Tuesday, March 26, 2013

Energy Risks and Rewards

Part I Fossil Fuels Rewards and Risks

Energy is transformative for human society. Energy inputs have transformed the way of life of high energy societies. During the middle ages, low energy input was associated with great poverty and a few wealthy persons who commanded the labor of other people as an energy source. Natural energy sources such as windmills and the use of the sun for drying food and clothing did not bring people out of poverty.

In Holland, wind driven pumps kept the sea from overwhelming land that was under sea level. Dikes kept the sea out. In many countries, windmills were used to grind grain. Water powered mills were also used to grind grain. Wind was also used to power ships. Sunlight was used to dry food and cloths. In addition to these natural energy sources many countries began to use coal for heating and cooking. In the eighteenth century, James Watt discovered how to build efficient steam engines that were powered by coal. This began the Industrial Revolution. The energy produced by Watt's steam engines was harnessed by increasingly sophisticated technology that was used to pump water out of mines, to drive ships previously driven by sails and to drive mobile transportation in the form of railroads. In addition, the energy was captured by factories that began to produce useful items in large number, for example weaving cloth. Since energy harnessed from coal was replacing human labor, reliance on coal increased the wealth of society as less and less labor was required to produce more and more goods.

At the beginning of the twentieth century it was discovered that crude oil could be processed to produce   fuel for automobiles, farm implements and eventually railroad trains. Oil based fuels could be used to power ships. The advantage of oil over coal was that it took less labor to produce and use oil rather than coal. Industrial use of coal began to decline.  Oil products began to replace coal as a source of energy for factories and heat for homes and commercial structures. Oil recovery led to the production of large amounts of natural gas which is flammable gas. At first the natural gas was burned off, but then it was discovered that natural gas was an excellent replacement for coal and oil products in the home. Natural gas could be used for heating, cooking, and heating water.

The use of coal, oil, and natural gas have produced a revolution in human way of life. Workers who's ancestors a few generations ago performed unskilled labor in fields all of their lives, are now performing jobs that require high skill levels. The advances in human skills have been so great that tools that we now use have great power, but require very little energy input in their manufacture. There are still technologies that will not easily be replaced that rely on fossil fuels. In particular, oil and oil products are likely be required by the air industry for some time to come because no viable technology exists to meet the energy of flight.

The use of fossil fuels during the last three centuries has produced revolutions in human life, but there is a risk. Ultimately the risk must be addressed. At one time it was believed, by some, that the fossil fuel supply was so limited that we would run out of it by 2050. This is no longer the case. New technologies have emerged during the last decade that have increased the reserve of natural gas and oil. It seems unlikely that we will run out of fossil fuels over a period of time of at least a hundred years. This would be good news were it not for the fly in the fossil fuel ointment. The carbon dioxide pollution and it's climate consequences.

Scientists have postulated for well over a hundred years, that the release of carbon dioxide and other green house gases associated with the fossil fuel industries will lead to an increase to what is called the "Greenhouse Effect" on the atmosphere. Carbon dioxide tends to trap energy from solar radiation inside the atmosphere. This in turn increases energy trapped in the atmosphere and in the seas. Scientists are not quite sure how this trapping of energy will effect human life. Some are concerned primarily with the warming effect of green house gases while others foresee increasingly powerful weather events. The sort of weather events that concern scientists are very large rain storms, tornadoes, and powerful hurricanes.

During the last four years, the city of Nashville was devastated by what atmospheric scientists described as a thousand year weather event. An extremely large and powerful rain storm that extended from central Kentucky through the Nashville basin on to the Tennessee River west of Nashville. There was very considerable flooding in Nashville as a result of this weather event. There had been a similar event in Atlanta the previous year. Weather scientists calculated that the Nashville event was a once in every thousand year event, but the Atlanta event was a once in every ten thousand year event.

We are witnessing in the twenty-first century an increasing number of catastrophic weather events. I heard all of this foretold at Oak Ridge National Laboratories, ORNL, in the spring of 1971. There are those who claim that even if carbon dioxide is having a greenhouse effect, that the claim, that this is catastrophic, is to make one an alarmist. The warnings about alarmist discount the risks that we face even if there is a probability that climate will not change and that weather events are not indicators of things not getting worse, there is a risk that things will get worse. I am calling attention to the risks; to the dangers we face. Anyone who dismisses what I say as alarmist is simply being dishonest.

Insurance companies know that our risks are real and the consequences of greenhouse gases have arrived. They look at the bills they face for events like Hurricane Sandy, an unusual weather event, that is costing the insurance industry billions of dollars and shake their heads at the global warming skeptics. We simply have no choice but to think about replacing fossil fuels with other energy sources. The costs of failing to do so will eventually become unacceptable. We need a plan to do this and we need to begin the plan quickly. The risks of continuing down the path we are following now is too high.

