March 24, 2003
Is Hydrogen The Energy Of The Future?

The April 2003 issue of Wired has an article written by Peter Schwartz and Doug Randall advocating an accelerated conversion to a hydrogen economy. After discussing the problems inherent to storing hydrogen in gaseous and liquid forms they argue that solid materials as hydrogen sponges will be the best long term solution.

In the long run, the most promising approach is to fill the tank with a solid material that soaks up hydrogen like a sponge at fill-up and releases it during drive time. Currently, the options include lithium hydride, sodium borohydride, and an emerging class of ultraporous nanotech materials. Unlike gaseous hydrogen, these substances can pack a lot of power into a small space of arbitrary shape. And unlike liquid hydrogen, they can be kept at room temperature. On the other hand, energy is required to infuse the solid medium with hydrogen, and in some cases very high temperatures are required to get the fuel back out, exacting a huge toll in efficiency. Also, filling the tank can take far more time than pumping gasoline. Government money could bridge the gap between today's experiments and a viable solution.

But will the problems involved in solid hydrogen storage be any more tractable and yield to any better solution than the problems with gaseous or liquid storage? Will the solid material needed to store the hydrogen weigh so much as to make it weigh as much as a battery which would contain the same amount of energy? The authors provide no indication as to why their preferred approach will turn out to be so advantageous.

The bigger problem with the article is that it does not explain why the use of hydrogen will allow us to reduce and eventually eliminate the use of fossil fuels. Hydrogen is not a source of energy. It would be more accurate to say that hydrogen is a way to store, transport, and use energy. Therefore it competes with other forms of stored energy. In cars and other vehicles hydrogen could be burned in fuel cells. But energy is needed to produce the hydrogen in the first place. To be a better automotive fuel hydrogen would somehow have to reduce the total usage of fossil fuels and do that better than other approaches that could be pursued.

Fossil fuels are a major source of energy today. Fossil fuels could be converted to hydrogen. But hydrogen advocates have not made a clear case for why hydrogen as an intermediate storage and end use form of energy is a more efficient way to use fossil fuels. There are too many unsolved problems and questions. Again, hydrogen does not really compete against other types of originating fuels. Rather, it relies on other types of originating fuels because it has to be produced using these other fuels.

If hydrogen is produced from electricity then the electricity must first be generated. But most electricity is generated by burning coal or natural gas. Hydro and nuclear also produce small fractions of the total electric supply. We've pretty much harnessed the available hydroelectric sources and hydroelectric is a pretty small fraction of total electric generation. The other big current alternative is nuclear energy. But for electricity generation nuclear power costs more than burning fossil fuels. There is no big economic incentive on a global scale to drive the building of massive numbers of nuclear power stations to cause a conversion to a nuclear-hydrogen economy. Also, widespread use of nuclear power on a global scale would so increase the availability of enriched uranium and plutonium that it would cause unacceptable risks of nuclear and radiological weapons proliferation.

The economic case for the use of nuclear power looks even worse than current fossil fuel prices suggest. The marginal cost of oil production (in some fields it is about $3/barrel) in the Middle East is much lower than current oil prices. Therefore nuclear power can not displace the use of Middle Eastern fossil fuels unless nuclear power becomes much cheaper than it is now.

Fossil fuels could be used to generate hydrogen. Would this be a more efficient way to use fossil fuels for transportation purposes? Keep in mind that each step in the use of hydrogen would produce an energy loss. The efficiency of the energy conversion of fossil fuels to hydrogen would be less than 100%. The hydrogen could then be piped (or driven) to what are now gasoline stations. If liquid hydrogen was used in cars then the hydrogen would have to be cooled first to liquid form. To keep it cool would require a great deal of insulation and probably additional cooling on-going. Therefore a car just sitting in a parking lot would consume energy at some low rate. As the Wired article points out, even a solid storage method may require energy usage in order to get the hydrogen into the solid and to get it back out again. Meanwhile, there are an assortment of ways to make the old internal combustion vehicle more fuel efficient. Therefore hydrogen is not just competing against today's internal combustion engine transportation systems. It is also competing against tomorrow's.

Hydrogen would most likely propel vehicles by being burned in a fuel cell. In theory fuel cells are a more efficient means of converting a liquid or gaseous fuel to mechanical power than the internal combustion engine. But hydrogen is not the only energy form that can be burned in fuel cells. There are fuel cell designs that will burn methane gas for instance. In fact, due to the greater efficiency of fuel cells for the conversion of fosil fuels to electricity fuel cells will become widely used for electric power generation from fossil fuels before they become used in transportation.

