Replacing Fossil Fuels

Discussion in 'Politics' started by FRE, Jun 22, 2010.

  1. FRE

    FRE
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    REPLACING FOSSIL FUELS
    21jun2010

    INTRODUCTION

    Although this paper has been written primarily to deal with energy concerns in the United States of America, much of the information will be useful for other countries also.

    Regardless of whether we are concerned about global warming, we know that burning fossil fuels damages the environment and causes health problems. Therefore, we should be working diligently to develop alternative energy sources to end our dependence on fossil fuels.

    The proposed alternatives to fossil fuels include wind energy, solar energy, and nuclear energy. Hydroelectric power is also useful, but I am excluding that because we have already developed practically all of our available hydroelectric sites here in the United States. When considering alterative sources of energy, we should also consider what would be practical in countries outside of the United States since sources of power which would be practical in the United States may not be practical elsewhere.

    To be able to understand adequately the challenges of developing alternative sources of energy, we must have an adequate understanding of how our current sources of energy operate. Accordingly, I shall begin by explaining some of the operational details of coal, gas, hydroelectric, and nuclear power plants. After that, I will explain the advantages and disadvantages of wind and solar power. That will facilitate a better understanding of the challenges of integrating wind and solar power with the existing sources of power. Then, I will explain why nuclear power is probably the only source of energy that can economically and reliably provide the large amounts of power required by an industrialized world. Last, I shall address the problems of eliminating the use of petroleum to power our transportation system.
     
  2. FRE

    FRE
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    CURRENT SOURCES OF ELECTRICITY
    21JUN2010

    Currently, we get about 10% of our electricity from hydropower, 20% from nuclear power, 20% from natural gas, and 50% from coal. Although that adds up to 100%, we do get very small amounts from other sources.

    The demand for energy is constantly fluctuating according to the time of day, day of the week, season, and weather. For example, during the summer, the peak load occurs early in the afternoon because of the operation of air conditioning systems. On weekends, when many businesses and offices are closed, there is less demand for power. Because there currently is no provision to store electrical power, the various sources of power have to be adjusted constantly so that the supply exactly equals the demand. Doing so is quite challenging, especially if demand changes quickly.

    Power companies in some areas can, to a certain degree, control the demand for power. For example, in Albuquerque NM, U.S.A., they have the capability to shut of some air conditioners if the demand for power temporarily exceeds the supply.

    Most coal burning and nuclear power plants are designed as base load plants, i.e., they are designed to run at 100% capacity at all times. Their output cannot be frequently changed without greatly shortening the life of the equipment.

    Some coal burning, natural gas burning, and nuclear power plants are designed as load following plants, i.e., their output can be continuously, although very slowly, adjusted as the demand for power changes. However, they are most efficient when operating at full power and continually changing output does shorten the life of the equipment.

    Peaking plants are gas turbines which are similar to aircraft jet engines. They are the least efficient power plants and costly to operate. For peaking plants, the cost of the fuel is a major expense, so power companies prefer to operate them as little as possible. However, they can change output quickly when there are sudden changes in the demand for power.

    Some small countries depend heavily on Diesel power plants. Unfortunately, Diesel power plants are expensive to operate but they do have advantages: 1) They are available in small sizes, and 2) their output can be quickly adjusted to meet sudden changes in the demand for power.

    The output of hydroelectric generators can be changed quickly without affecting the life of the equipment. However, when they are not run at full capacity, the investment is not fully utilized.

    Spinning reserve consists of sources of power the output of which can be quickly changed as the demand for power varies. It is provided by power plants that are operating at only part load. With the exception of hydroelectric plants, having a considerable amount of spinning reserve greatly increases fuel consumption. It also reduces return on the investment because the facilities are not being fully utilized. Therefore, grid operators prefer to keep spinning reserve as low as possible and minimize their reserve capacity.

    When there are intermittent sources of power connected to the grid, the amount of spinning reserve has to be increased to allow for changes in the amount of intermittent power available. That, of course, results in reducing the efficiency of the fossil fuel power plants which are not running at full capacity and requires that inefficient peaking plants be kept on line.

