Sunday, January 6, 2008

Alternative energy futures, an examination of costs

I think that the energy future belongs to Kirk Sorensen.

Here is my case. Almost all future energy schemes would require enormous amounts of energy, materials and time to implement. For example, advocates of wind power have argued, on the basis of a Stanford study, that they have located 19 places in the United States where the wind is sufficiently reliable to provide base power, provided those localities are linked. Indeed if only 10 of the 19 localities are linked, the researcher argue that conditions required to be regarded as a base power resource will be meet.

Here is the problem I see. First, wind generators, very seldom produce electricity at even 50% of rated capacity. A wind generator is considered doing well if it produces power at one third of rated capacity. No the Stanford researchers calculated that if you link power generation from 10% very good wind generating localities, that between 33% to 47% of the generated electricity can be considered base power. Prudence would require that we consider the lower figure, for this is a don't count your chickens until the eggs are hatched situation. So assuming an output of 33% of rated capacity from the operating wind generators, and that a 33% of the generated electricity can be counted as base power, then base power = .33 X .33 of the rated capacity of operating wind towers. That is about 11% of rated capacity. If, for the sake of argument, we assume the 47% base load figure, we get a little over 15% of rated capacity as reliable base load power. It gets worse. The Stanford calculations found that base load power might be flowing from as few as 3 out of 10 wind farms at any one time. This means that 11% to 15% or the rated power resources of any given wind farm, must be able to supply the targeted base load electricity.

How many wind towers are we talking about then? One guess I have encountered is one million. We are talking then about lots of concrete and steel going into upwards of a million 200 foot tall towers, with 10 to 20 ton wind generators on top. We are talking about a lot of man power. We are talking about an enormous collection system. We are talking about a hell of a lot of resources.

A utopian Scientific American article titled "A Solar Grand Plan," proposed a scheme to provide 69% of American electricity from solar sources by 2050. The proposal suggests that as much as 35% of American energy needs can be supplied from solar sources located in the desert Southwest. Global warming researchers suggest that by 2050, we should cut our fossil fuel use by 80% as part of a plan to bring anthropogenic global warming under control. Thus the "Grand Plan" offers well under have of the energy needed from non-carbon sources. In addition, plan writers failed to consider that the most likely substitute for fossil fuels in surface transportation is electricity stored in batteries or capacitors. Thus the electrical system may be expected to provide somewhere between 60% and 80% of the national energy demand.

The "Grand Plan" suggests that 35% of American energy needs can be produced from "solar farms, that cover 8500 square miles of desert real estate. Consider 85oo Square miles of desert covered with row after row of solar panels, or mirrors and towers. Think of it in terms of materials that have to be fabricated. Think of the refined silicon, the glass and steel, think of the wiring in the collection system. Now think what you need to store electrical energy over night. I recently attempted to price battery backup for renewable energy, and found to my astonishment that 16 GWh's of sodium sulfer (NAS) battery backup might run as much as nine billion dollars. A nuclear power plant which would cost far less, would provide more power for 24 hours a day. It gets worse. The batteries have a project life span of 15 years. Nuclear plants have been shown to last for at least 60 years.

The "Grand Plan" suggested storing energy in the form of compressed air in caves, and then generate electricity on demand by releasing the air through turbines, and perhaps burning some natural gas in the air stream. There is no indication in the Scientific American story that anyone has actually tried to seal air at high pressure in a cave. Nor have such caves been identified, as far as I can tell. Given the lack of experience with this technology, it is impossible to say how much it would cost, provided it can be made to work at all.

A third scheme for Sandia Laboratory involves the heating of molten salt in a Solar thermal aray. Sandea is quite excited about this, and they are quoting prices as low as $0.08 per KWh for base power using this system. This would be quite impressive if we actually saw a commercial ST system using molten salt technology built and texted. But Solar Thermal manufactures have not done that yet, and they quote prices of from $0.17 to $0.31 per KWh. b Indeed ST manufacturers quote prices of as much as $7.00 Per KW, for installed systems. Since the most pessimistic estimate of the price of new nuclear plants is $3.50 per KW, it is clear that solar power is at present no bargain.

The reason for high solar cost is simple. High material demand, high manufacturing costs, and high installation cost all are part of the cost picture. Add to that the cost of construction in remote locations, and the cost of electrical connections and connections to the grid. Figure that energy storage is also going to cost. As with wind we are clearly talking about an enormous amount of materials required to build some variant of the Scientific American Grand Plan. It is not clear if enough material resources will be on hand to tackle the Scientific American "Grand Plan." The Scientific American Grand plan called for a public subsidy of $420 billion. We need a basis for guesstimating what a per square mile for solar electrical instalation would cost. One billion dollars a square mile is not beyond the realm of possibility. Such a figure will, however, drive the solar fanatics crazy, so assume for the moment a cost of $500 million per square mile. This would give us a price of $4.25 trillion for our 85oo sq mi solar field. Add the $420 billion public investment, gives us $4.67 trillion cost to generate 35 percent of American energy requirements via a solar system. This is without the anticipated resource inflation.

