Thursday, January 31, 2008
The details of the plan are still under review while countries decide to join the partnership. But the general outline is understood well enough to describe here.
First we need to establish an important aspect of proliferation. Nuclear power plants aren't necessary for producing weapon material. The surest way to make bomb material is by enriching natural uranium to weapons grade. If an independent nation has a source of uranium, no other nation has the legal right to interfere with its weapons ambitions. At most, other nations can apply diplomatic and economic pressure on it, as many nations now are doing with no apparent effect on Iran.
There has been so much talk about diversion of spent fuel being a problem, you may wonder why it is that spent fuel isn't a necessary ingredient. The reason is that it's more difficult to make a successful bomb from spent fuel than from uranium ore. It's instructive to look at the history of the Manhattan Project that led to the first atomic bombs. In short, spent fuel contains transuranic actinides that cause the bomb to pre-detonate so the result is a burp instead of a bang.
All this means that the problem of proliferation is irrelevant to the issue of nuclear energy. But GNEP provides a formula by which the partners can offer safe and cost-efficient nuclear energy on the premise that the subscriber nations will prefer the GNEP fuel system over developing their own. The fuel processing and enrichment will be done by nations that already possess that capability.
So GNEP cannot stop any nation from acquiring a bomb. What it can do is offer nations a way to employ nuclear energy without building a capability for fuel processing and enrichment.
Wednesday, January 30, 2008
But as we showed in an earlier article, The Dimensions of the Challenge, windmills and other part-time energy sources will never take the place of coal. Since nuclear is the only energy source that can, it's fair to compare the effects of both kinds of waste.
Nuclear opponents can't point to a single incident in which nuclear power wastes have caused harm to any person or any thing. So let's consider coal wastes, in comparison.
Jeff Goodell's book, Big Coal: The Dirty Secret Behind America's Energy Future (Boston: Houghton Mifflin Company, 2006) makes grim reading. He recounts how coal companies have kept their operating costs down by poisoning the environment. On page 41 he describes the effects of the wastes of one coal mine in West Virginia and how they affect the local residents' water.
In this excerpt, "Massey" refers to Massey Energy Company. Don Blankenship is the CEO.
"A few years ago, Dr. Diane Shafer, a busy orthopedic surgeon in Williamson, the Mingo County seat, noticed that a surprising number of her patients in their fifties were afflicted with early-onset dementia. In addition, she was hearing more and more complaints about kidney stones, thyroid problems, and gastrointestinal problems such as bellyaches and diarrhea. Incidents of cancer and birth defects seemed to be rising, too. She had no formal studies to back her up, but she had been practicing medicine in the Williamson area for more than thirty years, and she knew that many people who lived in the hills beyond the reach of the municipal water supply had problems with their water: black water would sometimes pour out of their pipes, ruining their clothes and staining porcelain fixtures. Many people had to switch to plastic fixtures because steel ones would be eaten up in a year or two. The worst water problems were in the town of Rawl, near Massey's Sprouse Creek slurry impoundment pond, where millions of gallons of black, sludgy water is backed up. Were the health problems in the area related to the pollutants leaching into the water supply from the slurry pond? Dr. Sharer suspected they were.
"Dr. Sharer is the lone physician on the Mingo County Board of Health. Despite her urgings, she could get no one at an official level to take much interest in the water problems in the area. So at her recommendation, a group of concerned citizens contacted Ben Stout, a well-known professor of biology at Wheeling Jesuit University and an expert on the impact of coal mining on Appalachian streams, to study the water quality in the area. Stout tested the water in fifteen local wells, most of them within a few miles of the Sprouse Creek impoundment and one just a short distance from Blankenship's home. Stout found that the wells were indeed contaminated with heavy metals, including lead, arsenic, beryllium, and selenium. In several cases, the levels exceeded federal drinking water standards by as much as 500 percent. Of the fifteen wells tested, only five met federal standards. Stout says that the metals found in the water samples were consistent with the metals in the slurry pond and the most logical explanation for how those metals got into the Williamson drinking water was that the impoundment pond was leaking into the aquifer. He also pointed out that coal companies often dispose of excess coal slurry by injecting it directly into abandoned underground mines, where it can easily migrate into the drinking water.
What if coal wastes had been handled as conscientiously as nuclear-energy wastes have been? It's a pointless question. Coal wastes can't be isolated from the environment because of their massive quantities. Here's what the US Department of Energy says about it:
"Nuclear power produces around 2,000 metric tonnes/per annum of spent fuel. This amounts to 0.006 lbs/MWh. If a typical nuclear power plant is 1000 MWe in capacity and operates 91% of the time, waste production would be 45,758 lbs./annum or slightly less than 23 tons. The solid waste from a nuclear power plant is thus not the volume of the waste, which is very small, but the special handling required for satisfactory disposal. A similar amount of electricity from coal would yield over 300,000 tons of ash, assuming 10% ash content in the coal. Processes (specifically scrubbing) for removing ash from coal plant emissions are generally highly successful but result in greater volumes of limestone solid wastes (plus water) than the volume of ash removed."
There clearly is no environmentally-sound way to dispose of 300,000 tons of ash (or more if the flue gas is scrubbed) at every power plant, every year. As long as we keep on burning coal we'll keep on polluting the groundwater.
Tuesday, January 29, 2008
The reactor at Chernobyl was different from all the other power reactors outside the Soviet Union: it was inherently unstable, meaning that the reactivity in the core went up when it got hotter so that once the operators lost control there was no way to get it back.
The accident happened this way[source]. The night crew was told to perform a test to see if the reactor could sustain a sudden disconnection from the power grid. It happened that the night crew was inexperienced (presumably because of seniority rules), though that probably wouldn't have made any difference. What was supposed to happen was that the flywheel inertia of the turbine blades in the electrical generators would give enough power to run the coolant pump until the diesel-powered generators could start and power up.
The crew didn't know that the reactor was operating at an abnormal condition, having run at full power all day and then being cut back to part load, but that probably wouldn't have made any difference, either.
It's not clear why, but the coolant pumps were run at their maximum flow. Possibly the crew thought they were increasing the safety margin. But the resulting cooler temperatures lowered the steam pressure and water filled more of the reactor's internals. Water absorbs neutrons more than steam does, so the control rods had to be withdrawn to maintain power.
The automatic controls would ordinarily have shut down the reactor under these conditions, so the crew disabled the emergency cooling system and the emergency shutdown rods (usually called SCRAM rods).
The crew disconnected the plant from the power grid. But the pump power from the turbine blades wasn't sufficient so the reactor started heating up. Because of the instability this reactor had, the higher temperature raised the reactivity rate, causing more heating, etc. At that point the reactor was out of control. Steam drove water out of the core, and reactivity increased more. Once the crew realized something was wrong, they inserted the control rods. But the control rods inserted slowly, not quickly as the shutdown rods would have. To make matters worse, the tips of the control rods were made of graphite instead of boron. Graphite raised the reactivity rate instead of lowering it as boron would have done. The rods jammed when they were partly inserted.
The reactor continued to heat up. A steam explosion drove some parts out through the sheet-metal roof that kept rain off the reactor. Finally, the reactor body, which was made of graphite, reached its ignition point. The hole in the roof allowed air to enter and the reactor caught fire.
After the accident, the World Health Organization did an extensive investigation and continual followup; its findings were that actual deaths have numbered about 50 and theoretically there could be as many as 4000 fatal cancers in the future.[source] As tragic as that is, it doesn't approach the death rate due to burning coal. Even in the US, tens of thousands of people die every year just from the pollution from generating electricity with fossil fuels.[Abt Associates Report, Exhibit 6-4]
What's interesting is that a big part of the region around Chernobyl now is healthier than before the accident. The chemical refineries and coal-burning plants caused terrible health problems. Now that they're shut down, the air is clean. Some people have moved back into the parts which officially are quarantined but where radiation isn't especially high. They eat vegetables from their gardens and drink water from their wells, and take eggs from their bug-eating chickens, and they're doing just fine. Wildlife have flourished in the area, including the hot spots. Wildlife biologists are studying the animals and plants and even after all these years they're not finding any radiation-related health problems. There's a superb book on Chernobyl's aftermath: Wormwood forest : a natural history of chernobyl by Mary Mycio.
