Showing posts with label transmission costs. Show all posts
Showing posts with label transmission costs. Show all posts

Friday, January 22, 2010

Robert Zavadil on "The Eastern Wind Integration and Transmission Study"

How much will increasing wind penetration in the United States grid cost? Is increasing wind penetration really the low cost route to post-carbon electricity? Yesterday, I read with interest, Joe Romm's post titled, NREL study shows 20 percent wind possible by 2024 - Half a million jobs, 25% drop in utility carbon pollution for just 2 cents a day per household. The post was ostensibly a review of a DoE study, Eastern Wind Integration and Transmission Study(EWITS). Joe began his post with an account of a previous DoE report on the cost and consequences of a large scale wind buildup. 20% Wind Energy by 2030: Increasing Wind Energy’s Contribution to U.S. Electricity Supply.” Joe had uncritically accepted the conclusions of the earlier study, but I had some some questions about that earlier study, because it had not focused enough attention on the future inflation of wind construction costs. Plans to dramatically increase energy related construction should assume that their implementation can and probably would exert inflationary pressures on construction costs.

There is a policy issue here. Wind electrical generation receives significant subsidies from the tax payers, and these subsidies are justified by the claim that wind is an economically desirable post carbon electrical source. Wind supporters refer to the high capital costs of of nuclear power, but are the capital costs of wind really lower? The EWITS report did not really address that issue, but I noticed that the report had actually been prepared by EnerNex Corporation of Knoxville, Tennessee, which meant that I could speak to one of the reports authors with a local phone call, so i put on my intrepid reporter cap, and called Robert Zavadil of EnerNex, and asked him about comparisons of wind and nuclear costs. Robert dodged my question by answering that future nuclear costs are something of a mystery, but this is equally the case with the future cost of wind generation.

Thus we are not going to reach anything like a firm conclusion about he relative costs of wind and nuclear, but the EWITS report does contain a lot of hints. For example, the EWITS states,
The EWITS LOLE studies show that when the geographic diversity of the Eastern Interconnection is considered, the capacity credit could increase to 25%.
The lowest cost of the 4 wind scenarios which the EWITS considers envisions the construction of 225 billion watts of wind generation capacity for the Eastern Interconnect. This means that 225 billion watts of wind generation capacity can be expected to typically produce about 56 GWs of electrical output during periods of peak energy demand. About 61 GWs of nuclear capacity would produce the equivalent capacity credit. Thus to start to understand the relative costs of wind an nuclear we could begin by comparing the costs of 225 GWs of wind with the costs of 61 GWs of nuclear generation capacity.

Robert Zavadil acknowledged that the EWITS estimates of nuclear, on shore wind and offshore wind and offshore wind were all to low, although the nuclear estimate was probably about 70% lower than was actually the case, while the wind estimates were off by a far smaller margin. Even given this disparity, the cost of the equivalent wind capacity credit would still be 50% higher than the cost of that of nuclear. And in addition a stable wind entails an enlarged transmission system and
With approximately 22,697 miles of new EHV transmission lines, the transmission overlay for Scenario 1 has the highest estimated total cost at $93 billion (US$2009).
You can buy quite a few reactors for $93 billion, but of course you might also want to spend some of that on transmission system upgrades. Thus while we cannot get exact estimates of the relative costs of large scale future wind and nuclear grid penetration, the analysis presented by the EWITS is consistent with an additional 20% nuclear Eastern Interconnect penetration, rather than the equivalent wind penetration, having a lower costs.

