Energy from Wind: A Discussion of the EROI Research
Posted by Nate Hagens on October 19, 2006 - 1:55pm
Topic: Alternative energy
Tags: eroei, eroi, lifecycle analysis, net energy, renewable energy, wind [list all tags]
This is a guest post by Cutler Cleveland. Dr. Cleveland is a Professor at Boston University and has been researching and writing on energy issues for over 20 years. He is Editor-in-Chief of the Encyclopedia of Earth, Editor-in-Chief of the Encyclopedia of Energy, the Dictionary of Energy and the Journal of Ecological Economics. He has particular interest and expertise in the field of net energy analysis.
As the world transitions from fossil based energy systems to a larger portfolio of renewables, the tradeoffs between energy quantity, energy quality and environmental impacts will increasingly need to be compared using meaningful metrics. Wind energy seemingly provides high returns, high quality energy (electricity) with minimal large scale environmental impacts.
The post below the fold is Dr. Cleveland's and Ida Kubiszewski's 2006 meta-analysis on wind, "Energy Return on Investment (EROI) for Wind Energy".**
ENERGY RETURN ON INVESTMENT (EROI) FOR WIND ENERGY
Wind energy is one of the fastest growing energy systems in the world. In Europe and the United States, wind-powered generating capacity increased by 18 percent and 27 percent, respectively, in 2005 alone. While the rate of increase is impressive, wind still accounts for less than one percent of the world's electricity generation.
The surge in wind energy is due to a combination of factors, including reduction in the cost of wind turbines, volatile prices for conventional forms of energy, the demand for non-carbon forms of energy to mitigate the effects of climate change, and generous government subsidies such as feed-in tariffs in Europe and the production tax credit in the United States.
One technique for evaluating energy systems is net energy analysis, which seeks to compare the amount of energy delivered to society by a technology to the total energy required to find, extract, process, deliver, and otherwise upgrade that energy to a socially useful form. Energy return on investment (EROI) is the ratio of energy delivered to energy costs. In the case of electricity generation, the EROI entails the comparison of the electricity generated to the amount of primary energy used in the manufacture, transport, construction, operation, decommissioning, and other stages of the facility's life cycle (Figure 1).
Figure 1
Comparing cumulative energy requirements with the amount of electricity the technology produces over its lifetime yields a simple ratio for energy return on investment (EROI):
EROI = (cumulative electricity generated) / (cumulative primary energy required)
This article reviews 112 wind turbines from 41 different analyses, ranging in publication date from 1977 to 2006. This survey shows average EROI for all studies (operational and conceptual) of 24.6 (n=109; std. dev=22.3). The average EROI for just the operational studies is 18.1 (n=158; std. dev=13.7). This places wind energy in a favorable position relative to conventional power generation technologies in terms of EROI.
Methodological Issues
System Boundary
The choice about system boundaries is perhaps the most important decision made in most net energy analyses. One of the most critical differences among the diverse studies is the number of stages in the life cycle of an energy system that are assessed and compared against the cumulative lifetime energy output of the system. These stages include the manufacture of components, transportation of components to the construction site, the construction of the facility itself, operation and maintenance over the lifetime of the facility, overhead, possible grid connection costs, and decommissioning. Energy systems have external costs as well, most notably environmental and human health costs, although these are difficult to assess in monetary and energy terms. No study as yet attempted to assess the environmental costs of wind energy in energy terms.
Methodology
Three types of net energy analysis techniques are used to calculate the net energy derived from wind power: process analysis, input-output analysis, and a hybrid analysis. The assumptions, strengths, and weaknesses of these approaches are discussed here.
Operating Characteristics
Many analyses must make important assumptions regarding the operating characteristics of wind turbines. These include power rating, assumed lifetime, and capacity factors. Changes in the assumptions made about these factors, or deviations in actual operating conditions from assumed conditions can have a significant impact on results.
Conceptual versus Empirical Studies
Some studies use the theoretical or ideal operating characteristics of a wind turbine that are derived from simulated or assumed costs and operating conditions, e.g., a wind turbine of a given power rating, costing a certain dollar amount, in a location with an assumed wind power density, with an assumed capacity factor, and so on. Of course, actual operating conditions always deviate from assumed conditions. Empirical analyses rely on actual costs, operating conditions, and energy outputs, and thus provide a better metric of an energy system's contribution to a nation's energy supply. This article focuses primarily on empirical studies based on actual operational data.