    Generally, the main cost of generating electricity is not in the fuel; Diesel plants used in small countries may be an exception. Although the cost of the fuel varies depending on whether it is natural gas, coal, or nuclear, in general it is only from 10% to 20% of the cost of generating electricity. For nuclear power, the cost of the nuclear fuel is only about 5% of the cost of generating electricity. However, for peaking plants, the cost of gas is a major operational expense, so peaking plants are used as little as possible. The rest of the cost is in the required return on the investment, labor, and other operating expenses, including the expenses of distributing the power. Thus, if an alternative source of power is connected to the grid thereby reducing the amount of power provided by the existing utility companies, the overall cost seen by the utility companies is affected very little, with the exception of Diesel plants. If the alternative source of power varies rapidly and greatly, then utility companies have to operate their peaking plants to compensate for the rapid changes, and peaking plants are very expensive to operate.

    Now that we have a basic understanding of the challenges of continually adjusting the power provided to meet the demand exactly, we will be better able to understand the challenges of integrating alternative sources of power into the grid. Without that understanding, the challenges of utilizing alternative sources of energy could not be adequately understood.
     
  3. FRE

    FRE
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    WIND POWER
    21jun2010

    By now, most of us have seen wind farms with wind turbines slowly turning while generating power from the wind. Without carefully examining the details, it would seem that wind is a wonderful source of power; it generates power without burning fuel and generates no pollution. But, as others have said, the devil is in the details. So, let us examine some of the devilish details.

    We know that the wind does not always blow and that wind generators cannot generate power when the wind is not blowing. So, what happens when the wind stops blowing?

    For days or weeks, the wind velocity can be too low to generate adequate power. In fact, wind generators over the long term generate only about 20% to 30% of the power they would generate if the wind were blowing continuously. We cannot simply stop using power when the wind stops blowing, so there are basically three choices:

    1. Have widely scattered wind farms interconnected.
    2. Store power so that we can use the stored power when the wind stops blowing.
    3. Switch to other sources of power when the wind stops blowing.

    Some may argue that if there are enough wind farms, when the wind is not blowing in one place it will be blowing in another place so we would always have wind power available. It is very easy to make statements without data to back them up. I know of no studies which support the idea that interconnecting widely scattered wind farms would guarantee a reliable source of power. Surely it would be unwise to spend billions of dollars on the unverified assumption that the wind could provide steady power.

    Some argue that power can be stored for use when the wind is not blowing. However, the technology does not exist to do that at an acceptable cost. Pumped storage has been suggested. That can work well, though at considerable cost, but it requires two huge reservoirs at greatly different heights. Thus, pumped storage can be utilized only in a few geographic areas. Using rechargeable batteries is far too expensive. Compressing air into natural underground caverns would work in theory, but it is very expensive.

    We could also revert to fossil fuels when the wind is not blowing. However, that means that wind generators would be built IN ADDITION to fossil fuel plants, rather than INSTEAD of fossil fuel plants, thereby greatly increasing the cost of power.

    It’s also not clear that wind generators would actually reduce the amount of fossil fuel burned. Because the wind velocity is constantly changing, even when the wind is blowing utility companies would have to maintain enough spinning reserve to compensate for the constantly changing wind velocity. Because spinning reserve is fuel inefficient, it may be that even when the wind is blowing the amount of fossil fuel burned would not be reduced. Experience in Europe has shown that there are serious problems when wind generated power exceeds 20% of the total power generated.

    Another problem is that the existing grid has been set up to accept power only from existing power plants. Extending and modifying the grid to accept power from widely scattered wind farms would be an enormous expense. The cost of installing wind generators, apart form extending the grid, has been roughly determined, but the problems associated with wind power are so enormous that there is little point in even examining the cost of the wind generators.

    For each megawatt of capacity, wind power requires approximately 460 tons of steel and 870 cubic meters of concrete. By comparison, coal power requires 98 tons of steel and 160 cubic meters of concrete while nuclear power requires 40 tons of steel and 190 cubic meters of concrete.

    Even with these problems, wind power does have a rôle to play. Some people live in places so remote that connecting to the grid would be impractical. If solar power is impractical because the weather is frequently cloudy, wind power with battery storage and a small Diesel generator for back-up power may be a good choice. Also, in small countries with hydro power, wind generators can reduce the amount of water used by the hydro system thereby reducing the need to burn fossil fuels when the water runs low. But as a major source of power for a large country, wind power is not practical.
     