Saturday, November 21, 2009

My Energy Collective debate is finally winding down

My debate with Stephen Gloor, an Australian pro-renewables engineer, seems finally to be winding down. I have been very ably assisted by Bill Hannahan, Rod Adams, and Nathan Wilson. This morning I wrote the following comment:
Stephen, you have in our discussion nicely illustrated the case against renewables, while offering your defense of renewable power systems. When confronted with the limitations of wind, you offered redundant dispersed wind installations as a solution. When it was pointed out that wind dispersion still left gaps in wind electrical generation, you offered solar-wind redundancy as a solution. Against the case that solar and wind both fail over wide areas, you offered another redundancy, the CO2 emitting use of natural gas as a backup to the not always reliable renewables system you call for.. Your solution also requires an enormous and expensive expansion of the electrical transmission system. I have called attention to a statement by a electrical transmission systems expert that an all renewables generation system would require 75 thousand miles of new transmission lines for California alone, in order to make the system reliable. Your solution to almost any renewable reliability problem is to build further, redundant renewable facilities, and connect them up with hundreds of thousands of miles of transmission lines.

You claim that nuclear construction it too slow, but nuclear power with its superior reliability, and its potential to be located near consumers, is far far more easily scaled to meet carbon free energy requirements, and to fulfill consumer demands than renewables are.

You never once stop to count the cost of the multiple redundancies and grid expansion you advocate. When confronted with the fact that even with the huge investments in wind, solar and natural gas facilities, there still would be uncovered problems like summer peak demand, in areas like Texas. Your response was to call for even more huge investments in energy efficiency. Thus you like other renewables advocates never stop to count the cost of your solutions, you simply recite the claim that nuclear is too expensive, while ignoring the fact that the renewables system you advocate would be far more expensive. You argue that reactors cannot perform load following, despite the fact that nuclear load following is performed as a matter of course in the French electrical system. You reject the possibility that nuclear research and a new generation of nuclear technology might lower nuclear costs.

Conclusions from our debate:
1. Renewable advocates have failed to make a convincing case that wind plus natural gas "backups" actually saves significantly more CO2, than wind alone. Money spent on wind generators is not justified unless a strong case exists that they actually save CO2.
2. Wind generators seldom operate at full capacity. Redundant wind generators are required to equal the capacity factor of reactors.
3. Even with multiple generators, natural factors such as day and night influence wind output. To achieve high renewable penetration, wind generators require daytime solar back up. The solar backup is a second form of renewables redundancy. In order to insure the availability of solar generated electricity during all daylight hours, heat storage is required, Heat storage requires redundant gathering fields, in order to insure that enough heat is collected during limited daylight hours.
3. All forms of energy storage, if used with renewables, require redundant generating capacity to service them. In addition the storage-generator unit is a further redundant electrical generator.
4. Even with significant redundancies, a high renewables penetrated grid requires significant natural gas backup. Natural gas backups thus form a further redundancy.
5. Renewables seldom can be located close to energy customers. Transmitting electricity from renewables generating facilities to customers usually requires new and expensive transmission lines. The cost of those transmission lines are a hidden cost of a renewable generation system, Using renewables output from other regions as a backup to local renewables requires still more new transmission lines. These interregional transmission lines that would not be required by an all nuclear grid, are transmission redundancies required to support a renewable power system.
6. Construction of nuclear power plants use significantly fewer materials than the construction the construction of solar and wind facilities require. The United States must compete with growing Asian economies for construction materials, and the current trade balance places the United States at a significant and growing disadvantage in this competition. Hence the cost of power generation facilities construction can be expected to rise during the next 15 years, with the cost of renewables rising more than the cost of nuclear power. The rise in materials cost, will also effect the cost of transmission lines, and this will effect the cost of an all renewables system far more than the cost of an all nuclear system.
7. Renewables advocates when confronted by the limitations of renewable energy and its high cost, fall back on a further redundancy, and that is efficiency. Efficiency advocates point to potential energy efficiencies, but seldom attempt to understand why these efficiencies are not already being adopted. Efficiency advocates often believe that naming an efficiency and describing it as a low hanging fruit is the same thing as demonstrating that it is a low cost alternative to building generation facilities. This is not in fact the case.
8. Renewables critics of nuclear power never reference renewables cost and compare the total cost of an all renewables electrical system, with the cost of an all nuclear electrical system. But judging from the current cost of renewables generation facilities, their capacity factors, and the added cost of new transmission lines needed to bring renewable generated electricity to distant customers, and the likely inflation of the cost of materials, the total cost of an all renewables system is likely to be several times higher the cos of an all nuclear system.