In addition to global climate change engendered by carbon dioxide released by fossil fuel related technologies, there are other significant risks from the fossil fuel industry. Extraction of fossil fuels carries with it a significant risk to human life and human health. The coal mining industry still looses thirty thousand lives every year world wide. The Gulf oil drilling disaster of two years ago killed eleven workers. In addition, it caused billions of dollars of damage to wildlife and the deep sea environment of the Gulf of Mexico as well as creating economic costs running into the billions of dollars with respect to economic use of the Gulf area for recreation, tourism, for fishing and other activities contributing to the local economy.

Oil and natural gas pipeline explosions have injured and killed people as well as damaging property. Gas fired power plants have exploded killing and injuring workers. Natural gas explosions in the home are consequences of heating, cooking and other uses of natural gas in the home. Byproducts are carcinogenic and are sometimes released in urban areas. Burning coal releases different pollutants which kill an estimated fife hundred thousand people world wide each year. In addition, burning coal releases radioactive materials that are embedded in the coal. Burning natural gas also releases radioactive gases and materials into the environment. The adverse human and environmental consequences of fossil fuel use are risks that must be weighed against their benefits.

Part II Green Energy Risks and Rewards

If fossil fuels are unacceptable, some people think that we should revert to earlier energy sources: water, wind, and sunlight to replace fossil fuels. There is little doubt that energy can be produced through the use of wind, water, and sunshine, however it is not clear that wind, water, and sunshine will produce all of the energy we need when we want it or to produce the energy so reliably as to meet the needs of society. Among the advantages of fossil fuels, is their relative flexibility. In comparison, natural energy sources are to a certain extent predictable, but not dependable. The sun usually shines in the daytime, but not at night. The sun will shine almost 100% of the time in the desert Southwest while in East Tennessee where I live, the sun cannot be depended on to shine many days of the calendar year. Furthermore, many other days are partially cloudy. This makes East Tennessee a poor candidate for solar energy.

On the Northern Great Plains wind powered generators will produce between forty and fifty percent of their rated capacity.  Meanwhile, in East Tennessee where I live, we may be lucky if local wind generators produce ten percent of their rated generating capacity during the month of August, thus, East Tennessee is not a good candidate for green energy. When this fact was brought to the attention of self styled Greens they suggested that we cut down our trees and burn them for energy. That is, we use Iron Age technology. Of course East Tennesseans are green to the extent of loving their native forests and would prefer not to cut them down for energy related purposes. The Greens will tell us, of course, that we all have to make sacrifices at which point we have to say: "Whoa, wait a minute, what does it mean to be green? Doesn't being green mean protecting nature and the environment; our environment, including our forests?!" This seems to be a case of "in order to save the village, we had to destroy the village". So, we are left with the choice of destroying nature in order to protect nature or alternatively continuing to use fossil fuels as a means of "backing up" green energy.

The Green solution simply does not offer us a solution for solving the carbon dioxide problem, at best it may offer us a means of partly mitigating the carbon dioxide problem. We would have to ask the Greens themselves why they find nuclear energy so unacceptable, in fact many Greens have reached the pro-nuclear conclusion as the only solution consistent with Green values. At the outset, there is no risk involved in Green energy as a solution to carbon dioxide dumping into the atmosphere. At best, the green solution would mean a little less carbon dioxide would go into the atmosphere. This is what the pro-nuclear Greens themselves have concluded and explains why they accept the necessity of nuclear power.

The risks entailed by Green energy are of a different nature.  Wind generators are not entirely safe. Workmen fall off them repairing problem parts. A fall from a wind generator is going to be fatal. Wind generators can be toppled by tornadoes and other strong winds. Sea based wind generators might be vulnerable to large storms. Dust storms can affect solar electrical generating facilities. Solar PV cells can get dirty over time due to dust and other materials in precipitation. This dirt on solar cells in turn impairs their efficiency so that they gradually loose generating capacity. Cleaning solar PV cells that are placed on the roof involves danger as cleaners may fall off the roofs where the cells are placed. Fire departments have identified solar PV cells as a risk for firefighters. The cells generate electricity and firefighters on building roofs fighting fires may be shocked by contact with solar PV installations. Concentrated solar installations also require considerable cleaning which in turn requires a lot of water. They also use water to remove heat from mirrors and other parts of the installation and to operate steam turbines as part of the electrical generation process. Other technologies are possible, but,at the end of the day, desert placed concentrated solar installations require a considerable amount of water.

While desert based concentrated solar installations may be safer than urban rooftop PV installations, they are very limited by geography. Thus desert placed concentrated solar installations compete with other industries, with farmers, and with urban dwellers for the very limited amount of water that is available in the desert. To maximize the solar generating potential of desert areas the human use of those areas for other purposes may be excluded and we are left with little choice except to evacuate the human population since no water would be available for other purposes.