  4. FRE

    FRE
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    SOLAR POWER
    21jun2010

    There are two basic types of solar power: Photovoltaic panels, and solar thermal electric. The type of solar power with which most people are familiar is photovoltaic panels (PV panels). Like wind power, solar power is also intermittent, but it is much more predictable and much less subject to the sudden variations in output that make wind power exceedingly difficult to integrate into the grid.

    PV PANELS

    PV panels can easily be installed on roof tops or almost any place where there is adequate sun and where they won’t be in the way, subject to damage, or create environmental problems. They also have the advantage of being effective when power is most in demand, i.e., in the early afternoon when the air conditioning load is high. However, they are not without problems.

    Although the power output from PV panels is more predictable than the power output from wind generators, they still do not provide continuous power. Even so, many people find that they come out ahead by installing PV panels on their roofs. Let us see how this is possible.

    Installing PV panels is encouraged by heavy subsidies and by requiring power companies to buy power from PV panel owners when the PV panels produce more power than the owner is using. If there were no subsidies and if power companies were not required to buy excess power from the PV panel owners, then the PV panels could not be economically justified; the interest on the installation would exceed the amount saved on the power bill.

    As we have seen in the chapter “Current Sources of Electricity,” the cost of fossil fuel to generate electricity is only about 10% to 20% of the cost, with the possible exception of Diesel power. Therefore, when surplus PV power is sent to the grid, the saving to the power company is very small. In fact, the saving is less than they are required to pay the owners of the PV panels. And, because of the intermittent nature of PV power, power companies still have to maintain as much generating capacity as if there were no PV panels. So, although PV panels can reduce the amount of fossil fuel burned, they can never eliminate the burning of fossil fuel.

    PV panels generally have a useful life of from 20 to 30 years after which they have to be replaced. Unfortunately, current PV panels contain toxic materials which complicate recycling.

    Recently, California senator Diane Feinstein opposed a large PV panel project in the Mojave Desert of California; it would have required 70 square miles and she deemed it environmentally unacceptable. Also, the water required to wash the dust off of such a large collecting area would also have been a problem when the scarcity of water in desert areas is considered.

    Even with the limitation of PV panels, they are still quite useful where connecting to the grid is not practical. In third world countries, they are used to provide power to pump water in which case the intermittent availability of power can easily be worked around. They are also used to power school crossing signals which require very little power. However, because of the huge area they require and because of the intermittent nature of the power provided, they are not suitable as a major source of power for a country with high energy needs. That is especially true of countries with a high population density, such as China and India, and countries where the weather is often cloudy.

    SOLAR THERMAL ELECTRIC POWER

    Solar thermal electric power can be more practical than PV power. Solar thermal electric plants use heat from the sun to boil water and drive turbines. There are two basic types: the trough type, and the power tower type. The trough type uses long trough-shaped reflectors which concentrate heat from the sun onto long pipes which contain a fluid which is used to boil water to generate steam. The power tower type uses a field full of mirrors which, using electronic controls, track the sun to direct heat onto the top of a tower which collects the heat. With either type, excess heat can be used to heat tanks containing a fused mixture of potassium nitrate and sodium nitrate to store heat so that power can be generated when the sun is not shining. However, there is no guarantee that enough heat can be stored so that power can be generated if the weather is cloudy for several days in a row. Therefore, even solar thermal electric power cannot replace other sources of power unless the risk of being without power is acceptable.

    Because the power tower type can generate higher temperatures, it is more efficient than the trough type. The greater efficiency means that for the same power, less collector area is required, the steam turbines can be smaller, and the condensers require less cooling water.

    Regardless of the type of solar power used, huge land areas are required to generate sufficient power. Environmental groups would be certain to object to any installation in areas which they consider to be environmentally important. Also, because power would be generated where the grid is not designed to accept it, very costly changes to the grid would be required to utilize solar power.
     
  5. FRE

    FRE
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    NUCLEAR POWER
    21jun2010

    INTRODUCTION

    There are many possible designs for nuclear reactors and many possible fuel cycles; that may not be obvious from the popular media. Therefore many people are not aware of the multiplicity of available designs and fuel cycles. Nuclear reactors have even been designed that use thorium for fuel instead of uranium and at least one thorium reactor has been successfully tested.

    I cannot cover all possible designs of nuclear reactors and all possible fuel cycles. Doing so would require thousands of pages. Moreover, it would also require considerably more knowledge than I have. Therefore, I have written only enough to provide an extremely basic understanding of a few types of reactors.