So what are the differences between Chernobyl-style Soviet reactors and all the power reactors in the rest of the world? There are too many differences to list here, but we'll tick off the major differences that led to the accident.
1. The reactor was unstable.
2. The reactor had no containment structure.
3. The reactor was made of graphite, protected only with a sheet-metal shed. Outside the Soviet Union, power reactors have multiple layers of steel and concrete protection.
4. The crew hadn't been trained for the test it was performing.
5. The crew was working without supervision and went against plant operating regulations.
To understand why the reactor was built and operated so unsafely, you'd have to understand how the Soviet system worked. I'm not qualified to explain it, but if you read some Solzhenitzyn you'll get the idea. The accident did, however, prove that anti-nukes had vastly overstated the harm such an accident could cause. It turned out that the consequences, serious as they were, were of the same scale as disasters that happen every year.
More important, the accident at Three Mile Island in Pennsylvania in 1979 totally destroyed the reactor but resulted in no adverse health effects, which validated the defense-in-depth designs used in all US power reactors.[source]
Monday, January 28, 2008
Here are some excerpts from the article:
Feature Article, 23 October 2004
Why the planet needs nuclear energy
"As a first step towards this goal, our Government has set itself the target of 10 per cent of electricity from "renewables" by 2010, . . ."
"This needs to be rigorously followed up if the 60 per cent reduction of global warming gases is to be achieved in time. So our Government has further set itself the 'aspiration' of 20 per cent of electricity from renewables by 2020. Yet there seems to be little idea how this second target can be achieved."
"This is why nuclear energy is the most viable alternative, but the problem is that it takes several years between a decision to build a nuclear reactor and its commercial operation. If we are to have more nuclear energy soon after 2010 we must plan now. The Government has said that it is keeping open the nuclear option, but the question remains: why aren't our nuclear reactors being replaced as they become obsolete? Nuclear energy, at present supplying 20 per cent of our electricity, provides a reliable, safe, cheap, almost limitless form of pollution-free energy."
"The real reason why the Government has not taken up the nuclear option is because it lacks public acceptance, due to scare stories in the media and the stonewalling opposition of powerful environmental organisations. Most, if not all, of the objections do not stand up to objective assessment. The accidents at Three Mile Island in the United States and at Chernobyl in the Ukraine are usually cited as objections, without much consideration of what happened and what the results were. At Three Mile Island the additional radiation in the surrounding district was less than would be received in one day from natural sources, and no adverse medical effects have been proved."
"The advantages far outweigh any objections, and I can see no practical way of meeting the world's needs without nuclear energy."
Tony Juniper, director of Friends of the Earth, explained the firing this way: "To have us saying one thing and a member of the board of trustees saying the opposite is clearly unworkable in practice. We can't have the organisation saying two things at once."[The Independent (London), Oct 22, 2004 by Michael McCarthy, Environment Editor]
He's right, of course. Party discipline comes first.
Sunday, January 27, 2008
On the other hand, Ms. Caldicott has had no training in epidemiology or health physics. She never has belonged to professional organizations devoted to these subjects and she never has published in a peer-reviewed journal.
The National Center for Public Policy Research assembled some of her more notable quotes, as follows:
"That's the argument Hitler probably used when he built the gas ovens -- jobs. " - Caldicott quoted in the Sacramento Bee, April 26, 1988, equating support for defense industry jobs with support for the Holocaust
"The support for that massacre (U.S. liberation of Kuwait) was skin-deep. People felt oppressed by their government was doing and the country was lost... That whole ordeal in the gulf was a practice round for nuclear war. It was obscene beyond belief." - Caldicott quoted by Dana Tims of the Oregonian, November 13, 1991
"Scientists who work for nuclear power or nuclear energy have sold their soul to the devil. They are either dumb, stupid, or highly compromised... Free enterprise really means rich people get richer. And they have the freedom to exploit and psychologically rape their fellow human beings in the process... Capitalism is destroying the earth. Cuba is a wonderful country. What Castro's done is superb." - Caldicott quoted by Dixy Lee Ray in her book Trashing the Planet (1990)
"As it is, life in America amounts to a corporate dictatorship." - Caldicott quoted by Dana Tims of the Oregonian , November 13, 1991
"At a Beverly Hills fund-raiser... nuclear arms opponent Helen Caldicott gave a controversial speech in which she likened Soviet leader Mikhail Gorbachev to Jesus Christ and suggested the Department of Defense be renamed the 'Department of Annihilation.' " - Amy Chance of the Sacramento Bee, April 26, 1988
"Every time you turn on an electric light, you are making another brainless baby." - Caldicott quoted by environmentalist Theodore Roszak in the Oregonian, June 14, 1992
"[Caldicott] said that if principles crystalized during the Nuremberg Trials at the end of World War II were applied to allied prosecution of the Gulf War, hangings of the U.S. military brass would be in order." - Dana Tims quoted in the Oregonian, November 13, 1993, after conducting a telephone interview with Caldicott
Here's the scary part. Ms. Caldicott is a leading light, an intellectual paragon, among anti-nukes.
Saturday, January 26, 2008
Whatever anyone could want a nuclear power plant to do, these sweethearts deliver.
They can't go out of control and overheat. You can shut off the cooling at full power and they just warm up a little and stop. They're made in modules; you get whatever size you want by assembling modules. You want small? Buy one module. You want big? Buy a bunch. They don't require heavy forgings so they can be mass-produced. They're cheap. They never have to shut down for refueling. They're gas-cooled so water chemistry is never an issue. They can drive hydrogen generators while generating electricity. They are so safe they can be built close in; the leftover heat can be used to heat homes and businesses instead of heating up the outdoors.
How is all this possible, you're wondering. Here's the deal:
The big bugaboo with conventional reactors is that the fuel elements stay in the reactor for a long time, a couple of years or so. During that time they build up fission products that give off heat even when you shut the reactor down. So the challenge is to ensure that cooling is always available to the core, no matter what. You may recall that during the Three-Mile-Island accident the operators deliberately turned off the cooling pumps and, sure enough, the core overheated and melted.
The concept here is to continually refuel. The fuel elements only spend a couple of weeks in the reactor before they are put into storage and the few fission products they hold are allowed to decay away; then they are cycled back through the reactor. Actually, a number of concepts for doing this have been proposed; it happens that the PBMR is the concept going into commercial operation.
How it works is that spherical fuel elements, called pebbles, are fed into the top of the reactor while others are withdrawn at the bottom. The pebbles are mixed graphite and uranium, coated with an abrasion-resistant ceramic. They're like billiard balls.
The design feature of greatest interest is that the reactor has a strongly negative void coefficient, which is a physicist's way of saying the reactivity rate goes down when the temperature goes up. So they don't need control rods or shutdown rods, although some versions have them. You control the power of the reactor by controlling the flow of gas coolant through the pebble bed. If you want less power you cut back the flow of gas; as the temperature rises the reactivity rate drops. If you want no power you shut off the flow; the temperature rises to the shutoff point and the reaction stops.
Could all reactors be this kind? Possibly. The catch is that the world probably will need some advanced-cycle reactors and an advanced-cycle PBMR hasn't been invented yet. So it could be that the future will include a mix of PBMRs and advanced-cycle reactors.
