Up to: Sustainabilty


Q. Isn't the world running out of energy.

A. No. Nuclear and solar energy are each adequate for the next billion years. That's right; billion not just million or thousand. Bernard Cohen published the facts about that.

This page assumes the law of conservation of energy. If you don't understand that, look at law of conservation of energy. Here's how you can tell if you don't understand. Several times I have received in email the following idea for powering cars with hydrogen from water. Run the car on hydrogen obtained by splitting water by electrolysis using the car's generator to get the electricity. If you can't quickly explain why that idea can't work, you need to follow the above link.

Q. Are the campaigns to save energy in every possible way a good idea?

A. No. There is plenty of energy to be had. In the short run, Europe, Japan and the U.S. can continue buying oil on the world market, and the U.S. can drill more oil and gas wells. The recent increase in oil prices led to doubling the number of oil drilling rigs. In the medium term (from ten years or five in an emergency) and long term, nuclear energy can supply all the world can want.

Q. What about fuel for cars?

A. The world will run out of petroleum from oil wells. Maybe in 20 years, but more likely in 50 to 100 years. Here are the American Petroleum Institute's estimates of oil supply.

On 2004 March 10, the Wall Street Journal, had an article about estimates of oil reserves. The gist of the article is that estimates are very uncertain, especially of reserves from countries that don't require accounts from oil extractors and publish the results. The US Geological Survey (USGS) is rather optimistic. Some other analysts think the USGS is too optimistic.

If we take the paranoid or merely cynical view, we might suppose that a company would be inclined to exaggerate its own reserves to keep its stock price up and underestimate world reserves in order to keep the oil price up. Maybe governments with oil reserves would have similar motivations. I have no information about whether companies and governments actually do that.

Note on consensus: There are two kinds of consensus.

Type 1. People independently look at a problem and discover they agree. This is worth something, although they may be all making the same error.

Type 2. People are just copying each other. This consensus is worth no more than the opinion of the original (probably dead by now) person they are all copying.

I worry that the present consensus on oil reserves is partly of type 2. This is suggested by the WSJ article.

If Thomas Gold is right about deep hydrocarbons, not produced by life, and if they can be mined economically, then petroleum will last very much longer.

Also if natural gas from methane hydrates proves economic to extract, we are in good shape for a long time. There is more gas in methane hydrates than there was in natural gas fields. However, experiments at extracting gas from methane hydrates are just beginning in 2004.

Hydrogen, produced from water by nuclear energy, is an adequate long term substitute for oil and natural gas. Bernard Cohen has shown that getting uranium from seawater will be an adequate source for billions of years. Energy costs might go up, but humanity could still afford them. However, oil and natural gas and political inertia may be still too cheap to justify major investment in hydrogen now.

Q. What about global warming?

A. The "greenhouse effect" that worries people is global warming from increased human emissions of carbon dioxide into the atmosphere. It is not yet known how much warming will be caused if we continue and increase our use of fuels containing carbon. It is also unknown whether this would be harmful. Our energy future is certainly affected by whether the global warming turns out to require substantial reductions in burning. Here is a beautifully presented Global Warming Update written in 1994 and updated in 1998. The main collector of dissents from global warming is the Science and Environmental Policy Project.

Q. What if the greenhouse effect is *not* important?

A. The world's oil reserves are limited to 50 or 100 years, maybe less. The world's oil resources are much larger, 1,000 years is possible though unlikely.

Q. What's the difference between reserves and resources.

A. Reserves include what is extractable at more or less present costs. If you own land with oil on it, reserves are what you can hope to sell at a profit at present prices.

Resources also include what can be extracted and sold at some price buyers will be able to afford, but don't have to pay at present, because others are selling it for less.

Q. What are our oil reserves?

A. These include only crude oil that can be pumped economically. The U.S. has used up most of its reserves and now imports more than half of its oil. They aren't all gone, and investors keep between 700 and 1,000 oil rigs drilling for more. The Arabian peninsula has much larger reserves and is presently selling it without political conditions.

The U.S. Geological Survey has recently completed a project to get a new estimate of oil and gas reserves and resources in the U.S. They turned out to be much larger than was anticipated.

There are controversies about the size of reserves. C. J. Campbell, a respected consultant has a book The Coming Oil Crisis arguing that cheap oil will soon be in short supply. The general opinion seems to be that Campbell underestimates the amount of cheap oil to be found. Philip Abelson has an editorial in Science for 1997 April 25 describing new methods of exploration and production that should delay oil becoming much more expensive. The Oil & Gas Journal-online is the major trade magazine. It charges for a subscription, but some information is available free.

