to keep on working on these problems, ever more vigorously, building especially heavily on those groups which really are trying to move seriously in new directions.
With regard to zoning – it is my opinion that someone at a national level really should be able to change or bypass the relevant national zoning rules. Instead of requiring that all distributed generators (DG) must be zoned as full-fledged large-scale power plants, there should be a blanket exception for all DG which only use alcohol or renewable energy sources when generating electricity for sale to the grid. This would allow companies like Intel, in California, to afford to pay for DG as a backup to the gird, by amortizing the cost against generation they sell to the grid in normal times.
Solar thermal technology could also be enhanced and accelerated by the development of new markets and partnerships which further the STM component. For example, sources of biomass like wood and sugar cane will never be large enough to meet more tan a small percentage (less than 10 percent) of world needs. But it is a shame to waste half or more of their energy content, by converting them to ethanol or methanol fuel, as is very popular in large parts of the world today. By burning them to produce heat in high-efficiency furnaces, and converting that heat to electricity via STM and turbogenerators, one could arrive at an important new near-term source of electricity, particularly in countries heavily blessed with timber or sugar cane. Wood furnace technology has been developed very far in Sweden, and sugar cane technology in Brazil. This could also provide an alternative in those countries to the burning of natural gas to produce electricity, allowing that fuel to be better used in producing methanol for cars. All of this would only be a steppingstone to the use of solar thermal technology, but it could be very useful in facilitating a transition to solar thermal.
Maximizing Space Solar Power and Allied Technologies.
The average solar flux per square meter in geosynchronous orbit is at least an order of magnitude larger than the flux in the most promising deserts on the surface of the earth. Therefore, it would be irrational not to fully explore what the possibilities might be to exploit this enormous resource.
Circa 1978-79, NASA and DOE were funded to develop a reference design for an SSP system, and to evaluate it in depth. NASA projected a cost of electricity of 5.5 cents per kilowatt-hour at that time, but the DOE report was far more skeptical. Dr. Fred Koomanoff, a Division Director at DOE Basic Energy Sciences led the DOE evaluation. He also enlisted the help of several technical experts, including myself from EIA.
Several active lobby groups pushed very hard (and successfully) to discontinue SSP funding at that time. They cited the DOE evaluation as an argument for discontinuing research in that area. Many space advocates perceived the DOE group as enemies on space solar power and space in general. But all of this was a matter of gross distortion, motivated by the belief of many advocates that they have a duty to be “effective lawyers for the cause,” stretching the truth to win support for their side.
In actuality, neither Koomanoff nor I intended to take a position for or against SSP at that time. To the extent that SSP might be viable, we felt it was critical to identify and understand the critical obstacles as early as possible. No new technology benefits from having so much biased leadership that the key problems are addressed only after billions of dollars are wasted on overly simplistic blind alleys. Many major government investments have suffered from this kind of problem.
Several years later, NASA was funded to take a fresh look at SSP. Under the leadership of John Mankins, intensive studies were carried out which identified even more problems with the original reference design – and also sugggested possible solutions.
In 1990, NSF and NASA held a joint workshop on the possibilities for using computational intelligence to reduce the costs of building SSP systems. Inputs were obtained from many creative thinkers, such as Fred Koomanoff, Prof. Toshio Fukuda of Nagoya University (arguably one of the world’s two top experts in intelligent robotics, with ties to Honda), Rhett Whittaker of Carnegie-Mellon, and Criswell and Ignatiev (major champions of the use of extraterrestrial materials). This workshop, plus subsequent discussions on microwave power beaming, led to a new joint solicitation in March 2002, in which the Electric Power Research Institute (EPRI) also joined as a funding sponsor. By searching on JIETSSP at www.nsf.gov, one may easily locate the program announcement, which summarizes the major technical themes and provides web sources for extensive supporting literature.
Mankins and I served as joint co-chairs of the JIETSSP working group. NSF and NASA made equal contributions.
The announcement generated 99 proposals. After very intense and tough peer review, the panels recommended $21 million worth of research – but only $3 million was available. Thirteen proposals were awarded – but I subsequent months we learned that some of the highly recommended proposals we could not fund were of enormous importance, and I for one deeply hope we can make up for the neglect of much critical work in this area.