Friday, November 20, 2009

2025 Economic Developments in China and India, and the Future of American Solar and Wind

Brian Wang has a very interesting post based on economic projections by Rio Tinto, the international mining outfit. Rio Tinto clearly wants to know about future metal demands in the global economy. Of course this is important for Rio Tinto to know since it takes both time and a lot of capital to develop a new mine, and an accurate future projections is a way to control investment risks. Rio Tinto's projections are most interesting because they foresee the most significant driving force in the world economy as the development of China. The development of India will be a second major world economic driver. The Rio Tinto projection focuses on the next 15 years, and foresees rapid advances for both Chinese and Indian economies, with dramatic increases in personal income and standards of living. From Rio Tinto's perspective, the most important aspect of this picture is the demand for metals, and Rio Tinto for sees dramatic increases in Chinese and Indian demand for copper, and by implication for iron (steel) and aluminum.

While it would be fascinating to speculate on the consequences of these developments on the peoples of China and the United States who will by 2025 find themselves in the middle of an energy crisis, brought on by a decline in the world supply of petroleum, and the certainty of Anthropogenic Global Warming. I am assuming that by 2025 reality will have caught up with the most confirmed AGW skeptic. What I am interested in is how the economic development of China and India will impact the American efforts to deal with this dual energy crisis.

The Rio Tinto model suggests that Asian demand for the raw materials for developed societies, such as copper, steel, aluminum and cement would increase, and by implication there will be a steady increase in the price of these commodities. It will be plausible then the price in American dollars for copper, steel, aluminum and cement will be much higher than it is now, and that the ability of the United States to compete for these commodities on the international market will be seriously compromised by the large American international debt, especially the debt to China.

The competitive disadvantage of the United States will adversely effect many of its options in dealing with the dual energy crisis, because the raw materials for building new energy producing resources will be subject to increasingly onerous dollar inflation of materials costs. These developments will preclude energy approaches that will require high levels materials inputs, and will favor energy sources that will use lower cost materials, or smaller material inputs. These factors would tend to favor nuclear energy over renewables for both obvious and hidden reasons. The obvious reason is that nuclear requires far less copper, steel, aluminum and cement by the kW of generating capacity than Wind and Solar generating facilities do. We can infer from Barry Brook's discussion in the previous link, that the material requirements for a large renewables development in the United States would make such a development unsustainable.

Renewable advocates seldom talk about costs, that is advocates with the exception of Ed Ring. Prior to the 2008 vote on California Proposition 7, which mandated that by 2025 50% of California power be produced by renewables. Ring observed:
There is nothing wrong with encouraging clean, renewable, domestically produced energy. But California’s proposition 7 “would, if approved, require California utilities to procure half of their power from renewable resources by 2025" . . .

since Californians by 2025 are going to be consuming about 1,000 gigawatt-hours per day, if proposition 7 is enacted, 500 gWh per day will have to come from wind and solar power.
Solar power, installed – not including transmission or storage infrastructure – costs about $7.0 million per megawatt of output; this equates to $7.0 billion per gigawatt. If this sounds expensive, it is, but to get a truly accurate price you have to also take into account yield. Even in sunny California, solar energy (in terms of full-sun-equivalent hours), can only be harvested on average for 4.5 hours per day, which means to get 500 gWh of solar generated electricity each day in California, you would need to install 111 gigawatts of solar arrays (500/4.5), which would cost $777 billion dollars.
Wind power, installed – is a better deal currently than solar – insofar as you can probably get costs down to around $2.5 million per megawatt of output, or $2.5 billion per gigawatt. But the yield figures are also not promising. In California there is widespread disagreement on the yield for wind power – credible estimates range from 10% (2.4 hours per day) to 25% (6.0 hours per day). Given the magnitude of what is being proposed, it would be prudent to project wind yields in California somewhere in the middle of this range, say 17.5%, or 4.2 hours per day. This means to get 500 gWh of wind generated electricity in California you would need to install 119 gigawatts of solar arrays (55/4.2), which would cost $297 billion dollars.
Ring added,
It is tempting, and not entirely implausible, to expect prices for solar power to drop significantly over the next several years. But given the cost of balance of plant and installation labor, it is unlikely solar electricity is going to get measurably cheaper than wind power no matter how inexpensive the actual collector materials become. Moreover, the costs for new transmission lines and grid upgrades, the costs for massive energy storage units (since the sun and wind are only producing power during small portions of the day), and the costs for land aquisition, permitting and fighting environmentalist lawsuits will be substantial. For these reasons, estimating the total cost for California to deliver 50% renewable electricity at $300 billion is probably the very best case, if not fantastically optimistic. This is $20 billion per year for the next 15 years. Readers are encouraged to critique these projections.