Let us now turn to another option for solving our energy crisis, that would be a plan to draw our energy of Light Water Reactors. Let us assume that the 100+ civilian power reactors currently being operated in the United States will have to be replaced by 2050 as well. We would need about 1000 reactors to supply the required 80% of US energy by 2050. Westinghouse is able to deliver an unassembled reactor for a little more than one billion dollars per GW. Construction of the reactor containment facility and generator room, spent fuel holding facilities, and electrical switching facility, plus assembly of the reactor will cost from $1.5 to $2.5 billion. Westinghouse and GE have made significant progress in lowering material and labor costs, but we are still talking about a lot a material that goes into the construction of AP-1000 light water reactors. Thus the total cost of replacing 80% of American energy output with LWRs would be somewhere between 2.5 and 3.5 trillion. Inflation in the cost of resources could well raise the price.

What ever energy plan the United States adopts for replacing fossil fuel generated electricity, we are going to be competing with the rest of the world for resources to implement our plan. That means that the price of raw materials and manufactured parts most likely will rise rather than fall as we near 2050. A very good plan to meet the 2050 target would make modest resource demands. Light Water Reactors might well require fewer resources than wind or solar schemes but they are still resource hogs, and they have significant bottlenecks. Light Water Reactors require enormous forged steel pressure vessels. The world manufacturing capacity for such vessels is no where near the expected demand, and such forging facilities can neither be built quickly or cheaply. We should not forget that 7 years of the Bush administration has left the United States with an enormous trade deficit and a dollar that is falling in value. These problems suggest that resources obtained from abroad may be far more expensive in the future than in the past. We thus need a plan which will use local resources, as much as possible.

We have now here is where Kirk Sorensen comes in. The Molten Salt Reactor makes truly modest resource demands. It requires less steel. Because the reactor coolant is not under pressure, it does not need a pressure vessel. Because the core is already molten you don't need an emergency cooling system to prevent core melt down. The emergence system for core overheating, is simple, passive and very effective. There is no problem with hydrogen buildup inside the reactor, and no high pressure steam to explode. The escape of reactor produced radioisotopes is far less of a problem, thus containment requirements are also modest.

Finally small molten salt reactor units, with attached power output generators pre-attached, can be produced on assembly lines and shipped via rail or water born transportation to their final destination. They can either be set up in low price containment buildings, or situated in underground chambers. An inner radiation protection structure would also serve for extra containment protection.

Such structures can be situated close to existing power transmission lines, thus expensive additions to the grid will not be required. Small Molten Salt reactors can be air cooled. In addition their wast heat can be used in cogeneration, or for the distillation of sea water.

How much would installing molten salt reactors cost per KWh? If we consider that Westinghouse has recenly sold light water reactors to China, for about $1.2o per K, it would seem likely that molten salt reactors can be delivered as completed unites for from somewhere between $1.00 and $2.00 per KW. This would bring us to a price of between one and two trillion dollars for supplying 80% of the national energy requirements.

Although the Molten Salt Reactor does require new few from time to time its new fuel requirements are limited because it burns almost all the potential energy in natural uranium or thorium. The worst possible case for capitol costs for 1ooo GW of Molten Salt reactor power generating capacity, will be far less than the capitol cost for far less generating capacity from solar power. In addition the material inputs costs for molten salt reactors will be far less subject to inflation, because fewer scarce minerals are involved in molten salt reactor construction.

For our modest investment in Molten Salt Reactors we will get the capacity to dispose of nuclear waste. A solution to world wide energy problems that will last for thousands of years. We get the energy independence which has eluded the United States for the last 40 years. We get great flexability in reactor location. We get the capacity to use waste heat, for industrial purposes, for space heating or cooling, or for for sea water desalinization.

1 comment:

DV8 2XL said...

Of course everything you say is true. The problem has never been a lack of technology, but rather a warped political agenda.

Until the influence of the carbon energy sector is broken the only 'solutions' that will get any support are those that are guaranteed to fail.

Solar, wind, and wave power, pose no threat to the traditional carbon-based suppliers, as renewables can never reasonably be able to deliver more than 20% of base load under the best of conditions.

Only by pressing for laws that will make the rest of the energy supply sector assume the same level of responsibility for their wastes as nuclear must will it be possible to move forward.

Renewables are a red herring that nuclear energy supporters should ignore, they are not a threat to our agenda. We should spend our efforts fighting coal.


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