Is hydrogen the only viable candidate as an energy storage form to replace gasoline and diesel fuel in vehicles? In a word, no. Lead acid batteries have an energy storage density of 35 Watt Hours per kilogram. This leads to electric cars that weigh too much and have too short a range between recharges. MIT professor Donald R. Sadoway believes lithium polymer batteries can be developed that will have over an order of magnitude greater energy density than lead acid batteries.

Niels Bohr, the Danish physicist and Nobel Laureate, once cautioned that prediction is always dangerous, especially when it is about the future. With this disclaimer, then, we speculate on what is in store for rechargeable lithium batteries. In the near term, expect the push for all-solid- state, flexible, thin-film batteries to continue. This is driven by the desire to maximize the electrode–electrolyte inter-facial area while minimizing diffusion distances within the electrodes themselves, in order to combine high capacity with high rate capability. Recent results from our laboratory indicate that in a multi-layer configuration comprising an anode of metallic lithium, a solid polymer electrolyte, and a cathode of dense, thin-film vanadium oxide, it is possible to construct a battery with projected values of specific energy exceeding 400 Wh/kg (700 Wh/l) and specific power exceeding 600 W/kg (1000 W/l).10,11 Another trend is distributed power sources as opposed to a single central power supply. This allows for miniaturization (e.g., the microbattery). Expect also the integration of energy generation with energy storage, for example, a multilayer laminate comprising a photo-voltaic charger and a rechargeable battery. Ultimately, if scientific discoveries prove to be scalable and cost-effective, we should witness the large-scale adoption of electric vehicles.

When the cost of photovoltaics is lowered far enough to compete with fossil fuels then a combination of photovoltaics and lithium polymer batteries may well be the combination of technologies that will lead to the phase-out of the use of fossil fuels as vehicle power sources.

The article co-authored by Donald Sadoway and Anne Mayes is from the August 2002 issue of MRS Bulletin dedicated to lithium batteries.

Share |      Randall Parker, 2003 March 24 02:45 AM  Energy Tech


Comments
Matthew Hiatt said at March 24, 2003 11:02 PM:

You're not quite right on your figures for nuclear power costs. It only costs about $.02 per kWh for nuclear power vs. $.03-$.04 for natural gas. Oil is in between the two. This is why everyone who supports a hydrogen economy (and actually thinks about the problem) recognizes that a surplus amount of energy is needed in either the form of nuclear or one of the renewable fuels to make it all go.

Randall Parker said at March 24, 2003 11:50 PM:

Matthew, I've seen reports that stated higher costs for nuclear power costs and lower figures for combined cycle gas turbine (CCGT) costs. Obviously the natural gas electricity cost depends on the long term price trend of natural gas and price trends are hard to predict. But there's also debate on what new nuclear plants would end up costing and how much cost should be assumed for decommissioning, waste disposal, and other factors (e.g. security).

For details of a cross-country comparison done in December 2002 see The Economics of Nuclear Power. That page puts nuclear costs as higher than coal or natural gas in the United States. But of course long term natural gas costs are hard to predict.

I think your low $0.02 per kWh may be for existing plants whose capital costs have already been depreciated. See this article which estimates a cost of 1.82 cents per KWh for existing nuclear plants but 4.5 cents for new plants.

Paul Stevens said at March 28, 2003 12:32 PM:

When you consider the cost of nuclear or competing coal or natural gas sorces of electricity you should probably couunt on some form of "carbon tax" in the future. This has a significant impact on natural gas production and even more on coal.

In addition, new technologies available for future nuclear sites result in lower capital costs, one of the most significant considerations in nuclear plants.

An additional consideration is the ability of the existing infrastructure to deliver the volumes of gas required. Would new pipelines be needed? I have no idea, but pipelines would not be cheap.

Kari Appa said at December 14, 2003 6:28 AM:

Ill concieved and Wrong arguement. The future trend would be to use the renewable sources of energy (wind and solar) to produce hydrogen, which would have been let go unharnessed. Every household roof top may have either solar panel and/or wind turbine to produce and store energy in the form of hydrogen which one could in a car to drive around the city without polluting the environment.
I support the hydrogen movement.