The American Petroleum Institute has a web page giving facts about supplies, etc. and with position statements by various people in the petroleum industry. Their position is that the world is not close to running out of oil. Oil Supplies -- Are We Really Running Out of Oil? gives what seems to be the industry position in this matter. The article gives a 95 percent chance that world conventional oil supplies will last 63 years and a 5 percent chance that they will last 95 years. Non-conventional supplies (i.e. resources) will last much longer. Longer articles are Oil Supplies in pdf format with an Executive Summary as an html file.

Note, 2003 Oct 30: EIA: US PROVED OIL AND GAS RESERVES INCREASE FOR 4TH CONSECUTIVE YEAR US proved reserves of natural gas and crude oil have increased for the fourth consecutive year, the US Energy Information Administration reported. http://ogj.pennnet.com/articles/web_article_display.cfm?ARTICLE_ID=190982

Q. What are our oil resources?

A. There are several kinds.

  1. Oil from fields not economically extractable at present prices.

  2. Oil shale. This is minable in Colorado and amounts to more than the Saudi reserves. Some years ago it was estimated as profitable at $35 per barrel. Oil cost just under $20 per barrel now when the first draft of this article was written in 1995. Now (1999 March) it is $12 per barrel. Now (2000 December) it is $28 per barrel. Chevron developed the shale process in the 1970s, but decided it wasn't profitable then. 2002 note: Shell is doing exploratory work in colorado on new processes for getting oil from shale economically.

  3. Tar sands. This is a very thick oil, and there is lots of it in Canada and Mexico. Some of it is extracted in Canada, but an increase in price was thought to be needed to make it economical. Now it is sufficiently economical even at $12 per barrel that new plants are being built.

    1997 January note: There is more than talk about Canadian tar sands oil production expanding. Present costs are now at $12.00 per barrel and it hoped that they will go down to $6.00 per barrel, way below present oil prices that fluctuate around $20.00 per barrel. Here's an enthusiastic report from Alberta Magazine. Large amounts of money are being invested - many billions. 2002 August note: Several hundred thousand barrels of oil per day are being extracted, and large scale investments continue.

  4. Oil from coal. The Germans used it in WWII, and the South Africans developed it for use in case of an oil embargo that didn't materialize. The U.S. has 800 years reserves of coal, and China has much more than the U.S.

    2004 September note: The present high price of oil, $40 per barrel, has revived interest in oil from coal. According to this article, China has ordered some large Sasol plants.

Q. Won't the higher prices of using the resources damage the economy.

A. Some but not much. Most other countries impose very high taxes on gasoline and other petroleum products, and it doesn't seem to damage their economies a lot. They aren't as prosperous as the U.S. though, so maybe there are some bad effects. Energy takes up about 8 percent of the U.S. GDP, so even doubling energy costs wouldn't seriously damage the economy. Quadrupling energy costs would be pretty bad.

Q. Should we go all out to economize the use of oil to make it last longer?

A. Probably not. Too many regulations are likely to be more harmful than letting the prices rise as the reserves get scarcer and as demand from the developing world grows. 2002 August: In saying this I'm disagreeing with political opinions including those dominating the scientific community and the Government financed energy studies community.

Q. Why is the importance of the greenhouse effect still uncertain?

Q. What if the greenhouse effect *is* seriously damaging and the world has to limit combustion?

A. Then we have to go to nuclear and/or solar energy? Both generate electricity and must be adapted for applications that are presently non-electric.

Q. What is the difference between nuclear and solar energy?

A. Nuclear energy is enormously cheaper, already in large scale use for generating electricity, and is better developed. It can be used anywhere in the world. Solar energy has been politically favored in the US and other developed countries, but it still can't compete even with substantial subsidy.

Q. Is nuclear energy safe.

A. Some people oppose it fiercely. Their arguments are discussed elsewhere in the detailed FAQ on nuclear energy . Nothing is perfectly safe, but nuclear energy is safe enough to rely on. In particular, it is safer than the sources of energy upon which we are accustomed to rely.

Solar energy is a resource rather than a reserve in most places and for general purpose large scale use. It requires large scale energy storage - and very long distance energy transmission facilities if it is to be used in the winter in northern countries. All this can be done but is expensive. Of course, solar energy has many limited uses already.

Both nuclear and solar energy generate electricity, and making them the dominant sources of energy would require using electricity for many purposes now supplied by oil and natural gas. (With both nuclear and solar, there is some prospect of using them directly to produce hydrogen without going through electricity as an intermediate. These processes would make the hydrogen moderately cheaper).

Q. What are the major uses of energy and what does their adaptation to electricity as a primary supplier entail.

A. Here are the main categories.

  1. Present electricity uses. In the main these will get cheaper. Nuclear energy is still near the beginning of its learning curve. If solar energy is required, e.g. for ideological reasons, electricity will get more expensive, at least for a while, but we will still be able to afford all the present major applications.
  2. Space heating. Natural gas and oil are the main sources in the U.S. The natural gas will last a long time, and it generates somewhat less carbon dioxide than oil or coal when burned. Maybe the greenhouse effect will even zap natural gas. Some other countries rely on coal. The biggest coal user is China (already a little more than the U.S.), and the prospects are that Chinese coal use will increase greatly.