Ring, did not include the costr of materials inflations in his estimate of costs.

A second serious materials problem for the development of renewables is materials requirements for electrical transmissions systems necessitated by the remote locations and the necessity of generation backup associated with a renewable dominated grid. Electrical Engineer E.G. Preston, who "by profession" does
transmission studies for wind and solar clients.
Preston, who has a PhD in Electrical Engineering, has an very impressive resume, clearly qualifies as an expert on renewables transmission, that is someone who would be accepted as an expert witness in court cases involving renewable related electrical transmission. In addition Preston does not have an ax to grind. Thus what he has to say about renewables transmission systems deserves serious attention. commenting on the recent Jacobson-Delucchi Scientific American article, A path to sustainable energy by 2030", Preston states:
Because the wind and solar and water and geothermal projects are not in the locations of the existing power plants, new lines will be needed. Looking at the graph on page 63, and carefully measuring scales on the graph, I estimate that there is 40,000 MW of wind and 40,000 MW of centralized solar on that graph. . . That leaves us needing 80,000 MW of new wind solar and geothermal generation just to serve California. I think an estimate of 500 miles from wind and solar resources to major load centers is reasonable. A 500 kV transmission line is rated at about 2000 MW max power. But you don't want to operate it at that power level because the losses are too high and there is no reserve capacity in the line to handle the first contingency problem. Therefore I will estimate we will load the new 500 kV lines to about 1500 MW on average. So we have 80,000 MW of renewable sources widely scattered around the Western System (WECC) with each carrying 1500 MW so that we need roughly 50 new 500 kV lines of 500 miles each, for a total length of 25,000 miles.
Preston adds
The article assumes there is little solar power energy storage and it also assumes the wind be blowing at night. We know for sure that the solar power is not available at night so we are nearly totally dependent on wind for night time energy. You are going to ask about the geothermal energy. One geothermal project I recently worked on for determining the transmission access for looked like a good project until the geothermal energy extraction failed to work. Recently other geothermal projects have created human induced earthquakes. Geothermal energy seem less likely today than just a few years ago. So we are nearly totally dependent on wind energy for the nighttime CA energy as envisioned in the 100% renewables by 2030. If we plan for those few occurrences when there is no wind in the WECC system, we must interconnect WECC with the rest of the US so CA can draw power from other wind generators that do have wind (hopefully) outside the WECC area, such as the Texas coast and east of the rocky mountains where massive wind farms can be constructed. However we will need at least 40,000 MW of lines that I estimate will average 2000 miles in length. If we used 500 kV lines, we would need about 25 of these lines bridging from WECC to the US eastern grid and ERCOT and the total length would be about 50,000 miles.
Of course, the increased cost of materials will effect the cost of transmission lines as well.

Prestons estimate is far more parsimonious in its guess about the number of solar and wind installations require to meet California's electrical need, and given a system of the magnitude Ring foresaw to meet California's 2025 electrical needs, a far larger local transmission system would have been required. Given the nuclear power cost advantage of both China and India over the next 20 years, the energy future of the United States and indeed the economic future looks quite dismal without a major technological breakthrough.

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