Results
The above table provides the detailed technical results of the wind studies. The data include the year and location of the study, key technical assumptions such as load factor, power rating and lifetime, system boundaries, the type of net energy method used, and the EROI. The table also distinguishes between studies based on actual performance of a wind system and conceptual studies based on theory or simulations.
The average EROI for all studies (operational and conceptual) is 24.6 (n=109; std. dev=22.3). The average EROI for just the operational studies is 18.1 (n=158; std. dev=13.7).
Discussion
EROI and Turbine Size
One of the striking features of the studies is that the EROI generally increases with the power rating of the turbine (Figure 2). This is probably due to several reasons: first, smaller wind turbines represent older, less efficient technologies. The new turbines in the megawatt (MW) range embody many important technical advances that improve the overall effectiveness of energy conversion. Although larger turbines require greater initial energy investments in materials, the increase in power output more than compensates for this.
Figure 2: EROI vs. wind turbine power rating.
Second, larger turbines have a greater rotor diameter, which determines its swept area, which probably is the single most important determinant of a turbine's potential to generate power. A turbine with respectable power rating but a rotor diameter so small that it can't capture that power until the wind speed reaches very high velocities will not produce a reasonable annual energy output. Again, larger rotors require greater initial energy investments in materials, but the increase in power output more than compensates for this.
These conclusions are consistent with the finding that commercial wind farms have moved towards larger turbines that are less expensive with regard to installation, operation, and maintenance. The greater cost efficiency of larger turbines is largely attributed to economies of scale and learning by doing. Accordingly, under a similar assumption, larger turbines have a greater efficiency in respect to EROI.
Another reason that larger turbines have a larger EROI is the well-known "cube rule" of wind power, i.e., that the power available from the wind varies as the cube of the wind speed. Thus, if the wind speed doubles, the power of the wind increases 8 times. New turbines are taller than earlier technologies, and thus extract energy from the higher winds that exist at greater heights. Surface roughness -- roughness determined mainly by the height and type of vegetation and buildings -- reduces wind velocity near the surface. Over flat, open terrain in particular, the wind speed increases relatively fast with height.
Influence of Production Country
EROI is affected by the location of a turbine's manufacture and installation. An anaysis of the EROI of conceptual wind turbines produced and operated in Germany and Brazil shows a range of 5 to 40:1. Such a large range in wind turbine EROIs is a function of differences in the energy used for transportation of manufactured turbines between countries, the countries' economic and energy structure, and recycling policies.
Production and operation of an E-40 turbine, standing 44 meters high in a coastal region in Germany requires approximately 1.39 times more energy, or 3.9 times more input energy per kWh of output energy, than the production and operation of the same turbine in Brazil. This assumes that Brazil's conversion efficiency in the electricity generation system being above 90% is the main reason for the difference in energy inputs, showing that the production scenario has a greater influence upon the magnitude of input energy than site conditions or transportation.
Comparison with other power systems
The EROI for wind turbines compares favorably with other power generation systems (Figure 3). Baseload coal-fired power generation has an EROI between 5 and 10:1. Nuclear power is probably no greater than 5:1, although there is considerable debate regarding how to calculate its EROI. The EROI for hydropower probably exceed 10, but in most places in the world the most favorable sites have been developed.
Figure 3: EROI of various electric power generators.
Challenges facing wind energy
Does the high EROI for wind power presented here guarantee that wind will assume a major role in the world's power generation system? There are a number of issues surrounding wind energy that require resolution before that happens.
The dramatic cost reductions in the manufacture of new wind turbines that characterized the past two decades may be slowing. Part of the slowing may be due to transient factors such as short-term increases in raw material prices; unfavorable exchange rates; insufficient global and domestic manufacturing capability (exacerbated by short-term uncertainty in government subsidy policies); and exercise of market power by the consolidating manufacturing industry. It also is possible that the industry is experiencing diminishing returns to cost reductions via learning-by-doing.