Edward McClendon said at June 11, 2004 6:08 AM:

Hydrogen will become the dominant source of the world's energy because the world can not continue using carbon-based fuels. CO2 build-up and global warming are real problems, as is the declining amount of easily extracted oil. And the geo-politics of oil rests on warfare.
Solar cell technology is advanced enough to warrant a "Manhattan Project", now. Massive amounts of federally owned land could be covered with solar cells within a few years. The energy would be cheap enough, and plentiful enough, to split water for hyrogen fuel cells.
There would be no residual problem with the massive amounts of oxygen released in the splitting of the water molecule. The fuel cell would recombine it with the expended H2. (The Earth was not able to sustain life in its early formation as the amount of O2 was inhibitory. Until this corrosive molecule was tied up in water, through immense amounts of oxidation of material, the planet was near sterile). The world will not end this century dependent on oil, natural gas, or coal. And there will be monstrous changes in the roles that the OPEC nations now play. As well as the immense recapitalization of the industries engaged in the production of carbon based energy sources, and the machines that use these sources. We need this technology, literally, to save this planet from having sterile seas, from having the oceans rise 10 feet or more, and from destroying the quality of air that we breathe. Massive amounts of energy already are needed to begin the processes for sequestering the monstrous surplus CO2 that the industrial age has built up in just 100 plus years.

Terry Rudersdorfer said at March 14, 2005 2:54 PM:

It amazes me that people are still debating the issue of what we should be doing ... Fossil fuels (coal,Oil,Natural Gas) are all finite ... it will be all gone before certain groups let go of this 20th Century vision of the world. Nuclear, Lithium, or any other exotic chemical based Generation/storage just perpetuates the myth that we can continue to rape the finite resources of the planet. Yes, Hydrogen has issues that need to be addressed ... Europe is moving full tilt on developing a Hydrogen based economy as we speak ... we should be too!!!
Hydrogen is reusable ... it requires no additives ... has only one side product (Pure Water!) ... it can be produced on site eliminating distribution costs ... a combination of Geothermal, Solar, Tidal, and or Wind plants could be used to generate all of the hydrogen required to fuel our transportation needs without disturbing our existing power grids. Mercedes has just produced a hybrid vehicle that runs on both GAS and LIQUID Hydrogen ... they have designed a liquid hydrogen fuel tank which tests have shouwn is much safer then our current gas tanks. The bottom line is that Hydrogen combined with other renewable energy sources is the only way I believe mankind can survive into the future. If we don't start doing something NOW, I can certainly envision a world fighting over whatever energy resources are left ... I am not sure the world could survive another world war.

Sione Vatu said at September 7, 2005 2:32 PM:

Quoting: "light-driven chemical process that would fix carbon out of atmospheric carbon dioxide to make hydrocarbon fuels".

This sounds interesting. If we can do something like that we can avoid the need for hydrogen storage and distribution infrastructure(a Gigadollar problem). Automobiles don't have to become rolling laboratories (with all the cost and relaibility issues that leads to). It also avoids the need to produce huge arrays of photovoltaic cells and erect them (there are serious environmental issues with these things and the costs are prohibitive- do the math, they never break even).

A light-driven chemical process is what plants use, so there is precedence in nature; always a good pointer. And chemical processing plants are known technology... All that is required is to know what the recipe is to be. Best part is that this could be phased in without needing to undertake yet more reich-building MEGAPROJECTS (America has had enough of these already). Chemical plants can be whatever size the customer demands and installed at the rate the market will bear.

Who is researching this field? What processes are on offer?

G. Smith said at August 19, 2006 5:38 PM:

Hydrogen......You need energy to produce it, you need energy to compress it (to about 10,000 psi) , then you lose energy (waste it) converting it back into (guess what) electricity. It takes more energy to produce and store hydrogen than you get out of it. It would be better to put that electricity into a lithium phosphate or similar advanced battery that has a high kw per weight ratio. With batteries the energy goes through much less conversions, hence it is more efficient, hence less power plants (nukes, wind, solar, etc) needed. How many hydrogen cars are for sale? How many hybrid cars are for sale? We are beginning to take steps towards the transition to electric cars. Welcome to the 21st century.

S.V.Karthikrajaa said at November 19, 2006 7:59 AM:

dear sir,
i m karthikrajaa from chennai,INDIA & i m doing diploma second year in automobile. since i want to do a project for my final semester so i selected my project as a covertion of petrol fuel engine to hydrogen fuel engine but i can't able to collect details about that. so can ge me some detail of hydrogen fuel engige.i hope that you will reply soon
thankingyou,

S.V.Karthikrajaa

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