Wind Redundancy I: Archer-Jacobson

The Wikipedia explains engineering redundancy with the following formula:

Each duplicate component added to the system decreases the probability of system failure according to the formula:

P =

where:

• n - number of components
• c p_i - probability of component i failing
• P - the probability of all components failing (system failure)

The failure in this case would be the failure of wind components of the grid. For wind temporary component failure would be the rule rather than the exception, and the high likelihood of failure means that redundancy is necessary for any wind penetrated grid system, almost to the extent the system relies on wind generated electricity.

Here is an example of a suggested use for redundancy to increase the reliability of a wind system:

the power guaranteed by 7 and 19 interconnected farms was 60 and 171 kW, giving firm capacities of 0.04 and 0.11, respectively. Furthermore, 19 interconnected wind farms guaranteed 222 kW of power (firm capacity of 0.15) for 87.5% of the year, the same percent of the year that an average coal plant in the United States guarantees power. Last, 19 farms guaranteed 312 kW of power for 79% of the year, 4 times the guaranteed power generated by one farm for 79% of the year.

Thus by lining up an array of 19 geographically dispersed wind generators, the authors. Cristina L. Archer AND Mark Z. Jacobson propose to increase the reliability of wind generating systems. The one question which Archer and Jacobson did not answer is how much would it cost. If we assume that system operators will want the 87.5% reliability, that means, the authors tell us a firm capacity of .15, then we will be able to count part of the capital cost of the generators in the system. The most recent Wind Generators for the most recent West Texas wind project, are priced at $2.5 million per MW installed. At .15 capacity the cost of one MW of 87.5% reliable wind generating capacity would be $2.5 million divided by .15 or a $16.75 in wind investments per every kW of reliable wind generating capacity. But that would not be the end of the investment, because the Archer-Jacobson system would require a large number of high voltage electrical lines to gather the electricity produced at 19 separate locations in 4 different states. More high voltage lines would be required to carry electricity from the central location or locations to Texas or California cities where electricity would be consumed.

Drew Thornley offers a discussion of ERCOT wind transmission cost studies. Thornley reports:

According to ERCOT, 138-kV lines cost $1 million per mile, while 345-kV lines cost $1.5 million per mile. See Competitive Renewable Energy Zones (CREZ) Transmission Optimization Study, ERCOT System Planning (2 Apr. 2008).

That is overnight costs. According to Thornley, 500-kV or 765-kV lines are even more expensive. Thus

Energy consultant Jeffry C. Pollock quantified the rate impact of future transmission investment on various customers.† Taking into account rising material and la- bor costs, interest/financing costs, and routing issues, the installed cost for CREZ Scenario 2 is estimated to be $7.8 billion ($3,282,828.28 per mile).

In the case of the Archer-Jacobson plan, the gathering and transmission system would be far more ambitious and expensive than ERCOT's CRUZ plans which only transmit electricity from wind farms in West Texas.

A further and until now unnoticed consequence of the Archer-Jacobson plan is what I call its carbon penalties. Carbon penalties are the added and usually hidden CO2 costs of attempts to make renewable schemes work. Professor Manfred Lenzen from the University of Sydney estimates that CO2 costs related to wind generator construction amount to from 30 and 60 grams of C02 per kilowatt hour. But redundancies inherent in the Archer-Jacobson plan would multiply the CO2 penalty for wind by from 6.67 times. The carbon penalties for Archer-Jacobson reliable wind will run from 200 to 400 grams per kW hour, but in addition there would be further carbon penalties for the electrical gathering and transmission systems necessitated by the Archer-Jacobson plan. I am unaware of studies that address the carbon costs of transmission systems, but surely there must be some. Thus not only would reliable power under the Archer-Jacobson plan cost far more than than equally reliable power from conventional nuclear generators, but carbon emissions from the construction of large numbers of redundant wind generators, necessitated by the Archer-Jacobson plan, would lead to far higher carbon penalties for reliable wind, than for reliable nuclear electricity.