In the meantime, customers in China and South Africa are trying them out.[source]
Friday, January 25, 2008
The reasoning he offered was like this: if the US recycled its spent fuel, North Korea would make atomic bombs. And if the US didn't recycle its spent fuel, North Korea would not make bombs.
You can quickly see that this argument overlooks a basic fact, that North Korea's bomb-making decisions did not depend in any way on whether or not the US recycled its spent fuel. And it led ineluctably to a solid blockage at the back end of the nuclear fuel cycle.
The plan all along had been to reprocess spent fuel. Reprocessing the wastes separated out the valuable uranium and transuranic actinides to use as fuel. The remaining wastes were only 3% of what was there before and would lose their toxicity in some centuries; five would be sufficient. [chart] Many geologic places, such as caves or abandoned mines, could store those wastes safely.
But the decision by that president changed everything. Suddenly there was no way to deal with the spent fuel. It had to be stored at the reactor plants where it had been generated. Not only did the volume of waste go up by a factor of thirty, it would stay dangerous for many thousands of years, even hundreds of thousands. There was, and is, a federal law that utilities are not allowed to process or even permanently store the spent fuel. That meant that the Department of Energy had to find a geologic location where the waste could be isolated for thousands of years.
It happened that this change transpired at a time of fervent opposition to nuclear energy, and nuclear opponents fomented public protest in all the candidate locations for the permanent repository. Finally, the US Congress decreed in 1987 that the location would be Yucca Mountain, Nevada.[Timeline] Nevadans were not favorable to this decision; Nevada had more vacant jobs than workers in need of them and saw no gain for themselves in such a facility. Nuclear opponents focussed on the area and in no time most state residents believed that Yucca Mountain was the worst possible location for a spent-fuel repository anywhere in North America and knew at least a dozen reasons why.
As the site evaluation proceeded, features were discovered that would raise the cost many times above the initial estimate and also would lengthen the time to do the work by years. But the biggest blow came in 2004, when the U.S. Court of Appeals in Washington, D.C. ruled that the repository would have to ensure safe storage for at least 300,000 years, as far into the future as Homo rhodesiensis lived in the past.[Timeline]
Almost anti-climactically, word leaked out in 2005 about some casual e-mails between analysts five to seven years earlier. They were chatting about pressure from managers to slant their conclusions, and about filling in software documentation after-the-fact; the sort of private ruminations in which officeworkers engage. Opponents of the project seized on these stories as proof of falsifications in the analysis. Later investigations resulted in no actions being taken against the participants.[source]
Presently, the Energy Department plans to submit its application to the Nuclear Regulatory Commission this year and the review process will take at least three years. It's possible that the repository could go into service as early as 2017.[Timeline] But leading elected national officials have declared their intentions to stop the project.
So that's the story of Yucca Mountain. It all happened because of a bad presidential decision made decades ago. Fortunately, that decision has been reversed and we're going back to the first plan. Not only does it solve the waste problem, but it stretches the supply of uranium.[source]
Thursday, January 24, 2008
But the subject of subsidies is altogether different, and that is the point of this article. I am only covering the US situation; I don't understand what goes on in other countries. I don't fully understand what's going on in the US and I don't think anyone else does, either. But the reason this comes up is that nuclear opponents wish to prove that nuclear energy costs more than its price shows; that if it weren't subsidized it would be hopelessly expensive.
The first murky issue is, what constitutes a subsidy? A subsidy is supposed to be a transfer of money (or possibly property) to an economic entity as a financial benefit. No energy sources get subsidies. But a tax credit is the same thing, so all energy sources get subsidies.
In the current energy plan, the first 6000 MW of new advanced-design nuclear plants can receive up to 1.8¢ per KWH in tax credits for up to 8 years. Up to six new plants could qualify for a subsidy to offset the cost of designing and permitting.[source] Clean renewable sources can receive up to 1.9¢ per KWH for up to 10 years.[source]
So those seem clear enough. But plants are also offered loan guarantees. That clearly benefits the utilities that build them. It also benefits investors. But it only costs taxpayers if the utilities default on the loans. So is that a subsidy? And if it is, how does one evaluate the probability of a default?
Nuclear opponents always cite federal underwriting of nuclear insurance as a subsidy. That could be considered a benefit, but it only costs the taxpayers if there's an accident exceeding 10 billion dollars in damages. In the history of the program, taxpayers have never paid out a cent. Is that a subsidy? And if it is, how does one evaluate the probability of an accident?
Nuclear opponents consider money spent in the past on research and development to be a subsidy. But the R & D money went to make nuclear plants safer, not cheaper. In fact, the research achievements raised the cost to utilities because they had to upgrade their plants when new technology became available. It could be that the superior technology prevented expensive accidents, but the main beneficiaries were members of the public. So, should R & D expenditures be considered a subsidy?
But these considerations don't slow nuclear opponents down for a second. They throw numbers around as if they meant something, and never try to justify them. Here are some examples:
"In the last 50 years, nuclear energy subsidies have totaled close to $145 billion; renewable energy subsidies total close to $5 billion."[prwatch.org]
"Between 1948 and 1998, the federal government spent $111.5 billion on energy research and development programs. Of this amount, 60 percent, or $66 billion, was dedicated to nuclear energy research, and 23 percent, or $26 billion, was directed to fossil fuel research."[PIRG]
"Management Information Services, Inc. (MISI), conducting a study of the cumulative effects of energy subsidies, found that by 1997 Federal subsidies for energy had amounted to $564 billion (1997 dollars) over the last five decades, roughly half of which went to the oil industry in the form of tax expenditures. MISI considered eight categories of Federal activity and quantified subsidies in six. In contrast to other findings, MISI found that subsidies to renewable sources ($90 billion) outpaced those to natural gas ($73 billion), coal ($68 billion), or nuclear energy ($61 billion)."
"While the bill's environmental objectives are a strong advance, one provision remains misguided. Despite the provision of billions of dollars in subsidies to the nuclear industry in the 2005 Energy Policy Act and over $85 billion in historical subsidies, the bill introduced today contains additional nuclear subsidies that NRDC continues to oppose."[NRDC]
But let's take the wildest of the these guesses, prwatch.org's 145 billion dollars. Spread over the 17,111 billion KWH nuclear plants have generated, the cost of this purported subsidy is 0.8¢/KWH. In contrast, the subsidy for geothermal, wind, and solar, using prwatch.org's 5 billion dollars spread over 485 billion KWH, would be 1¢/KWH. Or, if we use MISI's estimates, the subsidies would be 0.4¢/KWH for nuclear and 18¢/KWH for renewables.
If we were to believe nuclear opponents, they all are stalwart Defenders of the Public Purse. They are deeply concerned that taxpayers will have to support uneconomic nuclear power plants. Renewable energy sources are different, though. Taxpayers should be glad to support them.
But these numbers show that this is all a red herring. Even if we accept nuclear opponents' exaggerated projections of nuclear subsidies, most renewables still won't compete. On economic grounds, the choice is between nuclear and coal.
So why is coal so cheap? It's because the federal government has a deliberate policy of allowing coal-burning utilities to emit so much pollution into the air that thousands of Americans die every month, all in the interest of holding down electricity rates. Just counting deaths among adults over 25, the estimate ranges from 33,000 to 121,000 per year in the US [table]. Nuclear energy can't compete with coal and neither can anything else, not even conservation.
Subsidies for nuclear energy are not necessary. If air-pollution controls were adequate then windpower, nuclear, and conservation would all be cost-competitive. But if we set a policy that coal-burning utilities are free to poison the air, and we want at the same time to make them stop operating, then we can't just leave it up to the market to decide.
Wednesday, January 23, 2008
In the same way, anti-nuclear political organizations have succeeded in convincing people that nuclear energy is a threat to the environment. As we have discussed in earlier articles, nuclear energy has the best safety record and the best environmental record of any practical energy source. It also is essential to minimizing global warming. But anti-nuclear activists have cloaked themselves as Defenders of the Environment and by constantly hammering people with the same slogans they've made people so secure in their misconceptions that most never have looked at the issue plainly.