    In 1954, Lewis L. Strauss stated in a speech that eventually electricity would be too cheap to meter. That statement has been used for decades to ridicule proponents of nuclear power. However, that statement has been taken out of context. No one qualified in the field of nuclear power has ever believed that nuclear power would be to cheap to meter. Moreover, the distribution costs alone are a major portion of the cost of electricity. However, especially when considering externalities, nuclear power probably is already cheaper than power generated from coal and is likely to become even cheaper as progress continues.

    MOST COMMON REACTOR TYPE (PWR)

    Currently the most common reactor type is the pressurized water reactor (PWR). Here in the U.S., our approximately 100 PWRs generate 20% of our electricity.

    Natural uranium contains 0.7% U235 with the rest being U238. Unfortunately, our PWRs cannot operate on natural uranium; they require uranium which has been enriched to approximately 5% U235. The enrichment process requires removing enough U238 from natural uranium so that what is left is 5% U235 and 95% U238 with the excess U238 being treated as waste, a process which is very costly. In addition, when enrichment process is extended, it can enrich uramium to the 90% U235 which is required for nuclear weapons. Thus, PWRs can create the risk of nuclear weapon proliferation.

    Also, PWRs create significant waste and the amount of waste is increased by the material used to make the fuel rods. However, most of the waste consists of unused fuel which, by reprocessing, can be removed and reused, thereby greatly reducing the actual amount of waste. Although France and some other countries are reprocessing nuclear waste, we are not doing so here in the U.S.

    PWRs also require a large pressure vessel which is commonly about 15 feet in diameter. To keep the water in it in liquid state at high temperatures, a pressure of about 2500 psi must be maintained. To prevent corrosion, the vessel must be made of stainless steel. Thus, the pressure vessel is extremely expensive and represents a significant portion of the cost of a nuclear power plant.

    In spite of their problems, PWRs are capable of providing safe, reliable, and economical power. Power plants using PWRs have an anticipated useful life of from 40 to 60 years. Thus, they will be around for a long time. Also, we can expect that more will be built until they are superceded by other reactor designs.

    The matter of escalating costs of PWRs has been raised. A major factor in the cost is licensing delays resulting from changes in safety requirements after the license to begin construction has been issued and construction is either complete or almost complete. The lack of a unified design has also contributed to escalating costs. These problems can be eliminated thereby significantly reducing the cost of nuclear power.

    CANADIAN DEUTERIUM URANIUM REACTORS (CANDU)

    CANDU reactors have advantages over PWRs:

    1. They can use natural unenriched uranium as fuel thereby reducing operating costs and reducing the risk of nuclear weapon proliferation.
    2. They do not require a large pressure vessel.
    3. They produce less nuclear waste
    4. They are capable of using, as fuel, the waste from PWRs.

    Many CANDU reactors are used for power generation in Canada and some are exported to other countries, to the benefit of the economy of Canada. However, even though they have a good safety records, they are not licensed for use in the U.S.

    LIQUID FLUORIDE THORIUM REACTORS (LFTR, PRONOUNCED “LIFTER”)

    The LFTR was originally designed to power military airplanes but, at least partly because of the development of missiles, was never used for that purpose. However, at least one LFTR was built and successfully tested.

    The fuel for a LFTR is thorium tetrafluoride, a salt which is a crystaline solid at room temperature and a liquid at the temperatures at which reactors operate. Among the advantages of the LFTR are the following:

    1. Because the fuel is a liquid, a meltdown is impossible.
    2. Because the fuel is a liquid, no additional coolant liquid is needed.
    3. Because the fuel is a liquid, fuel reprocessing can be done continuously.
    4. Because a LFTR can operate at very high temperatures, thermal efficiency is high.
    5. The risk of nuclear weapon proliferation is virtually eliminated.
    6. The cost of fabricating fuel into rods is eliminated.
    7. A LFTR need not be shut down for refueling.
    8. There is much less waste, and the waste decays to a safe level within 500 years.
    9. Thorium is about four times as abundant as uranium.
    10. No expensive pressure vessel is required.
    11. If overheating occurs, the reactor will automatically shut down.
    12. A LFTR can burn existing nuclear waste as fuel.
    13. The projected cost of LFTRs is significantly less than the cost of PWRs.
    14. The LFTR has a totally fool-proof shut down method.