SSP is still a very high-risk area of technology (though not so risky as “the hydrogen economy,” in my view). We have good ideas of what needs to be done next, but we have to make guesses (as in wildcat drilling) and we need to be very adaptive in setting priorities and considering new ideas. But we need to remember that the challenge to policy-makers is to minimize the risk that the world does not have an affordable source of baseload solar power in time to prevent life-threatening problems. The risk that really matters is the risk that would be greatest if we did not explore both of the promising large-scale options for solar power. We have no guarantees of success – but if in the end we do not succeed, nothing else will guarantee our survival either. In the “review criteria” letter for this initiative, we asked the reviewers to consider the risk that we might lose something critical – and delay the market-competitiveness of SSP – if we did not fund any particular project.
In my personal opinion (this week), there are three types of technologies which have reasonably good hopes for delivering electricity at prices competitive with coal and with conventional nuclear. Two of them could theoretically be cost-competitive as soon as ten years from now, if we were lucky and if political difficulties did not get in the way. The three are: (1) a “conventional” design augmented by nanotechnology; (2) a novel solar-nuclear design, spelled out for the first time (other than emails) in this paper; (3) designs based on extraterrestrial materials.
By “conventional” designs, I mean some of the more recent kinds of designs evaluated in previous work on life-cycle costing funded by NASA. In the Technical Interchange Meeting of September 2002 held at the Ohio Aerospace Institute, it was stated that those designs still show costs of about 17 cents per kilowatt hour, assuming earth-to-orbit costs of only $200/pound and aggressive but realistic development of established technologies in key enabling areas. These designs involve the usual idea of vast arrays of solar cells (typically with intense concentrating mirrors, as in the work of Entech), followed by wires
and transformers carrying electricity to a system beaming microwave power to earth. Of course, 17 cents per kilowatt hour is not competitive, and that is why breakthrough-oriented research is essential.
Some critics have questioned whether even this reference analysis is right. For example, how sure are we that microwave power beaming can work as well as needed? In actuality, the NSF team which generated this solicitation in the first place started out as an even there-way partnership of three people – myself, Dr. James Mink, and Dr, James Momoh. Dr. Mink had been editor-in-chief for many years of the main IEEE journal on microwaves, and the microwave engineering community make a major contribution to making this activity possible. They believed that new research is essential – but that the chances of success look good enough to warrant the effort. Some serious critics worry that power beaming might interfere with wireless communications; however, one of the funded PIs, Prof. Frank Little, predicts that he will soon have hard empirical demonstration that his designs for avoiding such problems really do work. Many other concerns regarding human health and the ecology have been studied very carefully already; though further studies are being funded, the claims of many anti-SSP lobbyist appear very grossly misleading at this point. In my opinion.
But how could we get below 17 cents per kilowatt hour, when even that assumes transportation costs far below what is in sight at NASA?
One of the proposals to JIETSSP (for which the PI has granted me permission to reveal some private information) involved an extension of recent exciting vehicle design work funded by the Air Force and by NSF, in other contexts. Ramon Chase of ANSER, Inc., proposed a breakthrough design for reusable rocket-plane transportation, exploiting little-known off-the-shelf technology from a combination of Lockheed-Martin, Boeing proper and from the former McDonnell-Douglas. Peer review questioned whether NASA or NSF would have the ability to manage the vehicle development work required to follow on such a design – but it also supported the claim that this particular new design concept is highly unique and highly credible. A target of $200 pound for the initial vehicle, to operate within a decade, seems highly defensible (unlike the case with earlier designs who have made similar claims without a comparable level of detailed engineering cost support). The design also lends itself a better than average subsequent learning curve, and a number of dual-use benefits. In my personal opinion, it would be a criminal loss to the world if this new and exciting option is not fully followed up on. Fortunately, there are some highly competent and well-motivated experts in the Department of Defense who understand what is at stake, and have a serious hope of navigating the very, very difficult political shoals and vested interests. But the politics is extremely complex, and it is hard to predict how it will come out in the end. I deeply regret that random events kept us from funding the final design study in 2002, and I hope that a way will be found before too long.