Eric Hoffer knew the value of anti-nuclearism before it even existed when he wrote about true believers:
"When Hitler was asked whether he thought the Jew must be destroyed, he answered: 'No. . . . We should have then to invent him. It is essential to have a tangible enemy, not merely an abstract one.'"
So nuclear energy has been enormously valuable to political organizations. They can command immediate obedience from their followers by continually fabricating misinformation.
Consider the pollution from coal. Thousands of Americans die every month from the air pollution generated by coal-burning power plants. Please see the Abt report, "The Particulate-Related Health Benefits of Reducing Power Plant Emissions." [http://www.abtassociates.com/reports/particulate-related.pdf]. It's a long report, very technical; if you like, you can just look at the results table Worldwide, the deaths certainly run in the tens of thousands every month. Coal pollution is the main source of lead in the ocean; fish now are so poisoned with lead that people are advised to limit their consumption. When whales beach themselves and die the carcasses have to be treated as hazardous waste because of the heavy metals they contain.
But environmental groups have offered only token opposition to coal pollution. When confronted directly, they'll answer, Oh, we're against coal too! Then they'll explain that nuclear versus coal is a false choice, that windmills will solve the world's energy needs. Here's an experiment: if you find one of these people, ask him where the energy will come from when the wind isn't blowing and the sun isn't shining. I guarantee he'll change the subject.
This debate has always been one-sided. The anti-nuclear political organizations have set up a straw man to fight against: the Nuclear Industry. In their presentation, the Nuclear Industry is directing a massive, well-financed campaign and only the stalwart Defenders of the Environment are standing between Good and Evil. Actually, the big players in nuclear energy always have been energy companies, not nuclear companies. Westinghouse, General Electric, Exxon, etc. are glad to provide whatever kind of energy utilities and their ratepayers are willing to take. There never have been powerful groups able to take on Greenpeace or Friends of the Earth or any of the anti-nuclear political organizers. In the US, an industry group called the Nuclear Energy Institute is struggling to get good information over the shouting of the nuclear opponents; it's like your high-school basketball team going up against the Lakers.
But the dishonesty goes deeper. Nuclear opponents don't just spread misinformation and exaggerate the strength of their opponents. Besides that, they shed themselves of all responsibility. The easiest position to take is the one that never will be tested. Despite their unwillingness to admit it, they know as well as you and I that the world never will depend on part-time energy sources. So no matter what happens they'll be able to say that the world should have done it their way.
This self-indulgent preening shouldn't be allowed to affect public policy.
Tuesday, January 22, 2008
Note, if you will, that fossil-fired electricity accounts for only 6.5% of the energy even though it accounts for 40% of the CO2 emissions.
This analysis comes in two parts. First we'll cover electricity. We know the rate of electricity generation will go up because a lot of the schemes for reducing greenhouse-gas emissions require shifting fossil-fuel applications to electricity: battery-powered cars, light-rail transit systems, replacing furnaces with heat pumps, etc.
Renewable energy sources such as wind and solar can't replace fossil fuels owing to their part-time natures. But they can greatly reduce the amount of fossil fuels being burned during the transition period while renewable and nuclear sources are being installed. So our plan includes both renewable and nuclear.
But wait, there's more! Electricity is a big part of the problem but not the only part. We also have to replace petroleum-based motor fuels. At this point, there are only two possibilities in view, besides electrified vehicles, bicycles, foot travel, horseback, rickshaw and some other specialized transportation modes. The two possibilities are hydrogen and hydrogen-enriched biofuels, as we discussed in the article, "The Dimensions of the Challenge." Our plan needs to include the capability of producing large amounts of hydrogen. This plan does that, because nuclear plants allow for thermochemical production of hydrogen, by far the most efficient technique available.
Once all the fossil-fired power plants are replaced, nuclear and renewables can complement each other. The nuclear plants can provide whatever electricity is needed during times of dim sunlight and low winds, or no sunlight and no wind. When the sun is shining and the wind is blowing, and when demand for electricity is low, nuclear plants can divert some of their capacity to generating hydrogen.
This plan allows solar and wind to play their maximum part in providing electricity. Further, it allows them to contribute efficiently to the production of hydrogen.
I don't want to claim that this is the only energy plan that could work. But it is the only plan I've seen that could work. If you know a better plan we'll do it your way instead. However, if your plan doesn't allow for providing electricity when the sun isn't shining and the wind isn't blowing then you don't have a plan.
Monday, January 21, 2008
For example, the United States transformed itself from an agricultural nation in the depths of an economic depression into an industrial giant able to manufacture the hardware needed to defeat the Axis powers in five years even with millions of its able-bodied men and women in military service. Compared with that, converting energy away from fossil fuels is easy.
The problems arise from attitude.
First there is the problem of skepticism about global warming. The evidence isn't just strong, it's conclusive. Yet people have made up their minds not to accept it. You can find them on the web even if you don't want to. Any criticism of the Intergovernmental Panel on Climate Change, justified or not, from any person, qualified or not, is touted to be the final "debunking" (a term much in fashion) of climate-change science.
Overcoming this obstinacy should be the easiest part of the problem to solve, but we can't even accomplish this much.
Next is the perverse refusal of nuclear opponents, all of whom claim the mantle of Defenders of the Environment, to acknowledge the clear necessity of nuclear energy for minimizing climate change. The same Defenders of the Environment deny both the environmental benefits of nuclear energy and the limitations of part-time energy sources.
We see some erosion of this monolithic inertia among more thoughtful members of the public, but the executives at the major international anti-nuclear political organizations aren't budging.
Then, assuming these problems can be overcome (or possibly ignored), we face the difficulty of implementing solutions.
Perhaps there will be local opposition to construction of nuclear power plants. But wind farms already are seeing fierce opposition. And the fights over solar panels haven't begun. When utility ratepayers realize how much they're paying to subsidize their neighbors' rooftop panels they'll do one of two things. Some of them will decide to cash in on the program. But if too many people do that the program will collapse from the expense. So all the people left out will see their rates go up dramatically. Before it's over you will hear people say they wish they'd never heard of solar energy.
What's left is conservation. And conservation is always the preferred nostrum; whenever energy and global warming come up, conservation is always our best and brightest hope.
But conservation means more than putting in compact-fluorescent lightbulbs and recycling wine bottles. It even means more than junking our SUVs and buying hybrid cars. It means smaller houses and no vacation homes. It means giving up motorhomes and cabin cruisers and recreational flying. No more flying vacation trips.
Sounds discouraging, no? It is discouraging if stubborn, misinformed people are allowed to dictate the world's energy future. But there is a way to solve this, and that will be the next articles's subject.
We will compare the different non-fossil energy sources that have been proposed with respect to their capabilities. Where appropriate, we will compare the land areas required for each with the land area available.
First, consider the amount of electricity the US uses, a total of just over 4 billion MWH/year.[source]
What really limits wind power is the small amount of storage available; hydroelectric dams can treat a small part of their capacity as short-term storage for wind power. For the purpose of this calculation, we shall pretend that the limitation doesn't apply but we'll discuss storage later in this article.
Currently, typical wind-turbines on wind farms are sized at 1.5 MW, with a rotor-tip height of 450 feet and a rotor diameter of 231 feet.[source][source]. Allowing a generous load factor of 0.35 [source], each turbine yields 4602 MWH/year, so 869,000 turbines would be required. The minimum turbine spacing recommended is five times the rotor diameter [source], so each 1.5 MW turbine requires (5 X 231 ft)^2 = 1,334,025 feet, or 0.048 sq mile.