    The reactor vessel itself is nothing more than a vessel designed to contain the fuel, i.e., molten thorium tetrafluoride. In the bottom of the vessel is a drain which, during operation, is plugged by frozen fuel. The plug is kept frozen by circulating a coolant around it. When the coolant flow is stopped, the plug melts causing the fuel to drain into a holding tank configured so that there cannot be a critical mass. Thus, in case of a malfunction, the reactor can be shut down simply by stopping the coolant flow to the plug. No emergency cooling system is required.

    Over the last several years, the awareness of the economic and safety advantages of LFTRs has become more widespread. Their advantages over other reactor types is sufficient that it is likely that eventually they will become the predominate reactor type where moderate to large amounts of power must be generated.

    SMALL MAINTENANCE-FREE NUCLEAR REACTORS

    In some small countries and in remote areas, there is a need for small maintenance-free nuclear reactors. Accordingly, work is being done to develop them. They would be designed to run, without refueling, for about thirty years after which they would be exchanged by the manufacturer for new reactors. They would provide small countries and remote areas with a badly needed source of economical and reliable electricity and would greatly enhance the quality of life for the people living in those areas.

    With reasonably priced electricity available, cooking with electricity would become economical thereby eliminating the need to cut down trees for firewood or import fuel. Electric lights would be a big improvement over fuel-burning lights. Electricity for refrigerators would improve the quality of food available. It would also keep medications and vaccines from spoiling.
     
  6. FRE

    FRE
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    VEHICLE POWER
    21jun2010

    Economical nuclear power could be used to eliminate the need for fossil fuels to power vehicles. There are two ways in which this could be done:

    1. Use nuclear-generated electricity to recharge battery electric vehicles.
    2. Use nuclear energy to manufacture fuel which could be burned in conventional engines.

    Battery electric vehicles are already practical except for long distance trips. The problem of long distance trips could be solved by advanced battery technology or battery exchange systems. Also, we can expect (hope?) battery costs to come down as production increases and production techniques are refined.

    Nuclear power could be used to make either ammonia or dimethyl ether to be used as vehicle engine fuel. Both can be liquefied at readily available pressures, so an adequate quantity could be stored in a vehicle tank. However, a conventional gasoline engine cannot be converted to run well on ammonia, but an engine designed from the ground up to run on ammonia could work well. The fact that ammonia is toxic is also a disadvantage.

    Like ammonia, dimethyl ether can be liquefied at readily available pressures. Engines can easily be converted to run on it and unlike ammonia, it is not very toxic. However, it does contain carbon so, for it to be carbon neutral, a the carbon used to manufacture it would have to be extracted from the air or from some other carbon source other than a fossil fuel.

    In any case, it is essential for us to transition away from using fossil fuels to power vehicles.
     
  7. FRE

    FRE
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    CONCLUSION
    21jun2010

    As we have seen, there are alternatives to using fossil fuels. Probably it will be much easier to eliminate the use of coal than to eliminate the use of petroleum because the most obvious replacement for coal power plants is nuclear power plants. Even if we continue to use uranium for nuclear power plants, we would be better off generating power with nuclear plants instead of coal plants. However, the development of lithium fluoride thorium reactors (LFTRs) can make nuclear power even more attractive.

    Eliminating the use of petroleum to fuel vehicles will probably be more difficult, at least in part because of the extremely large number of vehicles. Currently limited battery capacity and high battery prices, although not making battery electric vehicles totally impractical, are challenging. Using nuclear power to manufacture artificial motor fuels may turn out to be a better path away from petroleum, or the technologies may coexist for many years.

    In any case, we must end our dependence on fossil fuels as quickly as it is practical to do so both because the cost of petroleum is certain to rise and because of environmental considerations.
     
    #7 FRE, Jun 22, 2010
    Last edited: Jun 22, 2010
  8. FRE

    FRE
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    BIBLIOGRAPHY
    21jun2010

    Website: Energy from Thorium



    Terrestrial Energy by William Tucker

    Prescription for the Planet by Tom Blees

    The Nuclear Economy by Zachary Moitoza

    Nuclear Green by Ralph Andrews

    Whole Earth Discipline by Stewart Brand
     
  9. freyasworld

    freyasworld New Member

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    I am not an expert, engineer, power generation authority, but the way I see it there are 3 main areas to focus on to get away from our dependence on fossil fuels.