    Electricity is used in the U.S. for space heating where electricity is cheap. It is still mainly resistance heating rather than the more efficient but more costly heat pumps. If it has to be used in the cold parts of the U.S., heating costs may go up. Maybe they won't, however. Economies in electric generation, improved building insulation and the use of heat pumps may keep the costs down. Here is information about the 1993 costs of electricity.

  3. Automobiles and trucks. There are many possibilities but none are immediately attractive.

    1. Good batteries. The big win would be batteries that can store somewhere near the energy per kilogram that gasoline stores. Then electric cars would be as good as gasoline powered cars in every way. A lot of effort has gone into batteries and success has been elusive. They may win yet. 2000 note: It is increasingly doubtful that good batteries can be had. The California Air Resources Board passed regulations demanding battery powered cars. They just (2000 December) backed down again on their demand that 28,000 electric cars be sold in 2003. The electric cars cost $20,000 more than gasoline powered cars and have to be recharged every 50 to 100 miles.

      [2003 April 9: GM just announced the end of its EV-1 electric car program. Of the more than 1,000 built by GM and leased in California, about 375 are still on the road. GM will take them all back when their leases expire. The program cost GM about $1 billion. The whole electric car program was a triumph of appeasement of ideology over engineering knowledge. The cars were unsuccessful except for hobbyists for exactly the reasons that were known before GM built them.]
    2. Not so good batteries. My opinion is that even if lead acid batteries have to be used American mobility will still be essentially preserved. The batteries would be the property of battery exchange companies. A car would enter a lane like a toll booth every 50 miles. Radio communication between the car's computer and the exchange station would establish the requirements. An automatic machine would open the battery compartment and replace the batteries which would be recharged in the exchange facility. The process would take 15 seconds to slow down, 15 seconds to exchange the batteries and 15 seconds to speed up again. This 45 seconds would have to be spent every 50 miles or so. Doubtless there would be some inconveniences, but the essential features of the mass use of automobiles would be preserved. Here are the details of the proposal.

      There may be better schemes.

    3. Hydrogen. Hydrogen has many advantages as a way of storing the energy. It is made by splitting water using electricity. (There are schemes for using nuclear reactors to split water directly, and if they work and are adopted hydrogen will be somewhat cheaper than if obtained by electrolysis.) The only way of storing hydrogen that meets the energy density requirements of cars is as a liquid. Liquid hydrogen is bulky and has some safety problems, but these don't seem to be any worse than those presented by gasoline. Here's more on hydrogen. BMW has built prototype cars, but as long as gasoline remains cheap they won't be produced in large quantity.

      Here's an article by BMW engineers. Oops, the link doesn't work directly as I have copied it, but the article and others can be found by Googling bmw+hydrogen.

  4. Airplanes. If we have to get rid of other uses of hydrocarbons, we can probably afford to keep them for airplanes even under rather severe greenhouse assumptions. Airplanes are extremely sensitive to the weight and bulk of their energy storage. A 3,000 pound car typically carries 90 pounds of gasoline, whereas a long range airplane has most of its mass as fuel when it takes off. Maybe liquid hydrogen would work for airplanes, but its bulk would increase drag and therefore reduce range. Some experts think its reduced mass compared to hydrocarbon fuel would more than make up for its increased bulk. I'd post more information on this question if someone would supply it. Even better, I'd link to other people's urls on the subject.

Q. What about air pollution from combustion?

A. CO2 is the only potentially serious problem. All the other combustion uses have been or can be cleaned up enough for practical purposes. There are some ideological problems that will be discussed in the page about ideology.

Q. What about increased use of rail?

A. This is feasible but can't preserve present levels of mobility. Individual mobility is much valued, and no amount of propaganda has succeeded in making people forego it. As fast as countries become prosperous, their citizens buy cars even when their "wise men" oppose it.

Q. What are the current costs of various sources of electricity.

A. Here is a subsidiary page on current costs of some sources of electricity.

Q. What about geothermal energy?

A. The temperature of the earth increases with depth. In some places there is hot rock close to the surface. In the Geysers area of Northern California, the Pacific Gas and Electric Company, has generated electricity from hot rock since the 1920s. Geothermal energy has also been generated in a suitable place in Italy.

After the first "energy crisis" in 1973, geothermal energy was one of the new sources tried out. Not much has come of it so far. The Idaho National Energy Laboratory has a research program on geothermal energy, apparently theory only. There is a Geothermal Education Association that promotes geothermal energy. Googling geothermal energy didn't elicit statistics. One source says that the US generates 2700 megawatts. It didn't say where or whether this was electricity or heat. If it's electricity, it's equivalent to two or three large power plants, if heat,, to one plant.