To provide all the electricity the US uses would require more than 41,720 square miles. That would be a strip of land 40 miles wide running from the Montana/Canada border to the Arizona/Mexico border. To get good efficiency, a strip 60 miles wide would be needed.
Solar energy has the same storage limitations as wind power, but we still shall pretend that the limitation doesn't apply.
For the US, an average insolation would be around 5.5 KWH/m^2/day[source], or 2 MWH/m^2/year. Allowing a generous 20% efficiency[source], the output would be 0.4 MWH/m^2/year. To provide all the electricity the US uses would require 10 billion square meters or 3861 square miles of solar panels. That would be a panel 1-1/2 miles wide running from San Diego to Boston.
Nuclear plants are operating at about 90% capacity factors.[source]
However, new ones will run somewhat lower, so an average capacity factor of 80% will be assumed.
For 1000 MW power plants, 571 would be required to provide all the electricity the US uses, compared with 104 that currently are in operation.
Up to now, this discussion has ignored the difference between peak power demands and gross power generation. In the case of solar and wind power, it didn't matter because neither can reliably supply energy at any time, let alone meet peak demands. Nuclear power is available at all times, though, so peak demand can be met. The current US electric capacity is about 890,000 MW[source], so about a thousand 1000-MW power plants would be required, or a smaller number of larger plants.
The US uses about 140 billion gallons of gasoline per year.[source] Since ethanol has only 70% of the energy content of gasoline[source], at 439 gallons per acre[source], the US would have to plant 456 million acres, or 713,000 square miles in corn to displace gasoline with ethanol. That is about one-fourth of the area of the 48 contiguous US states.
The US consumes 63 billion gallons of diesel fuel per year.[source] The land area required to grow enough soybeans to displace the petrodiesel with biodiesel, at 63 gallons per acre[source], would be one billion acres or 1,563,000 square miles, about half of the area of the 48 contiguous US states.
These calculated land areas seem too high to be correct, but they are in line with calculations done by others. For example, this analysis finds that, if all vehicles were diesel-powered, the land area required would be 58% of the US including Alaska. Another calculation shows that if all the corn and soybean crops in the US were converted into biofuels they would replace just 12 percent of the gasoline used and just 6 percent of the diesel fuel.
Of the land in all of the US, only 18% or 650,000 square miles is arable[source], and most all of that is being cultivated for food and fiber. Also, the calculations shown above assume that all the land would have the same yields as the prime farmland currently under cultivation and that there would be sufficient water for irrigation. Neither of those conditions is true, of course, so plainly there isn't enough land.
Clearly, biofuels won't provide much liquid fuel. There is a possibility that these land requirements can be reduced by two thirds if hydrogen is injected into the biomass during processing. For example, 0.77 gallons of biodiesel can be produced by adding 1 kg of hydrogen[source], which requires 39.3 KWH of energy to produce from water. The biodiesel equivalent of US diesel consumption is 70 billion gallons per year; to produce enough hydrogen would require 2.75 trillion KWH per year. The fact remains, though, that biofuels can only be part of the solution.
For a long time, fuel cells have been the holy grail in the quest to free the world from fossil-based motor fuels. The barrier seems to be the catalyst; platinum so far is the only material that works. Not only is it very expensive, several thousand dollars per vehicle [source] but if fuel cells drove up the demand then the cost would be even higher. There also is the unsolved problem of storing enough hydrogen on board for a reasonable driving range. But suppose these problems could be overcome.
As a rough estimate, let's say the amount of hydrogen needed would be the energy-equivalent of 100 billion gallons of diesel fuel per year, chosen mainly because it's a round number about half of the total of gasoline and diesel fuel: 50 billion gallons probably is too little and 150 billion gallons probably is more than necessary. The heat value of diesel fuel is about 38 KWH/gallon[source], so our energy equivalent is 3.8 billion MWH/year. For our rough purposes, this is the same as our current electrical usage.
Unfortunately, the process for converting water to hydrogen at normal temperatures is less than 30% efficient. So, the electricity required would be more than three times our current electrical usage. To generate that much electricity with solar panels would require a panel 5 miles wide running from San Diego to Boston. To generate the electricity with wind turbines would require a strip of land 130 miles wide running from the northern Montana border to the southern Arizona border with 2,870,000 turbines, all rated at 1.5 MW.
It is possible to produce hydrogen efficiently in a thermochemical process, using nuclear-generated heat. The nominal efficiency is over 45%.[source] But the heat left over from the conversion can be used to generate electricity, so the hydrogen production is nearly 100% efficient. The nuclear plants can produce electricity and hydrogen at the same time. More power plants aren't required because the additional heat will be available during off-peak hours.
Currently, hydrogen storage is the weak link. It's practical only for local transportation, but intense research is underway.
Bulk Energy Storage
Pumped Energy Storage
The purpose of this admittedly rough calculation is to estimate the amount of pumped storage that would be required if wind power provided all the electricity the US uses.
First, consider the amount of electricity the US uses, a total of just over 4 billion MWH/year.[source] On an average day, not a high-demand day, that's 11,000,000 MWH/day.
We have to make up a fictitious example because there aren't any real examples. Suppose we use Lake Erie, Niagara Falls, and Lake Ontario as our pumped-storage, pretending that we could increase the capacity of the turbines enough.
We know that Niagara Falls' power capacity is 2400 MW, using 375,000 gallons/second of water.[source] We also know that the capacity of Lake Erie is 484 cubic kilometers of water, which is 128,000 billion gallons.[source] At present, the falls could produce 57,600 MWH/day, using 32.4 billion gallons/day. So, to serve all of the US for one day, the water required would be (11,000,000/57,600) X 32.4 billion gallons = 6,187 billion gallons, which is 4.8% of Lake Erie. That means that Lake Erie could provide storage for three weeks.
How much storage would be required? Looking at data for all of the US, we see that, with surprising consistency, low-wind months have average speeds about 70% of the average speeds for the high-wind months.[source] Based on the cubic relationship between wind speed and power, we would expect seasonal variations in energy generation of around 0.35 to 1, so the average would be something like the rated capacity times (1 + 0.35)/2 or 0.675. Conversely, for the generation to equal the load, the rated capacity of the wind farms would have to be the yearly average load divided by 0.675, or multiplied by 1.48. Since we can expect the generation in a slow-wind month to be 0.35 times the rated capacity, the storage capacity would have to be about 1 - 0.35 X 1.48 (= 0.48) times the yearly average load times the length of the low-wind period.
21 days' capacity would be good for 21/0.48 = 43 days of low winds. But low-wind seasons last longer than 100 days.
The power grid allows for some redistribution of power from areas experiencing high winds to areas with low winds. But the wind-variation patterns cover large regions so there are limits to what can be achieved. Allowing for redistribution still leaves a need for more than three-weeks' capacity.
To provide adequate pumped-storage capacity for wind power as the main electical-energy source for the US would require damming canyon streams to create twin lakes around the country equal in volume to something bigger than Lakes Erie and Ontario. Even if enough locations could be found, the projects would not be permitted because of the high ecological cost.
Another scheme that sometimes is mentioned is storing compressed air in caves. There is a facility in Huntorf, Germany that we can use for an example.[source] It compresses air to 1000 pounds per square inch pressure.
The data show that it stores 3 x 290 = 870 MWH of energy and the cave volume is 310,000 cubic meters.
For one day of electricity storage for the US, the volume needed would be
11,000,000/870 X 310,000 = 3.92 billion cubic meters = 138.4 billion cubic feet.
Suppose a cave had an average cross-section of 50 ft X 50 ft = 2500 sq ft.
For one day's electricity storage, the cave's length would have to be 138.4 billion / 2500 = 55.34 million feet = 10,490 miles. Granted that most big caves have never been surveyed, it's still safe to say that there aren't ten-thousand miles of caves in the US. So there is no possible way enough energy could be stored to see the country through 100 days of low winds.