But even that would not be enough for the conventional design to be competitive in time for the first launch. The problem is that the present designs require a lot of weight to be launched – about half of it for the solar cell part, and half of it for the wires and transformers. However, at recent workshop on nanotechnology at the Woodrow Wilson Center in Washington D.C., breakthroughs were presented both in solar cell design and in wires and transformers, using nanomaterials. Dr. Richard Smalley – who received the Nobel Prize for discovering the carbon nanotube –stated that the weight of wires and magnets (including transformers) could be reduced for sure by a factor of 6, using such materials. Such wires need not meet the very specialized electrical standards required in nanoelectronics, for which the costs are relatively high; most likely, the more low cost kinds of materials discussed by Varadan of Penn State may be relevant. At that same workshop, physical samples were distributed of new types of bendable, light-weight nanomaterial-based solar cells. Weight reductions of a factor of five or more could possibly lower costs from 17 cents per kilowatt hour to something more like one-fifth of that; even with allowances for
other, smaller cost factors, this looks as if it provides real hope for becoming competitive with today’s base-load electricity.
At the workshop, no one could say whether the breakthrough solar cells could survive the harsh environment of outer space. However, it seems as if the key titanium-based nanoparticles can be painted onto almost any clear plastic. There are plenty of very light clear plastic film materials which are space-rated (and part of the previous NASA SSP program).
So that is one option.
Another option which I thought of a few months ago, and discussed so far only by email, is a hybrid of solar and nuclear technology. This is a riskier approach – but if it should happen to work, the potential near-term cost reduction could be startling.
Hydrids with nuclear technology tend to generate automatic irrational visceral reactions from those who fear all things nuclear. But it is important to remember that the national security and environmental problems with conventional nuclear energy on earth are almost entirely the result of the neutrons which fly out of those systems on earth. There are alternatives.
Nuclear fission and conventional deuterium-tritium fusion all produce huge amounts of neutrons. There is no prospect at present of magnetic bottle (“tokomak”) fusion being able to use different fuels like pure deuterium or deuterium with helium-3. However, John Perkins of Lawrence Livermore Laboratories has developed a new, breakthrough design for fuel pellets to be used with “inertial” or laser-induced fusion.
This has potential advantages on earth – but still some serous limitations. The D-D reaction still spits out about one-third of its energy as neutrons, which leads to all the usual problems on earth. The D-He3 reaction is hard to do in a purely earth-based operation, since the nearest significant sources of He3 are on the moon or (maybe, so far as I know) the asteroids. The high-powered lasers required for laser-induced fusion are a huge cost problem on earth, because of the need to tie up giant power sources to supply the electricity which drives them, and the massive construction reminiscent of the old supercollider proposal.
But my idea: why not use Perkins’ kind of design in space? Why not use lightweight mirrors and light-to-light lasers floating in orbit, in place of the giant construction project on earth? Why not let the one-third neutrons just float away into space (where they turn into protons in 12-15 minutes on average anyway)? Instead of having a big nuclear reaction chamber, why not simply post a couple of big magnets near the place where the light hits the pellets and the energetic protons come out? (In other words, why not use a lightweight MHD system to extract the electricity from the current of protons?) A quick cost estimate, based on $200/pound to orbit and $200/pound from low orbit to geosynchronous orbit, suggests that the cost of carrying these pellets to orbit would add only 0.1 cents per kilowatt hour to the cost of the electricity generated. The cost of the deuterium as such would be negligible; “heavy water,” deuterium dioxide, is a major fraction of ordinary seawater.