Green energy schemes that are based on natural areas where green energy is likely to be produced require the transmission of electricity from the electrical production facilities to consumers. This requires the building of large and long transmission lines and the creation of a continent wide grid. Even with these transmission lines, the supply of electricity would clearly be inadequate and unreliable. Energy storage facilities would have to be added in order to increase the reliability of any natural electrical generation scheme.  These facilities would be quite expensive if the goal is to produce 100% of the nation's electricity.

There were extensive discussions of these problems in Berry Brook's Blog BraveNewClimate a few years ago. Anti-nuclear Greens offered defenses and were trounced by supporters of nuclear power in these discussions. The approach of anti-nuclear Greens is to simply ignore BraveNewClimate papers and discussions on the problems with green energy and continue their loyalty to green energy as if a green solution to the carbon problem were possible. I have argued in Nuclear Green Revolution repeatedly that the green solution is not green and not a solution. Although I would not claim to be on the same stature as Berry Brook, I would claim that my arguments have been respectable.  I did offer critique to works of individuals such as Mark Jacobson. Jacobson has never responded to my criticisms although he did offer a complaint to the inclusion of one of his pictures in one of my posts. I removed the picture, but Jacobson did not offer any defense of his own work.

I also offered numerous criticisms of Amory Lovings. The work of Amory Lovings has been criticized by many energy writers and by many supporters of nuclear power. Lovings has responded frequently by ignoring the criticism; occasionally by promising a response that would never be delivered on or by offering a partial response. Lovings titles himself as the chief scientist of the Rocky Mountain Institute, but real scientists defend themselves from criticism and, indeed, their professional stature stand or fall on their willingness to respond to criticism.

We are forced to conclude that there is no risk with green energy. Green energy has been rejected in the past and will continue to prove unsatisfactory in the future. We simply cannot power a Post Industrial civilization with green energy.

Part III The Complexities of Nuclear Risks and Their Rewards

Critics of nuclear power often conceive of all reactor types as carrying the same risks. This is not, in fact, the case. The topic of reactor risks contains many complexities. During World War II, Manhattan Project scientists noted that many different reactor types were feasible and that they might not all carry the same risks and rewards. The Pressurized Water Reactor, the most common sort of reactor, is inherently dangerous because it's design requires running a large amount of water through the reactor core. The heat from the reactor when it contacts water creates complex safety issues. These issues lead to major design features of Light Water Reactors that are intended to allow for safe operations of water cooled reactors. Engineers who design this sort of reactor take safety risks. These are calculated risks and depend on design, material quality, and operator training to assure reactor safety. Since 1954 the United States Navy has operated hundreds of water cooled reactors in submarines and in surface ships. None of these reactors has undergone a major accident. Their safety is dependent on the quality of their design, the qualities of the materials from which they are built and the expert training of their operators.

The United States Navy's experience with water cooled reactors suggest that safety is the norm and that reactor accidents are at worse rare exceptions. Major accidents have occurred in early water cooled reactors. In particular in the Three Mile Island and the three reactors at Fukushima Daiichi. The Three Mile Island accident was the result of both design and operator errors. The more recent Japanese reactor accidents were the result of unanticipated natural events. None of these accidents produced reactor related deaths although they did include substantial release of radioactive materials. From a rational view point even the early designs of the Three Mile Island and the Japanese reactor power plants were safer than any green energy solution except for perhaps concentrated solar generation a technology that is confined to desert areas.

The Light Water Reactor gives us evidence that some reactors entail risks because of risky features in their design. Another such reactor would be a sodium cooled reactor such as the Integral Fast Reactor because sodium poses handling difficulties, which, if not overcome, can lead to highly dangerous consequences. Such an event would probably be very rare and should not be considered a major reason for failure to consider the use of sodium cooled reactors.

Molten Salt Reactor technology does not offer a path to the future with a hundred percent assurity, but it does seem to offer a path worthy of exploration. A path that might well lead us to a high energy tomorrow. Graphite reactors, whether cooled by gas or by molten salts are highly safe. I offered a number of discussions about the safety of graphite reactors in previous posts on Nuclear Green. My conclusion was that graphite is a highly safe material which tends to impede rather than promote accidents. Finally, Molten Salt Reactors offer few risks. They are chemically stable and operate at a one atmosphere pressure making explosions not just unlikely, but impossible. Molten salts are not flammable and can be used to facilitate safety systems that are largely controlled by the laws of nature rather than by technical interventions. The engineering required to make water cooled reactors safe increases their costs, but since Molten Salt Reactors do not require the same technical interventions in order to maintain safety they are likely to cost less than water cooled reactors.

1 comment:

monowar hossain said...

Greate!The Nuclear Green Revolution Energy Risks and Rewards


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