Barring some startling new energy development, what all this shows is that solar panels and wind turbines won't provide major parts of the world's energy; biofuels can only be important if a large amount of hydrogen is available. If global warming is to be avoided, the only two technologies that can provide sufficient energy are nuclear and hydrogen.
In the next article we'll look at the obstacles to solving this problem. In the article after that we'll see a scheme for reducing the consumption of fossil fuels.
Sunday, January 20, 2008
But the biggest international environmentally-oriented political organizations oppose nuclear energy and in the strongest terms possible. How can this obvious contradiction be explained? A close look at the record of these same organizations makes clear what has happened.
Please take a look at this scorecard. It shows that, for all their self-praise, these organizations have a poor record. It also includes descriptions of how they got to be so ineffective, from the viewpoints of insiders.
Besides a stubborn unwillingness to look at environmental problems that matter, anti-nukes also have in common a total misunderstanding about the ability of various energy sources to meet the world's present needs and no imagination about the world's future needs. We'll discuss the limitations of the various energy alternatives in the next article; later on we'll discuss future needs.
Saturday, January 19, 2008
The waste materials from nuclear energy are at most a hypothetical concern. No person has ever been harmed by them. Despite that, people who oppose nuclear energy do so mainly because the wastes stay radioactive for a very long time, even hundreds of thousands of years. It's odd that the same people don't have problems with coal wastes, which pile up in vast heaps and sludge ponds that stay toxic forever.[source]
Until recently, the plan was to bury the wastes in geological structures where they would be safe until the radioactivity decayed away. But now the plan is to reprocess the wastes to separate out the valuable uranium and transuranic actinides to use as fuel. The remaining wastes are only 3% of what was there before and lose their toxicity in much less time, hundreds of years instead of hundreds of thousands.[source] Many geologic places, such as caves or abandoned mines, could store those wastes safely. Besides that, proven technology exists to irradiate the wastes into other, shorter-lived materials.[source] To deal with the wastes this way doesn't require any technological breakthroughs, just a political decision.
There is a common misunderstanding that nuclear power plants are a requirement for making bombs. That is not the case, as explained by Hans Blix, a former Director of the IAEA, the United Nations agency responsible for preventing proliferation [source]:
"A phasing out of nuclear power in some or all states would not lead to the scrapping of a single nuclear bomb.
"States can have nuclear weapons without nuclear power though it is not common today. Israel is a case in point. It has no nuclear power but is assessed to have some 200 nuclear warheads. For a long time China had only the weapons. Indeed, most nuclear weapons states, including the US, had weapons before they had power. "
Despite that, people have a concern that nuclear fuel could be diverted and used to make a bomb by someone who shouldn't have one. This concern overlooks the fact that, even assuming someone could defeat the security measures for protecting the material and somehow ship it to his own facility, the material has to be treated with chemical separation and isotope separation and enrichment. This is a major industrial operation. In every case where it has been done, it required a nation's best minds and vast capital resources. And there still remains the problem of learning how to make a bomb go off. If a nation decides to make a bomb and is willing to make the investment, it can make it from natural uranium; stealing fuel is not a requirement.
A possibility of dirty bombs comes up in some discussions. The concern is that a terrorist could get his hands on spent fuel and blow it up with conventional explosives. That is a possibility, and puts it in the class of other threats, such as chlorine or ammonia or explosives made from fertilizer. But spent fuel is unattractive to terrorists for several reasons. One is that it's monitored in shipping and it's highly likely that the thieves would be caught and the terrorist plot would be exposed. Another is that it has to be heavily shielded so it would take a huge explosion to spread the waste. Another is that the radioactive material is easy to detect; people who are contaminated can be decontaminated quickly and cleanup crews can clean up the contaminated area. Of all the things we have to concern ourselves with, dirty bombs don't rank very high.
This finishes up the initial series of blogs. What they show is the following:
- Global warming is happening.
- Global warming is caused by artificial greenhouse gas, mainly carbon dioxide.
- There's a possibility global warming could reach a tipping point, after which there's no way to fix the problem.
- To prevent global warming, carbon-dioxide emissions have to be minimized.
- To minimize carbon-dioxide emissions will require all the renewable energy we can manage, all the nuclear plants we can build, and more conservation than anyone wants.
In future blogs we'll cover some of the same issues in more detail.
4) Nuclear Energy
Pros of Nuclear Energy
Nuclear energy has the best safety record of any energy source. No member of the US public has been killed or injured by any nuclear plant. This is a key point, because many people are under the impression that nuclear plants are wildly dangerous. The Chernobyl accident in Ukraine in 1986 showed what the actual scale of an accident could be without normal safety provisions. After the accident, the World Health Organization did an extensive investigation and continual followup; its findings were that actual deaths have numbered less than 50 and there could be as many as 4000 fatal cancers in the future.[source] As tragic as that is, it doesn't approach the death rate due to burning coal. Even in the US, tens of thousands of people die every year just from the pollution from generating electricity with fossil fuels.[Abt Associates Report, Exhibit 6-4] More important, the accident at Three Mile Island in Pennsylvania in 1979 totally destroyed the reactor but resulted in no adverse health effects, which validated the defense-in-depth designs used in all US reactors.[source]
Nuclear energy is clean. Since reactors emit no pollutants they are as clean as any of the renewable energy sources that have been suggested.
Nuclear energy is abundant. At current usage, the world's known uranium reserves producible at less than US$60 per pound of U3O8 will last 85 years. Geologic data show that the supply is over 600 years. At higher prices, the supply is even greater. With advanced fuel cycles, the proven reserves would last over 2500 years.[source]
Nuclear energy is economical. Presently, it is cheaper than any energy source except hydroelectricity. Both of them are cheap because the capital costs have all been paid back. Here are average operating costs in the US in 2005, in cents per KWH[source]:
|Gas Turbine and Small Scale||5.885|
For new plants, of course, the cost would be higher because of the capital costs. Here are comparisons for different energy sources [source]. The costs are in UK pence/KWH.
|Nuclear fission plant||2.3|
|Coal-fired pulverised-fuel (PF) steam plant||2.5|
|Coal-fired circulating fluidized bed (CFB) steam plant||2.6|
|Coal-fired integrated gasification combined cycle (IGCC)||3.2|
|Onshore wind farm||3.7|
|Offshore wind farm||5.5|
|Wave and marine technologies||6.6|
Note that the coal-fired electricity costs more than nuclear, which no doubt is because advanced-technology plants are being considered in order to minimize pollution. If older-technology plants were being priced, the cost would be somewhat less, probably less than any of the costs shown.
Nuclear energy is effective against climate change. Comparing life-cycle greenhouse-gas emissions, nuclear ranks with the cleanest of all electric-energy sources in tonnes CO2-equivalent per GWeh.[source]
|Combined-cycle natural gas||469|
Furthermore, most of the solutions to replacing petroleum-based motor fuels require hydrogen and the most efficient way to convert water to hydrogen is with high-temperature processes, at temperatures nuclear reactors can provide. In particular, hydrogen can be added to biomass to triple the output of biofuels; that could make biofuels a major alternate fuel.[source] The nominal efficiency is over 45%.[source] But the heat left over from the conversion can be used to generate electricity, so the hydrogen production is nearly 100% efficient.
So those are the points in favor of nuclear energy. In the next article we'll go over the arguments against.