The biggest challenge here would be the design of the laser or lasers, suitable for generating the kinds of pulses Perkins requires. I have discussed this at length with Leo DiDomenico and Jonathan Dowling of the Jet Propulsion Laboratory (JPL). (Dowling is a unique world-renowned expert in experimental quantum optics and quantum information science. DiDomenico works with him on lasers and other topics.) They both believe that there is very real hope here. More precisely, they are now working out the details of a new laser design which might be enough to do the job. They describe their present status as follows. They are working on single-strand High Power Fiber Laser (HPFL) technology. They are working on bundling the HPFL strands to create a coherent large-aperture high average-power system, and on direct solar pumping of the bundle and the strands. They are using Photonic Band Gap techniques to create large mode-area fiber lasers (already known in the literature). They are also using inflatable mirror systems to create the etalon. They are also continuing to follow up on our discussions of larger energy applications, like the use of lasers in fuel creation, fusion and SSP. They are also looking at new approaches to earth-to-orbit transportation. (In fact, we have funded Ray Chase and Princeton to explore radical air-breathing approaches to earth-to-orbit transportation. The “near term” vehicle design discussed above is critical as a way to consolidate technology needed as a steppingstone to such more advanced possibilities.)
There are no fundamental reasons why his new option could not be implemented – especially given the unique environment in space where large structures held together by tension are far easier to assemble than on earth. (JIETSSP is also funding four projects in robotics assembly. Greg Baiden of Canada and Penguin ASI has demonstrated working “teleautonomous” robotic mining systems which prove that this kind of complex project probably can be done with today’s robotics technology – but additional work is needed to nail down the options and optimize performance.) In discussions between myself and JPL – the early cost guesstimates for electricity look extremely promising. Cooperation and expanded efforts with Lawrence Livermore would be essential to bringing this option to fruition.
Two further issues are important to evaluating this option.
First, the JPL laser effort is central – but there is good reason to believe that other laser options should be explored as well. This paper is not the right place to elaborate on the technical issues of laser design, but some of us do need to think about those issues. Experience so far suggests that we need a combination of focused efforts like an expanded effort at JPL, in parallel with broader efforts widely open to universities and small businesses (as in JIETSSP) to dredge for new ideas and creative people.
Second, the cost of electricity beamed from space in this option would be mainly a matter of the capital cost in building the laser(s). Previous work (e.g. some collaboration between myself and Prof. Richard Fork of the University of Alabama, reported at the Technical Interchange Meeting previously discussed) suggests that light-to-light lasers by themselves provide an interesting option for SSP. No one knows as yet whether they would be four times as expensive or one-fourth as expensive as today’s conventional SSP designs, or more or less, but they generally appear comparable. However, it is well known that a laser fusion system can augment the power output by a factor of 100 or more. When 100 times as much power is produced at almost the same capital cost, the cost per kilowatt hour is reduced by a factor of 100. If it were not for Murphy’s Law, one might seriously hope for baseload electricity at less than one cent per kilowatt hour here. Murphy’s Law is very real in engineering – but there still is serious hope here of providing electricity at costs significantly less than what we all are paying today. This would not only be an economic boon, but also a great stimulus to the kind of transition discussed in the previous section.
Given that the cost of lifting material from earth orbit has been the main cost driver in conventional designs, it also makes sense to pay close attention to options which lift up most of the material from other places. These were not included in the scope of JIETSSP, mainly because of insufficient funds to do justice to the topic. However, Ignatiev’s work on making solar cells in situ on the moon is extremely serious; Ignatiev has been a long-time grantee of NSF, very knowledgeable in the manufacture of all such solid state devices. This is a long-term back-up option, but the exploration of such options might have other important benefits even if the other paths to SSP should work out sooner.
Summary and Conclusions
This paper has proposed a vision of global energy sustainability, which may well be necessary (though not sufficient) to long-term survival of the world economy. It requires that we focus our efforts far more directly and effectively on four key variables: affordable, sustainable car fuel; affordable, sustainable primary energy; CO2; and global nuclear security.
Despite the huge amount of talk and money and legal discussion on global sustainability, our chances of success actually seem to boil down to an array of relatively less expensive critical issues – few of which are receiving adequate attention. In order to maximize our chances of survival, we need to
wake up and cooperate more effectively in addressing the concrete opportunities and challenges which face us.
Dr. Paul J. Werbos.
Hoja de Vida.
· The views herein are certainly those of the author, not those of the US government or any agency thereof. In fact, there has been no agency review or consensus process at work here at all; it is strictly a First Amendment exercise, the kind of exercise which is essential to effective information processing in an information economy.