Future power costs

It is impossible to determine the cost of commercial LFTRs with a high degree of certainty, although it is reasonable to assume that LFTR costs would be lower than LWR costs. LFTR costs are impossible to determine for a variety of reasons. First there are numerous design options, and each design has its own rationale and cost considerations. In addition to design options there are material options. Transportability would be an important consideration, but there may be important transportability options. For example, suppose that the largest truck transportable LFTR would produce 100 MWe, but for an added 25% of the cost of the smaller reactor, it would be possible to build a 400 MWe reactor. Further more the larger reactor although not transportable by truck is transportable by train and barge, and can be transported to 95% of the proposed sites. Most of the customers would prefer the larger reactor if it were available. The decision between the two options is clear and easy to make. Other choices might prove more difficult. Size might effect transportability, but that problem could still be solved. Function might point to design decisions. For example a reactor intended to provide summer peak power, might be built of less radiation resistant materials on the grounds that it will be used only 25% of the time, and thus parts would have a much smaller radiation exposure.

It is clear then that decisions about reactor function, materials, and design are made, no realistic assessment of cost would be possible. What can be asserted is that there is a considerable potential for producing lower cost nuclear power with multiple areas in which cost lowering is possible. These potential areas of cost savings would include lower manufacturing labor input per KW of power capacity, relatively simplicity of design, fewer parts, simplified assembly, shorter manufacturing time, simpler and lower cost housing, The potential to recycle old power plant facilities and grid hookups, faster building time, smaller capital risk, and lower financing cost. It would be impossible to quantify these savings, in any meaningful way, but the potential exists for the production of LFTRs at a cost that is significantly less than the cost of LWRs.

One further area of cost ought to be mentioned, and that is the cost of compliance with NRC regulations. The NRC or a successor agency would license LFTRs for construction.

We would have to know a great deal more about costs, before we can begin to pin down the costs of the LFTR. It should be noted however that it is not possible yet to estimate the cost of new conventional nuclear plants with any precision. At presence estimated cost ranges for plants to be completed in the middle of the next decade run from $4 to $8 billion per GW. It should be expected that cost estimates for a new technology would be far more inaccurate than cost estimates for a mature technology.

Nor is easier to project the price of renewables into the future. Indeed the current price of renewables power generating projects is not easy to find. One wind industry source suggested:

The costs for a commercial scale wind turbine in 2007 ranged from $1.2 million to $2.6 million, per MW of nameplate capacity installed.

This estimate should be considered outdated because the cost of many 2008 wind projects exceed this range. No industry source has estimated the 2008 cost range for wind turbines. I noted a range of reported costs for eight North American onshore wind projects of between $2200 and $3400 per KW of name plate capacity. Because these cannot be considered more than random cost estimates, and the sample was to small and arbitrary to be considered draw any conclusions from about 2008 prices, it is consistent with there having been a considerable cost increase for wing projects in 2008. The price of construction materials dropped dramatically during the second half of 2008. Whether this would have any impact on the cost of wind projects is still unknown. Thus it is impossible to determine current price for wind projects in the United States from sources available on the Internet. How much more then is the cost of future wind projects uncertain. It should be noted that we are here discussing the cost of wind projects without energy storage. Adding the price of energy storage undoubtedly will increase wind costs, but if anything adds a considerably greater measure of uncertainty to future costs.

If the future cost of wind projects is uncertain at best, it would be at least as difficult to project the cost of solar generation projects into the future. Although solar advocates repeatedly suggest that dramatically lower prices for new solar generation capacity is in the offing, this has yet to be observed in reported prices of actual solar generation projects. Still less has it been offered in projects with the energy storage required to make solar generated electricity reliable.

I have elsewhere in Nuclear Green offered prices estimates based on current wind costs with storage in order to suggests that the future cost of nuclear power most likely would be lower rather than higher than the cost of reliable renewable generated electricity.

My conclusion then is hat it is probable but not certain that the capital costs of conventional nuclear generation capacity will be lower than the capital cost of reliable renewable generation facilities. Further I have argued that the capital costs of LFTR based generation facilities will probably be lower than the cost of conventional nuclear generation capacity. I realize that these conclusions will be controversial, and I invite further research on the question.