The uncontrolled, intermittent nature of wind reduces its value relative to operator-controlled resources such as coal, gas, or nuclear generation. Intermittency impacts include the seasonal and diurnal match or mis-match to regional energy demands; the contribution of wind energy to capacity reserves for meeting regional reliability requirements; and the lost value to wind plant owners in surplus generation that occurs when wind power saturates the flexible dispatch portion of grid operations.
Wind energy also affects the overall reliability of the electric power system, which is represented in part by the system reserve margin -- that is, a margin of total installed capacity above projected peak load. The capacity credit of an isolated wind plant is generally equal to its capacity factor during the system's peak load period, which normally is less than an operator-controlled source. As more wind capacity is added to a system within a finite geographic area, it becomes increasingly likely that an "outage" at any given facility will be temporally correlated with an "outage" at a nearby (or even not-so nearby) plant. This tends to reduce the average capacity credit for a wind plant as more such facilities are added in a region.
Much of the wind resource base is located in remote locations, so there are costs of getting the wind from the local point-of-generation to a potentially distant load center. This cost is distinct from the cost of simply interconnecting the site to the nearest transmission line. Even at the relatively low current levels of wind penetration on regional grids, long-distance transmission has already proven to be a significant issue for new wind development in some regions. For example, wind plants in Texas have had to curtail output during hours when regional trunk lines are at physical capacity, and Minnesota and California are currently examining ways to alleviate transmission congestion as more development is proposed in their best wind resource areas. These costs are not reflected in most EROI analyses.
The remoteness of the wind resource base also generates the cost of developing land with difficult terrain or that which is increasingly removed from development infrastructure (such as major roads, rivers, or rails capable of transporting the bulky and heavy construction equipment). To the extent that local roads or bridges cannot accommodate blade shipments in excess of 50 meters (over 160 feet) length or nacelle shipments of 50 tons or more, they must be upgraded, rebuilt, or (retroactively) repaired as a part of the plant development process. Little is known about the extent of these costs.
At about 6 or 7 megawatts per square kilometer of net power potential, wind plants are necessarily spread-out over a significant land area. Thus, wind plants must compete with alternative uses of these land resources. In some cases such as agricultural land, multiple simultaneous use is possible. In other cases the competition is stiff. The value of some lands for other types of development (such as urban or housing development) has limited and will limit wind power location options. This is especially true when the land is a signficant source of aesthetic and/or recreational value.
Another issue confronting wind energy is the uncertainty of future government subsidies. Much of the recent growth on wind energy around the world has been made possible by government subsidies such as the wind energy Production Tax Credit (PTC) in the United States and feed-in tariffs and renewable portfolio standards in Europe. While there is strong support in many nations for such support, shifting political winds can create uncertainty for manufacturers and utilities. For example, the wind PTC in the United States was scheduled to expire on December 31, 2005, but was extended to December 31, 2007 by a federal energy bill. The PTC provides a 1.9 cent-per-kilowatt-hour (kWh) tax credit for electricity generated with wind turbines over the first ten years of a project's operations, and is a critical factor in financing new wind farms. The inconsistent nature of this tax credit has been a significant challenge for the wind industry, creating uncertainty for long-term planning and preventing faster market development.
There is also concern about the impacts of wind energy on birds and bats. Early research on the avian impacts of wind energy at places such as Altamont Pass, California, suggested that the wind turbines killed significant numbers of raptors and other birds. In 2004, a large number of bats were killed by a wind farm in West Virginia. The issues surrounding avian and bat mortality have just begun to be studied, so the full potential risk is largely unknown.
Further Reading
- Renewables in Global Energy Supply, International Energy Agency, Paris, 2005.
- M. Lenzen and J. Munksgaard. Energy and CO2 life-cycle analyses of wind turbines-review and applications. Renewable Energy, Volume 26, Number 3, July 2002, pp. 339-362.
- Experience curves for wind energy technology, International Energy Agency, Paris, 2000.
**Citation
Cleveland, Cutler and Ida Kubiszewski. 2006. "Energy return on investment (EROI) for wind energy." Encyclopedia of Earth. Eds. Peter Saundry. (Washington, D.C.: Environmental Information Coalition, National Council for Science and the Environment). [Published October 13, 2006; Retrieved October 14, 2006].