Q. Isn't it vitally important to reduce energy use?

A. No. The demand to reduce energy use is based on the fear of using nuclear energy. Economizing on energy use is no more important than economizing on the production of movies. The world will rely on nuclear energy as its major source in preference to the low standard of living that would otherwise be required. There is little social difference between having (say) 500 nuclear power plants in the U.S. and having 1,000.

New services that might require more energy should not be inhibited. For example, it seems that people are more comfortable when the radiation temperature of a room is higher than the air temperature. That's one reason why people like fireplaces. However, maintaining such a temperature difference would cost money to those who chose to use it and would interfere with minimizing energy use. So what?

Here's an idea for making cities more comfortable in cold weather, but it would use a lot of energy. Make the outsides of multi-story buildings into giant radiators. People walking in the streets will experience Spring in the middle of Winter. I haven't yet calculated the cost in energy. My guess is that it is large but affordable. [Today outdoor restaurants in places where it sometimes gets chilly but not really cold, e.g. Northern California, use large oil heaters to keep the diners warm.]

That's all for energy.

A recent study by the International Institute of Applied Systems Analysis in Vienna gave some scenarios for future energy use.

British Petroleum maintains a useful compendium of energy statistics.

U.S. Energy Information Administration has lots of statistics.

I suppose that the statistics provided by both British Petroleum and by the U.S. Energy Information Administration may be somewhat biased by attitudes of these organizations.

Doesn't every source of energy have energy costs, and isn't the energy cost sometimes more than the energy gained?

Here's an Energy Analysis of Power Systems that estimates the energy costs of various sources of energy with an estimate of the net gain for each source. One source not mentioned for which it has been said that energy costs exceed the gain is alcohol from grain. A lot of energy is used by agricultural machinery and in making fertilizer.

Here's a 1998 December report on subsidies for various kinds of energy. Since such urls often disappear, here's the first paragraph.

Federal subsidies for energy totalled $564 billion (1997 dollars) over the past five decades, most of them "off budget," with oil receiving the most money -- $272 billion (48%) -- and, contrary to common perception, renewable energy (solar, hydro, and geothermal) receiving the second largest subsidy -- $90 billion (16%). The other major U.S. energy sources -- coal, natural gas, and nuclear energy -- received between $61 billion and $74 billion of Federal incentive funds. With respect to R&D funding, coal and nuclear technologies produced the greatest return on investment, whereas photovoltaics, solar thermal systems, and wind systems had the poorest return. The subsidies will impact global warming abatement policies and affect electric utility restructuring programs. These are the major findings reported by Management Information Services, Inc., a Washington, D.C. economic research and consulting firm.

Here's a rather detailed German site on various forms of renewable energy. . As is usual and politically correct these days, it ignores nuclear energy. I also suspect its estimates of the cost of wind energy are over-optimistic.

2002 April: The country that has pursued wind power most vigorously is Denmark. Here are some facts.

  1. Here's a Danish page evaluating Denmark's experience with wind. The page is rather negative. Maybe more enthusiastic pages can be found.

  2. Wind produces 13.7 percent of Denmark's electricity. This comes to 1900 megawatts, which is about the power of the two reactor Diablo Canyon nuclear power station in California.

  3. Wind produced electricity has been more expensive than other sources available to Denmark.

  4. Wind power was a big enthusiasm of the previous socialist government. The new conservative government is unenthusiastic. It threatens to eliminate subsidies for wind power and cancel a planned big wind power farm in the sea.

  5. The biggest problem with wind power has been the intermittent amount of wind. Denmark is a small country, and the amount of wind over the whole country can change in hours. While wind power was a very small part of electricity supply the variability of wind could be readily accomodated by varying other sources. However, at the present 13.7 percent of electricity supply, there aren't enough conveniently variable other sources. Combined heat and power plants are another Danish enthusiasm, and if you need the heat, you get the power whether there is an oversupply or not.

  6. The variability of wind could be compensated if there were a way of storing energy produced when the winds are strong. Various schemes have been proposed, but apparently none have been adopted. Presumably this would require another large subsidy.

  7. Another big problem is the noise. It has resulted in a rule that wind turbines may not be located within 0.5 kilometers of dwellings.

  8. Wind turbines kill birds. A survey in the big wind farm in Altamont Pass in California reports that every seven turbines kill a bird a year. That doesn't seem like a lot to me, because I doubt it would make windmills a major cause of bird death. Bird enthusiasts may take a different view.

Up to: Sustainabilty

Send comments to John McCarthy, jmc@cs.stanford.edu.

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