    Electricity Generation
    Peak energy generation
    and fuel for cars and vehicles.

    The last 2 there's absolutely nothing we can do about that, we can't have a PWR under the bonnet to take our kids to school! Electric cars need plugging in somewhere! So we are left with hybrids. Unless someone can make hydrogen on demand and push this through a fuel cell we are fcuked, or some brainbox becomes the richest man on the planet and invents a way of storing hydrogen gas safely and without it leaking! If my physics class is right (25+ years ago) hydrogen has the smallest atom and can pass through any material, oh and you need 4x as much hydrogen as petrol.

    Peak energy demand, again, nothing we can do about that, powerstations usually gas is used to meet peak demand.

    So that leave electricity generation, the normal oil/coal and nuclear plants that supply a constant amount of energy.I believe we can do something about that, micro-generation is I believe a way forward. solar cells on the roofs of buildings, homes offices, government buildings, schools etc, producing not only electricity but hot water. The governments can easily pass a law that states all new building must be fitted with solar panels, and PV solar panels, one sytem heats water, the other produces electricity, this can be put into the grid and sold to them, then when you use electricity buy it back.

    For company's tell them to generate 10% of their energy use and we'll give them a tax break for the investment of the equipment!

    Can you imagine that, when your out all day at work or next door, kids at school, you are generating electricity and forcing the electricity generating company's to buy this off you, now that got to be justice! Oh and the government is going to give you a grant to help pay you to do it. Get home jump in the shower, hot water, cost nothing!

    How smug can that make you feel!

    The spin off from that is job creation, new businesses setting up, service, maintenance etc etc. OK might run out of sand making the solar panels but I doubt it!

    Then retrofitting existing buildings, schools, colleges, hospitals etc. Obviously the governments will but tarrifs taxes on electricity, so it will cost more, the government gets more revenue, so some of that can be used for grants to reduce the usage of fossil fuels.
     
  10. FRE

    FRE
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    Freyasworld,

    You have obviously put considerable thought into your post. I shall comment on your points roughly in order.

    We can do something about peak energy generation. By billing according to the time of day when the power is used, the peak problem can be reduced to a LIMITED degree; that is already being done in some places. Where it is being done, some power users have air conditioning systems that produce ice during off-peak times to be used for cooling during peak times. Nuclear plants can be designed to deal with peaks although not without increasing costs. Also, the capability of power companies to shut down customers’ air conditioning compressors briefly could be expanded. Usually if a compressor is shut off for a few minutes no one would notice anyway.

    As you say, we cannot have nuclear reactors in cars and probably will never be able to do so. Hydrogen is not practical either, for the reasons you listed. However, ammonia and methyl ether are possibilities for fuel; they can be manufactured. It has been said that the carbon required for methyl ether can be obtained from the air, although I have doubts. There may also be other possibilities. Hybrids are a good transition technology, especially series hybrids where the engine-driven generator is used only as a range extender, like the Chevrolet Volt. Battery technology continues to improve. If an electric car could go 200 miles at highway speeds and the batteries quickly exchanged at service stations, electric cars would be more practical. Right now, the cost of that much battery capacity would be too high. Perhaps customers should be able to select the battery capacity they need depending on how they use the car.

    Solar hot water heaters are common in countries where there is plenty of sun and other sources of energy are expensive. It’s basically a matter of economics. However, they do not provide free hot water!! A solar water heater typically costs considerably more than an electric or gas water heater and the interest on the investment has to be included in the cost. Presumably if you did not spend the money on a solar water heater, you’d be able to invest the money in stocks, bonds, or in some interest-bearing account. When I lived in Fiji (1994 – 2004), I had a solar water heater and rarely had to use the electric back-up. A discounted cash flow or internal rate of return analysis is needed to determine whether a solar water heater can be justified.

    Unless forced to do so, power companies would not buy power from people who have PV panels. The presence of the PV panels does not reduce the capacity requirements of power companies and the cost of the coal they burn is only a small part of the cost of generating power. The required return on the investment, maintenance costs, depreciation, office expenses, etc. amount to from 5 to 10 times the cost of the fuel, so there is no incentive for them to buy power from owners of solar panels. The solar panels could, to a certain extent, REDUCE the amount of coal burned, but never totally replace it. I think we should aim to replace coal totally, not just reduce it. Also, the huge area PV panels require makes them impractical to generate a major portion of the power required by most countries. That’s especially true in countries with a high population density, such as China and India. Even so, there are places where they are practical.