Clearly people are making money (implying high EROIs) on wind. If the concept of oil depletion (as opposed to oil substitution) became more widely understood, perhaps we could generate momentum to use the global wind 'harvest' as a core part of societies future energy portfolio.
Wind gives me hope. But the turbines and parts are built in factories using oil and transported on vehicles using gasoline - so we need to scale quickly. Since wind has a very long economic (and energetic) life, as energy prices increase, built capacity with long life should increase in value (however you measure it) more than a shorter lived energy technology. I think if more people made decisions optimizing energy instead of dollars, the electrical infrastructure might happen on its own.
Im sure the informed reader will note that the average EROI for wind is higher than for new oil/gas exploration. What a clue. Lets get started.
So I'm not sure what kind of solution you are looking for. How large a population do you think can be supported on wind power?
We've got our work cut out for us, for sure. But I see wind as a very hopeful part of that work. Solar, too, of course. I hope tidal has some breakthroughs, too. It's basically a massive form of 'pumped storage'. All these natural sources that are periodic have the rep of being 'inconsistent', but I think that their patterns will start looking a lot more reliable to us, when the curve is clearly on the downslope.
The train issue will be some serious teeth-pulling in the US, which has developed such a strong idea of 'doing it on my own', anything as collective as rail transport threatens a lot of people's sense of 'privacy', I think.
Bob
The short answer, in that Im in Logan Airport, is 'more than I had before'. The longer answer has to do with the electrification of transportation system and a larger baseload for communities from combination wind/solar
I think the confluence of water, energy, and environmental events will one day show that we are near the peak in human population. I will make no predictions of how much smaller it will be in 20-30 years, but irrespective of the number, wind will be a larger part of the energy mix for those people than I originally envisioned.
In a sense, society has been using a one-time subsidy in the form of oil - we now need to wisely use whats left to create systems able to regularly harness a repeating subsidy of solar energy - wind will play the largest part of that. I agree with you that storage tech and backup are issues - at this stage of development if Peak Liquid Fuels is within 5 years then wind wont make much of a difference -if its 10 years out, wind could be huge. The high EROIs of wind basically mean that a hungry society has found a bounty of renewable cows, but as yet does not have milkers, milking machines, buckets or butchers.
And for the record, I have been reasonably freaked out by what I see on the horizon for several years, so please allow me some hopeful angles...:)
It's available in most places, and in the US it's available in all parts of the US. See http://news-service.stanford.edu/news/2005/may25/wind-052505.html
"energy can't be transported long distances very efficiently"
It can be transported pretty far: a quick search found references to 700 mile long transmission lines to California, and 800 km long lines in this discussion: http://www.worldbank.org/html/fpd/em/transmission/technology_abb.pdf
Anyone have more info on transmission distance, esp HVDC?
"don't have good storage technology"
You don't need storage under roughly 15% market share. OTOH, there are some very good storage methods. Alanfrombigeasy has calculated that wind could provide up to 51% of the grid. Alan, could you share the calc's?
"a large network of electric trains"
Electric vehicles are about 8 times more efficient than your average gasoline vehicle (1,600 watt-hours/mile vs 200 whrs/mile), and actually more efficient than electric trains (though electric trains have other benefits, like supporting urban living).
" the little problem of food production when fossil fuels decline"
Tractors can be electric. Fertilizer is a small % of FF use, and could come from biomass.
"How large a population do you think can be supported on wind power?"
All of it. See the first reference above. OTOH, that would be an expensive way to go. Much better would be a mix of wind, solar, hydro, biomass, wave, etc.
What are the 'very good storage methods'?
I seem to remember pumped storage being about $50/kwh in today's dollars for the Racoon Mountain system, and flow batteries costing around 3-4x that in large installations (though they aren't site-limited).
HVDC seems to be an evolutionary improvement, rather than a disruptive technology, over HVAC - around 5% loss per 1000km rather than around 8%. Land use is much lower, but the loss improvements are nothing compared to, say, HTSC lines. HVDC is naturally suited to large-capacity dynamic load balancing (as slow transformers don't need to be involved) and DC power sources like solar.