Wednesday, January 16, 2008
Residential Energy Sources
Some important savings can be made by making greater use of natural energy sources. Home heating and residential water heating could be switched almost entirely to solar and solar-heat-pump systems. Passive solar heating techniques can be built into homes. The remaining residential applications would mainly be cooking, which could almost entirely be converted to electricity. These changes would reduce CO2 emissions by 367 million metric tons, or 6.1% of the total.[source]
Wind power is already providing some electricity at a price which is only a little higher than electricity from fossil-fired power plants.[source] What limits wind power is the need for storage, since neither homes nor businesses can stop functioning when the wind power is unavailable. Currently, only one form of bulk storage is available for energy: existing hydroelectric dams, which account for 6.6% of total US electrical capacity.[source] There are limits to how much storage can be used, since dam operators have to maintain minimum water flows and also have commitments to irrigators, but it's conceivable that wind power could provide a few per cent of the country's energy.
If some sort of bulk energy storage could be developed, that could make wind energy practical. The storage method closest to practicality is pumped storage. In fact, there is a small amount of pumped storage in use now. A rough calculation shows, however, that there aren't enough places to install pumped storage for wind power to become the main electricity source.
A different strategy would be to have fossil-fired power plants standing by to back up wind power. Since wind turbines have a load factor of 25 to 35%, that would seriously hamper the effort to reduce greenhouse-gas emissions because the fossil-fired plants would have to operate a large portion of the time.[source] But the existing fossil-fired plants will be around for some decades while replacement capacity is built. In the meantime, they can be used as backup for wind turbines and other renewable sources. So, in the short term, wind power can be a major power source until replacement sources are constructed and the wind turbines wear out.
Solar photovoltaic systems are presently too expensive to compete with other energy sources, but over the years can be expected to become cheaper.[source] They already are becoming popular in remote locations where connecting to the electrical grid is impractical. If costs continue to fall, solar energy can complement wind power but the unavailability of bulk storage will apply to solar energy as well.
Geothermal energy presently supplies 0.34% of the energy used in the US.[source] There are two types of geothermal energy: wet and dry. The wet type is being exploited about as much as it can be. There is a lot more available in dry form; unfortunately, there aren't any practical ways of extracting it.
Biofuels represent a possibility. To use them unblended as motor fuels would require new engine designs, but that will be unavoidable with any change from petroleum-based fuels. Currently, the best estimate is that it takes 0.75 gallons of fuel to produce the energy-equivalent of 1 gallon of conventional fuel. That's only true if credit is given for the value of the leftover material as animal feed; once the demand for animal feed is satisfied, the payoff ratio won't be as good. It is believed that the fuel input could be reduced to as little as 0.4 gallons with advanced technology that allows agricultural waste to be used as the raw material.[source] Agricultural waste is what gardeners call mulch; it hasn't been determined what would be the adverse consequences of diverting mulch away from fields. Research is being done on different biomass plants and chemical processes that could give better results.
The International Energy Agency estimates[source] fossil-fuel use at 388 exajoules per year worldwide, which may be expected to double or triple in this century. It also estimates that to supply 300 exajoules/year, a goal attainable with moderate effort, would require 7% of Earth's landmass, requiring forest clearing and insecticides and synthetic fertilizers. In comparison, 13.3% of the landmass is arable, including 4.7% already under cultivation.[source] The IEA concludes that biofuels can be an important means of reducing greenhouse-gas emissions on a global scale. For the US and Europe, though, given their limited free agricultural land and their high dependence on liquid fuels, the main effect would be switching from oil-rich suppliers to land-rich ones. Presumably, the benefit of reducing global warming would justify the higher cost.
Many other systems have been proposed: wave engines, tidal engines, and ocean-thermal-gradient engines, to mention only a few. People have suggested micro-hydroelectric power, installing small turbines on thousands of creeks and streams, but never have addressed the legal obstacles to extinguishing hundreds of species. Fusion research continues apace, but no projections are made regarding when it could become practical. Schemes have been suggested for energy storage, such as compressing air in caves, or building mammoth flywheels. All of these ideas are exactly where they were over thirty years ago: nowhere.
But one idea has real potential: hydrogen. Presently, hydrogen use is hampered mainly by the low energy efficiency (around 30%) of converting water to hydrogen at ordinary temperatures.[source] There are more efficient processes, but they require high temperatures and are poorly suited to renewable energy sources. Alternatively, research is going on to improve the efficiency of photosynthetic production, currently around 2%.[source] If the efficiency could be improved, then there is a real future for hydrogen. Storage technology is ahead of production technology, and fuel cells are already proven. Hydrogen could be a fuel substitute and could well be the main element in future energy delivery.
However, there is a trap in something this attractive. For over thirty years, Americans have chosen to stay with fossil fuels based on the promise that something new and better was almost ready to displace the use of fossil fuels. The new and better something never materialized, with the result that fossil-fuel use now is threatening the planet's climate. Is it safe to continue this way, or should we look for other solutions that are available now?
There are two time-frames to consider. With present technology, renewable energy can displace a big part of fossil-fired electric power, but will lose that capability as the backup fossil-fired plants wear out. In the long run, the world must focus on non-fossil energy sources. Unless some form of bulk energy storage is invented, renewable sources will only be able to provide about ten per cent of the energy the US uses. Conservation, if pursued aggressively, could hold energy consumption to its current level.
The next few articles will take a look at nuclear energy.
Tuesday, January 15, 2008
The following information comes from the US Department of Energy, using data from 2005 for US emissions.[source]
The total emissions of CO2 for the US weighed in at 6009 million metric tons. The main contributors that are amenable to replacement are as follows:
|Electricity generation from fossil fuels||2375 MMT|
|Residential use of natural gas||262 MMT|
|Gasoline motor fuel||1171 MMT|
The remaining 2291 MMT is spread over a large range of agricultural, residential, industrial, and transportation applications and miscellaneous applications such as road pavements. Some improvements can be sought here, but most of the users already are economically motivated to reduce energy consumption, so we should only count on modest improvements. Here's a plot that shows where all the greenhouse gases are coming from in the US:[source]
Out of all these, electricity generation is where the greatest savings can be made, accounting for 40% of the total CO2 emissions.Taking CO2 emissions as a whole, there are four options available: carbon sequestration, conservation, renewable energy, and nuclear energy. We'll cover the first two in this article.
1) Carbon Sequestration
It is possible that the CO2 could be captured and stored in some geological formation.
The problems with sequestration are that it's very expensive to pipe the CO2 from the power plant to the formation and pump it deep into the ground, and there's no way to be sure the CO2 will stay there. The scheme du jour is to bubble the gas into saline aquifers and hope the CO2 will form stable minerals there. No one knows what the capacity of the available aquifers is, or how to find out.
Improving energy codes has gone a long way toward reducing greenhouse gases. Americans are using only as much energy per capita as they were ten years ago and twenty years ago. Meanwhile, energy consumption per dollar of domestic product has dropped about 40% since 1980. Of course, the US has shifted away from manufacturing toward importation in that same period, which accounts for some of the savings. Nonetheless, it's clear that energy codes can play a part in greenhouse-gas reduction.[source]
It can be stated with no fear of contradiction that people who live in affluent countries could reduce their energy consumption by large amounts. The problem with this solution is that there is a huge difference between can-do and will-do. People for the most part don't know how to quantify energy consumption. People drive motorhomes and put in compact fluorescent lights to balance their carbon footprints. People live in 8000-square-foot houses but recycle their wine bottles so it's all okay. An energy plan that depends on people giving up their big houses and their flying trips around the world and their motorhomes or boats or personal aircraft needs to be studied carefully.
What happened in the past was that alternative-energy advocates assured everyone that using fossil fuels was perfectly acceptable because new energy sources would meet the world's energy needs and switching over was only a matter of making some simple political decisions. But it turned out that the new energy sources weren't adequate for the task and continuing to use fossil fuels had tragic results.
In the next article we should look at some of those alternative energy sources and see what their limitations are.
Monday, January 14, 2008
In the past, this has led to some unfortunate situations. A few people claiming to have scientific qualifications have made arguments that are demonstrably false. It also led to an embarrassing TV presentation in the UK which claimed that global warming was a conspiracy authored by Prime Minister Thatcher in which scientists lied for pay. The presentation showed falsified solar data, claiming that it matched global temperature history, and warned that Africans would suffer severe deprivation if they were denied fossil-fueled electricity.