    Solar panels have a useful life of from 20 to 30 years after which they need to be replaced. They contain toxic materials and I don’t know whether a workable recycling system for them has been developed yet.

    Micro generation using gas has its place for now, and is being used. It can be very efficient if the waste heat is used to provide air conditioning via the lithium bromide absorption cycle, and hot water. But, it still requires fuel and if our goal is to eliminate the use of fossil fuel, it is not a permanent solution although it probably has its place as a stop gap measure.

    France currently gets 80% of its electricity from nuclear power and it has been very safe. The cost of electricity is also very low there but, since the power system is government owned, that could possibly be misleading. However, the nuclear technologies they are using are not the best possible.

    As I see it, the most promising permanent solution for power generation is the lithium fluoride thorium reactor (LFTR). I am not a nuclear engineer and do not totally understand nuclear physics. However, the basic concept of the LFTR is simpler,
    more elegant, less expensive, and inherently safer than the pressurized water thermal reactors we are now using. LFTR generated power should be cheaper than coal generated power. I expect to see LFTR technology win.

    Again, I think that our long-term goal should be to ELIMINATE the use of coal for power generation, not simply reduce it. And, we should also aim to ELIMINATE the need for petroleum for transportation, but that may be more difficult.

    You seem to have a better understanding of physics than most people. If I had my way, physics would be a required subject at both the high school and college levels.
     
  11. dandelion

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    I have never heard this said before. Can you explain?

    Again this contradict my experience. Electricity prices in the UK have varied wildly with the market price of oil/gas/coal in recent years. If the fuel only constituted 20% of costs this would not happen.
     
  12. dandelion

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    I can see one from my house.

    It is possible to study wind if you have a mind to. I was listening to a program recently where they got in such an expert and discovered a turbine would have been pointless at the place in question, even though the general area was pretty windy.

    You dismissed the possibility of expanding existing hydroelectric schemes. It seems to me a logical place to put a pumped storage is scheme is right next to an existing hydro. The upper reservoir already exists, its just a question of pumping water back. I imagine the lower reservoir would be consdierably smaller than the upper.


    Only if your contention about the fuel being a small part of the cost is correct.

    If we become serious about alternative energy, then the supply model used by electricity companies will have to change. Experiments are currently underway with remotely controlled equipment, such as freezers, (or you said, air conditioning) so that companies can temporarily shed load, or defer it, to cover short term peaks. the principle of different tarrifs for electricity, eg cheap at 2am are long established at least in the uk although i dont think they have a significant effect. Consumers might have to learn they can only use the washing machine when the power company says so. No charging of electric cars without permission.


    In the Uk there are certainly issues about connecting wind farms eg in Scotland to the grid. Mostly these seem to revolve about persuading the companies to do the work in any timespan short of next century, not about the cost per se (though not cheap). It occurs that compared to the US, the UK is densely populated, small, and has a highly developed transmission grid already going all over most of it. Your arguments may be country dependant.

    Are you sure? Why do nuclear power stations use less steel? On the face of it, a nuclear steam generator is much more complex than a coal fired boiler. It has a vast containment building for starters. The actual generating plant is identical. Are you counting the expenditure on getting fuel to the plant (ie steel trucks and railways)? What has been factored in for fuel purification plant, development, mines, etc? Kentish flats offshore wind farm Kentish Flats offshore wind farm says 300 tonnes foundation plus 200 tonnes tower and turbine. Doesnt say how many megawatts capacity, but is that max or typical?

    As I said, you are presupposing that it is not acceptable to have energy only when the wind blows. If there was no alternative, we would adapt.
     
  13. dandelion

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    There is currently a tussle within the new UK coalition government over nuclear power. The conservatives are for, the libs against. The compromise reached is that the government will support and private company wanting to build a nuclear power station, provided it receives no subsidy whatsoever. The libs take the view that as no UK nuclear power station to date could have been built without massive subsidy, then none will be built. In short, alternative energy is not the only option requiring subsidy.

    You have already stated that your calculations are based on energy being only 20% of total costs. What happens when it reaches 95%? At present we make tiny amounts of PV cells. They will get a lot cheaper.


    an anachronism?

    As I just said. Even if this is now true, it will not be shortly.

    This is exactly the kind of compromise which will be required. Similar issues apply to wind turbines.