IMO, even removing a 20% loss to the farthest parts of the country won't suddenly make a particular technology viable - We CAN move power long distances efficiently with current technology. Though being able to pack 3x the conductors into the same right of way in urban areas (without ELF health nuts) might help.
The question I was answering was: could the grid support the replacement of all light duty (cars, SUV's, pickups) gasoline vehicles with EV's? I used efficient EV's (Tesla) and HEV's (Prius) and compared them to the current fleet average. The comparison helps answer the intuitive question: "isn't that a lot of energy for the grid to supply?" The answer is that it's not really as much energy as you might expect. OTOH, if you compared within the same class of aerodynamics chassis the ratio might be 4-6:1.
The Tesla uses 215 wh/mile, outlet to wheel, and it's optimized for speed, not efficiency.
"What are the 'very good storage methods'?"
I'm mostly thinking of the same things: off-setting hydro, pumped storage, flow batteries, EV planned charging and Vehicle to Grid. "very good" might have been a little strong - "good enough" is probably better, though Alan feels very strongly about the effectiveness of hydro & pumped storage, and I think PHEV & EV's will be very, very useful.
If I understand you, you feel that if wind is otherwise viable that transmission won't be a barrier to it's use. Is that right?
That sending your solar produced in Texas to Los Angeles probably has less of of an energy footprint than storing it in pumped storage in Texas for later use in Dallas is helpful.
A good portion of industrial use can be tempered to low-usage times. Smelters don't have to operate at 4:30pm when everyone at once turns on their AC. That and EV planned seem like they'd have a lot bigger effect than vehicle to grid, which is hopelessly decentralized + inconveniant IMO.
OTOH, these days cars are pretty much computers that happen to have wheels, and communication & control through intelligent meters might not be difficult to do in the long run. Things will change a great deal in the next couple of decades, I think.
I meant household demand management & time shifting. Though I have seen somebody use a Prius as a household UPS....
Actually, many industrial processes require continuous control. Thermal cycling of the insulation in a smelter is bad; blast furnaces are often rebuilt after each shutdown.
Many commentators consider decentralization a virtue.
Shifting charging demand over to certain times is much, much easier. It's trivial and self-regulating to setup a wifi or wimax network and send out an expected power price over time chart, then have a locally smart charger fill that up with the cheapest juice.
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I wasn't really talking about short-term demand, though I guess I'm a bit out of my league here. Would changing the standard electricity-intensive heavy industry worker over to a night shift be possible as a means of deflecting demand from peak periods?
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Sorry I was rather vague in the first statement - I should have stuck to wind capacity. A ~10% or so average hit in transmission costs from the nearest rural area populated with wind turbines is nothing, compared to the many thousands of percent that would be needed to shift most of our energy production over to wind turbines.
It means that yes, if we wanted to we could built an underwater nuclear complex in the center of the south pacific thousands of miles from the nearest human, and shift over all the energy to our homes at a cost of increasing the complex size by a paltry 50% or so over what we could build right here.
hi
why is the synchronization at 60 Hz with system wide phase coherence difficult ?
i'm worked on R&D teams where phase locked loops were up in the 200 MHz ballpark.
there's got to be a way to synchronize phase at 60 Hz.
wwswimming
at
yahoo.com
Your cost estimates are WAY off. With no economic value attached to GW today, the zero GHG grid that I proposed would likely raise rates 50% to 75% (which would happen anyway).
A steady rise in carbon taxes would push us towards that sort of grid anyway (nukes need pumped storage as well to neet anything more than peak load). Depending on costs associated with nukes (remember costs of the last dozen finished in the US, and the new Finnish one seems in trouble early) and just how steep the decline is in WTs and other renewable costs (WT electricity will be cheaper in 2012 than today, Not so for nuke) the mix will be somewhere between 23% nuke and ~/2.3rds nuke on strictly economics alone.
More than 2/3rds nuke begins to run into significant problems. France is able to get up to 90% nuke becasue they sell power all night long to ALL of their neighbors. Swiss utilites buy night power from several French nukes and save their water for selling back to the French, Germans, Italians at peak (at 3 to 5 times the price). Perhaps we can do the same with Canada.