Among the skeptics, one of the most important is United States Senator James Inhofe, the ranking Republican member of the U.S. Senate Environment and Public Works Committee. One would predict that Senator Inhofe would examine the subject carefully. Representing an oil-producing state, and being a strong conservative with investments in aviation, the Senator also flies personal aircraft as an avocation. He and his staff have compiled an extraordinary treatise which must include just about every criticism aimed at the process by which the consensus on global warming was formed.
As we look through the arguments, some patterns emerge. The most substantive of the arguments assume that there can only be one cause of global temperature change; since solar activity was clearly the driving force before 1850, they conclude that it still is the sole driving force. This and the other scientific arguments repeat the false arguments mentioned before.
Of the remaining arguments, many contend simply that too much emphasis is put on dubious methodologies: proxy data and computer models. That's reasonable enough, but the compilation leaves out the fact that the proof of climate change doesn't depend on either of these, as shown in our last article.
Some of the critics don't challenge the science but complain about the management of the UN's Intergovernmental Panel on Climate Change. That's important to conspiracy believers but not to people more interested in the actualities.
The last group of critics don't challenge either the science or the politics, but warn that excessive alarmism could lead to mistaken decisions. Implicit in this argument is the contention that CO2's effects on the environment couldn't be very great.
The question here is, what is very great? We've only seen a temperature rise of 0.7°C (1.2°F) in over 150 years. Who cares? You can't even feel that! But mountain glaciers get a little less snow in the winter and melt a little faster in the summer. In time, the glaciers disappear and farmers who depend on snowmelt in the summer don't get it. Semi-arid parts of Africa that got just enough rain to grow some grass for cattle get less and tens of millions of people watch their livelihoods die. Beetles that never could get up a big population before because of winter-kill now can survive and increase gradually in numbers so they can destroy a forest. Cold-water fish don't tolerate temperature change and move to a different part of the ocean, disrupting their reproduction cycles. That's what we're seeing now: small temperature changes have big effects. What will happen as the temperature rises another degree? Or two degrees?
Maybe this is alarmism. If so, then alarmism isn't necessarily a bad thing.
Now that we've covered the evidence for global warming and the arguments against it, the next articles should cover our options for minimizing it.
Saturday, January 12, 2008
First, let's look at the temperature data we have. One set of data comes from NASA [source] and the other is provided by Met Office Hadley Centre for Climate Change in the UK.[source]
The data don't agree exactly because (1) the NASA data shows the deviation from the 1951-1980 average and the Hadley Centre data shows the deviation from the 1961-1990 average and (2) the calculations were done independently so small differences are expected. We should bear in mind that the older data comes from spottier readings and is less reliable. The Hadley Centre data is shown both raw and smoothed. Now we'll look at the different factors that affect global average temperature, comparing them with the smoothed data.
Sunspots receive plenty of mention in the popular literature and we have more data to look at.[source]
This is promising. Notice that the sunspots are lower in number, almost zero, in the period 1650-1700. There is anecdotal evidence that Europe and China were cooler then.[source] There also is anecdotal evidence of the same thing happening in the early 19th Century[source], although the Tambora volcano could have contributed.
Looking more closely, we see that the low number of sunspots around 1900 fits the lower temperature then, and temperature and sunspot-count both rise thereafter. There was more activity around 1960 that shows up as a temperature bump, and also around 1980-1990, that fits with a slight, stretched-out bump. So it seems clear that sunspot activity affects global temperature. Or, possibly, sunspots affect the irradiance and it's the combination that affects global average temperature. A suggestion under review is that solar activity diminishes cloud formation by influencing the intensity of cosmic rays, as shown in this figure:[source]
On the other hand, the temperature bumps are small compared with the upward temperature trend since 1900. Furthermore, if solar activity was the main driving force, then average temperature should drop after 1990 but instead it keeps going up. That means something else has become a stronger driving force since 1900.
Solar irradiance is the intensity of solar energy striking the earth and its atmosphere in watts/sq meter. It seems to follow sunspot activity, which seems reasonable. But it only matches the temperature changes about as well. [source]
The gas emissions from natural vegetation are an important part of the atmosphere's loading, but the amount of land devoted to it hasn't increased. It's possible that emissions have risen as a result of global warming. Either way, natural vegetation can't be blamed for the temperature rise since 1900.
Volcanoes emit gases, too. We can do a quick calculation that shows volcanoes could never affect the atmosphere's CO2 concentration.
Volcanoes also emit particulates and aerosols, which reflect heat away from the earth and cause more clouds to form, causing further cooling. Data from the Mauna Loa Observatory shows the effects of volcanos since 1958.[source]
We can see that volcanoes reduced solar transmission in 1982 and 1991, but they don't affect the global-average temperature rise by much. The conclusion is that volcanoes don't affect global warming either way.
One way the Earth's core could heat the oceans is by undersea volcanoes. We can do a quick calculation that it would take around a half-million undersea volcanoes equal in size to the one at Mount Saint Helens in 1980 every year to account for the warming the oceans have seen since 1955. Even if the calculations are off by a factor of ten, it would take around five thousand such volcanoes every year just to account for ten per cent of the warming. And, there would have to have been no volcanoes before 1910. So undersea volcanoes aren't a major factor.
Another possibility is the extrusion of magma into the oceans at the edges of separating tectonic plates. But the USGS has found that the rate tectonic plates have been moving hasn't changed in the last thirty years from what it's always been.[source] So magma doesn't explain the recent warmup.
As is the case for natural particulates and aerosols, artificial particulates and aerosols have a cooling effect by reflecting sunlight and by causing clouds to form. The temperature graph shows a sharp drop around 1940 until almost 1950, then a slow rise until 1980 or so, and after that a sharp rise. That fits with our expectations: industrial production increased radically during the war. Virtually no attention was paid to the resulting pollution. The postwar period experienced some relaxation in both production and pollution. About 1970, serious efforts were started to control particulate emissions from fossil-burning power plants, and the temperature graph clearly shows that global warming accelerated.
There are a lot of these that can be important: carbon dioxide, methane, and nitrous oxide are the most dominant. We need to consider their emission rates in order to compare their relative importance in the changing of the global average temperature.
The US Department of Energy has estimated their yearly emission rates and ranks them this way (2005 data [source]). Global data comes from IPCC's report for 2001[source]. All the rates are in million metric tons per year. These numbers are calculated, but show more precision than they should. Nonetheless, they show relative magnitudes.
|US||US (CO2 Equiv)||World||World (CO2 Equiv)|
Clearly, CO2 is the most important artificial greenhouse gas in respect to changing temperature. The present CO2 content of the atmosphere is 3,036,000 MMT, so the emissions amount to almost 1% of what's presently in the atmosphere. The CO2 concentration is rising roughly 0.5% per year, so about half is staying in the atmosphere and the other half is going somewhere else, mostly into the ocean. We have some measured CO2 concentration data taken from ice cores.[source]
This is our smoking gun. The CO2 concentration has risen from less than 300 parts per million all the way up to 383 ppm in 2007. Of all the factors affecting global average temperature, it's the only one that's been increasing since 1980, so it's the only one that can explain the temperature rise during that time.
What is especially troubling is that, before 1850, CO2 concentration has not exceeded 290 ppm in over 400,000 years.[source]
That's not to say that we can ignore the other greenhouse gases, but controlling CO2 emissions is essential to limiting global warming.
The evidence shows that solar activity and aerosols can influence global temperature. Before 1900, when greenhouse-gas concentrations were below 300 ppm, solar activity seems to have been the main driving force. Since then, greenhouse gases have become the main driving force.