    I heard a discussion re installing vast areas of solar power in the north african deserts to power europe. One of the consequencs of all this generating would be to reduce the temperature in the aforesaid deserts,because basically we would be installing massive cooling plants. This might compromise the cloudless skies benefit of the (ex) desert, but the locals might quite like it if the land stopped turning into more and more desert as it now is.

    Apparently modern DC transmission techniques are significantly more efficient than the traditional Ac, so constructing a brand new supergrid might be cost effective.
     
  14. midlifebear

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    Fre:

    I like your run down on alternative power generation. I worked hard and against the local power company to get my Nevada ranch self-sufficient. We generate more electricity than we need with pole-mounted banks of solar cells and two wind generators. The only thing we are still a slave to is diesel and gas. However, as soon as a car manufacturer comes out with a 4x4 electric truck that can go at least 200 miles on a full charge, I'll be one of the first to buy one. Unfortunately, my ranch is a 170 mile round trip just to buy milk. So, we have an oil company come by and fill up two above-ground tanks for the same cost of my my undergraduate education (back in the 60s/70s). We have a couple of small electric vehicles for hauling hay, wire, and fencing. But they aren't as reliable as I wish they could be.
     
  15. dandelion

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    Consensus seems to be that it has never been cheaper than conventional alternatives in the UK. Final costs still remain unquantified, because no one has ever totally decomissioned a power station.

    Frankly, that is exactly why the UK built power stations, thought I think they started with MAGNOX, which used CO2 as the coolant rather than water. Its a long time ago, but I recall the fuel loading chamber as being much bigger than 15 feet across. (fuel is lowerd down into the reactor).

    No solution to the waste mountain has yet been devised. What we have is increasing amounts in temporary storage (rusty steel drums)

    As you know, the nuclear power program was halted because of the accidents. More will only be built if there is sufficient public (and industry) confidence in their safety.

    I recall a criticism of the UK nuclear program, that virtually every reactor was a new design.


    Given that they seem to be the best invention since sliced bread, and considering the emphasis on safety, why would anyone build any further PWRs?
     
  16. TurkeyWithaSunburn

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    One more problem with coal is there is less of it than what we thought.
    FuturePundit: American Coal Reserves Not So Big

    To get off fossil fuels for electricity is straight forward enough. Getting off fossil fuels for vehicle fuels will require some major engineering.
     
  17. dandelion

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    A recent discussion about some of the new battery cars which have just arrived noted that although the manufacturers claimed 150 miles per charge, the reviewers only managed 70-100. Although most daily journeys are less than this, most owners also occasionally drive much further. So keep a petrol car as well for the long trips?

    I think one of the company reps said that electric cars were now really possible because of the improvements in battery design ...since the last time they said electric cars were now possible due to improvements in battery design... The batteries are a big headache, very heavy which has obvious design issues for a vehicle operating at constantly changing speeds. petrol (or some similar hydrocarbon) is a very good fuel choice for this role.

    Yes, but there is a much better case for using petrol to run cars than for using oil/gas to heat houses.

    This is hard to quantify. The nuclear waste issue has not been solved. Plenty of theories, no action. The worst case disater scenario is very bad indeed.

    Perhaps more honest to say it makes PWR look an extremely bad idea.

    Unfortunately the timescale over which we must do this is longer than the period in office of any politician, so no one in power sees any urgency.
     
  18. dandelion

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    Research on hydrogen fuel cells is ongoing, though doing a quick search apparently obama just cancelled some. Didnt they get men to the moon using hydrogen fuel cells? Hydrogen is easy to synthesise if you have electricity and burns very clean.


    but it would be much cheaper if they were mass produces and installed on every house as a matter of course.

    As I said, Africa powering europe has been proposed. this is not an issue for countries to consider in isolation. Some have lots of desert. What would Australia do if it could generate vast amounts of energy cheaper than the US but had nothing to use it for?Use it produce hydrogen/hydrocarbon fuels for export?
     
  19. dandelion

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    ah yes, you missed that one Fre. Solar water heating is cost effective and efficient even in the UK.

    Also, in general, the best way to replace fossil electricity generation is to use less electricity and not generate it in the first place. This is simple, traditional technology in home insulation and efficient devices. Even works with motor cars to reduce fuel consumption. Cars need to be lighter.
     
  20. Drifterwood

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