Also nuke is VERY risky to build a society on because of common design flaws. Any design can have a hidden flaw, which, when discovered, requires shutting down ALL reactors of that type for months tp years. It has happened several times already and will happen again. No one reactor type should IMHO supply more than 4% of national power. Unexpectedly losing 4% of your generation is a blow, but it can be worked around with luck. More than 4% ? Nope.
EP, I'm surprised at your emphasis here. A LOT of industrial power is shifted to the night to take advantage of lower rates. Heck, I have a steel mill a mile from my home that shifts into overdrive at night...
You are talking about a major societal transformation here for wind power to make any impact on mitigating the fossil fuel crisis. And peak oil is within five years?
It's too late for this.
We're there now. Wind is supplying 43% of planned new generation in 2007 in the US. It can easily ramp up to supply all new demand growth (2% per year) within 5 years. Wind can handle demand growth replacement of existing plants that are planned for replacement, and substitution for depleting nat gas if we made a modest societal commitment to using it to the exclusion of coal. Actually replacing existing power plants before their planned end-of-life, and replacing existing coal usage are more difficult questions: those would be expensive, and require a major societal commitment that we're not yet close to.
"How many years and how much money would that take? "
Keep in mind that we don't have to replace all 210M vehicles: newer vehicles get much higher useage (something Hirsch didn't take into account), and there are only 100M households. Probably 5 years US vehicle production (85M vehicles) could replace 60% of miles driven.
There are two different questions: is there enough power for the grid, and is there enough portable power for transportation. I think unquestionably the grid will be ok with only relatively modest investments in infrastructure. Transportation? That could be painful. There will certainly be enough for key needs such as transporting wind turbines, but visiting mom in Florida, or commuting to distant low wage jobs, may get expensive.
To me that says wind has "arrived". What do you think?
Wind at 100% of power generation in 40 years? No way. Remember, in the US wind competes against baseload coal, gas, hydro and nuclear. System operators look at the *relative* value and cost when they dispatch power. Coal is abundant and cheap. Gas is less abundant but also pretty cheap. Wind is also cheap in terms of operating cost, but it is a not under operator control and is variable based on weather conditions. From the system opeators this reduces the value of wind energy, it reduces its contribution to reserve margins that are dictated by regulations, and it reduces the
value to wind plant owners in surplus generation that occurs when wind power saturates the flexible dispatch portion of grid operations.
These are not insurmountable prolems, but they are formidable barriers.
The EIA wind experts told me that if the 1.9 cent production tax credit goes away, wind energy goes into a deep stasis in the US. What does that say about its viability?
I suppose it really would make more sense to figure the EROI of a 'black box' which delivers the amounts of energy we want when it is needed. Within the 'black box' would be a mix of wind, solar, nuclear, etc. It may be useful for starters to have the figures for individual sources, but real world applications need more complex analyses.
Cutler, you have been in this business for a while. Do you know of anyone who has done, even on an abstract level, this type of 'composite' EROI analysis? I suspect it might surprise us that the mix could be far better than the individual sources. Whole greater than the sum and all that.
In 1992 such a wind farm would cost 200 million dollars, which doesn't include labor and maintenance costs, and would serve less than one percent of the United States population. It would cost over $200,000,000,000 to build enough windmills to generate electrical power for everyone (though of course, you couldn't, since not all areas have enough wind). With energy prices many times higher now than in 1992, the cost would be far more expensive.
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Summary of Sergio Pacca and Darpa Horvath 2002 Greenhouse Gas Emissions from Building and Operating Electric Power Plants in the Upper Colorado River Basin
ENVIRONMENTAL SCIENCE & TECHNOLOGY / VOL. 36, NO. 14 pp. 3194-3200
There is a large area of research devoted to figuring out how much material, energy, and cost is required to build various types of power plants. To estimate the overall greenhouse gas (GHG) emissions over the life cycle of a plant, Pacca and Horvath used Life Cycle Assessment (LCA), a method that calculates materials extraction, manufacturing and production, operations, and the disposal of the materials at the end of the life of the power plant.
As you can imagine, this isn't easy. There are two main LCA models -- Pacca and Horvath chose the EIOLCA approach, which uses a large commodity matrix that tries to identify the entire chain of suppliers of the raw materials, and then this matrix is multiplied by another one containing emissions and energy use per dollar.
Because dollars fluctuate in value, a better method would be to calculate the energy used at every step of the chain, but still, these dollar amounts give a rough idea of the embedded energy.
The study compares the Glen Canyon dam with four other types of power plants, all figures are scaled to each plant producing 5.55 TWh of energy per year.
This kind of study could help decide which direction a future energy Manhattan project should. This study rules out a Photovoltaic power plant, which is not possible now -- it requires 4118 MW of power, but the total world production of PV modules up to 1997 was only 125 MW, less than 3% of what's required for just this one plant. The PV plant also displaces an enormous ecosystem, about 20 square miles.
This study does not cover nuclear power plants. Another study states "nuclear fission energy requires small inputs of natural resources compared to most other fossil and non-fossil energy technologies. When we consider net electricity generation (e.g., net electricity after subtracting consumption by internal plant loads and by uranium enrichment plants), the life-cycle resource inputs for non-fossil power sources are dominated by construction materials, most notably steel and concrete. The construction of existing 1970-vintage U.S. nuclear power plants required 40 metric tons (MT) of steel and 190 cubic meters (m3) of concrete per average megawatt of electricity (MW(e)) generating capacity. For comparison, a typical wind energy system operating with 6.5 meters-per-second average wind speed requires construction inputs of 460 MT of steel and 870 m3 of concrete per average MW(e). Coal uses 98 MT of steel and 160 m3 of concrete per average MW(e); & natural-gas combined cycle plants use 3.3 MT steel and 27 m3 concrete" (1).
Below are two tables summarizing the data.
GWE: Global Warming Effect is the Greenhouse Gas (GHG) emissions in MegaTons of CO2 equivalent, which is calculated by adding CO2 + CH4 +N2O together
MT = MegaTon = 1,000,000 Metric tons. 1 MT = 2,204.62262 pounds
Here's just wind since it didn't format properly below:
Wind
Construction Farm
Input Total MT
--------------- ---------
aluminum.............6,275
cement
concrete.........1,266,172
copper.............. 1,569
electricity MWh..1,691,678
excavation m3
glass................4,930
oil....................448
plastics............20,169
sand.................9,412
steel..............289,987
(1) Peterson, P. F. Will the United States Need a Second Geologic Repository? The Bridge 2003, 33 (3), 26-32.
TABLE 1: COMPARISON OF INPUTS
Hydro PV Wind Coal Nat Gas
Construction Plant Plant Farm Plant Plant
Input Total MT Total MT Total MT Total MT TOTAL MT
--------------- --------- --------- -------- -------- --------
aluminum 67 177,788 6,275 624 230
cement 2,222,356
concrete 9.906.809 1,266,172 178,320 71,270
copper 90 480,029 1,569
electricity MWh 7,556,010 1,691,678
excavation m3 4,711,405
glass 1,066,731 4,930
oil 448
plastics 20,169
sand 9,412
steel 32,183 4,600,276 289,987 62,200 51,130
Operational Inputs
------------------
coal combustion 2,336,000
coal extraction 2,336,000
transportation by railroad 2,336,000
natural gas combustion 1,560,300,000 m3
natural gas transportation 1,560,300,000 m3
natural gas extraction 1,560,300,000 m3
TABLE 2: COST, GWE (Global Warming Effect), and Area required
Total Cost Area
(1992 $) GWE required
----------- ------- --------------
Coal Power Plant 149,772,446 90,000,000 n/a
Wind Farm 206,881,416 800,000 489,580,000 m2
Natural Gas Plant 374,033,481 50,000,000 n/a
Hydroelectric Dam 503,240,216 500,000 651,141,400 m2
Photovoltaic Plant 3,578,457,990 10,000,000 51,386,400 m2
NOTE: the cost in 1992 dollars doesn't include labor, installation, or maintenance costs.
Photovoltaic Plant 100-W panels of dimensions 1.316 x 0.66 m with array units of 3 x 10 panels, each having its own concrete foundation, for a surface area of 3.9 x 6.6 m, sited at 30° latitude, at a 30-deg tilt (approximately 1.2 m of additional width is needed to account for shading by the array due to the sun's angle). There is 0.9 m between each of these array units for personnel access. Each adjacent unit covers a land area of 37.44 m2 and has a capacity rating of 3 kW. Some 1,372,500 of these 3 kW units are required.
Wind Farm location: Southern Utah, at 7,000 feet. average windspeed 6.5 m/s turbine: 600 kW in 4480 turbines
Hydropower: As the U.S. Bureau of Reclamation has suggested, "upgrading hydroelectric generator and turbine units at existing power plants is one of the most immediate, cost-effective, and environmentally acceptable means for developing additional electrical power".
Modern turbines are c. 1MW (1000kw).
4480 turbines of 660KW.
I had trouble with the units in what you posted, but 2.8 trillion pounds of contcrete is
2.8X10EE12 pounds of concrete
or 1.27 X 10EE12 kgs of concrete
or 1.27 X 10EE9 tonnes of concrete
or 283,482 tonnes of concrete per turbine?
That is basically as much concrete, per turbine, as you would use to build a substantial skyscraper.
That number looks really wrong. Similar for all the other raw materials numbers quoted.
Just on Load Factor, for any power plant it means the per cent. of the rated capacity you will achieve.
So for a wind turbine, 30% means 30% of the time it will blow at 100% of rated capacity, or 100% of the time it will produce at 30% of rated capacity.
Nukes typically run in the low 80s (distorted a bit by the fact that every few years they have a complete maintenance shutdown). All other power stations run below that level (because nuclear and hydro produce most of the baseload).
My own calculations from the problem set above
5.500 TWhr = 0.1% ish of US power consumption
5500 GWhr requires 6278MW of capacity at 100% Load Factor (divide by 8760 hrs pa)
So therefore at 0.3 LF 20,926 1 MW turbines (actually 1.2-1.4MW/ turbine is more like it).
Cost would be about $20bn.
Cost to do that in nuclear would be about $16bn (assuming 3rd Gen technology ie 4X1650MW units at $4bn each) + whatever price you care to put on waste disposal and long term decommissioning. Gas or coal would be less than $10bn but you would then have fuel cost.
So if you did that 800 times you would cover the entire US power consumption. For $1.6 trillion. Which is about 15% of US GDP now, or about equal to what the US spends on fixed commercial assets every year (capital spending by companies).
So over 20 years, 5% of US capital spending to cover the entire US energy consumption.
The estimated total cost of the war in Iraq is between 1 and $2 trillion (that was actually a 2004 estimate, so I am assuming the current costs of $15bn a month or so are offset by no rise in future costs).
Now there are a few other factors: depreciation (but that affects the turbines much more than the structures), growth in power demand (however GDP would also grow), the fact that you wouldn't use wind for all that capacity (because of grid issues).
But it's a measure of what one can achieve.
http://www.progressiveengineer.com/PEWebBackissues2002/PEWeb%2028%20Jul%2002-2/Wind.htm
If concrete weighs about 100 pounds/cubic foot * 27
= 2700 lbs/cubic yard
200 cubic yards times 2700 pounds = 540,000 lbs
540,000 / 2,000 = 270 tons per windmill foundation
270 tons times 4480 windmills = 1,209,600 tons for this windmill farm, which is within 5% of what Pacca and Horvath use (1,266,172)
Here is what their paper had to say about windmills:
A wind farm producing 5.55 TWh of electricity per year was assumed to be in southern Utah, at an elevation of 2134 m (7000 ft), close to the Escalante Desert where the average wind speed is 6.5 m/s (35). A turbine of 600 kW (36) was used as the unit for the farm's total of 4480 turbines that would occupy an area of 489 580 000 m2 (37). The total cost of materials and construction of the facility would amount to $206,881,000 (in 1992 dollars) without labor/installation and maintenance costs. Given a range of prices between $250 and $1200 per ha, the required land would add an additional $12,000,000-59,000,000 to the cost. Given the large area, land between the turbines could be used for other activities such as agriculture. No NEP loss was anticipated. The contribution of construction materials and energy to theGWE of the wind farm after 20 yr of operation (800 000 MT of CO2 equiv) is shown in Table 3.
It was assumed that after 20 yr of operation all turbines had to be replaced (but not the concrete foundations) and that the required construction energy was 30% of the original electricity and 100% of petroleum used. The electricity output of the facility remained constant. The refurbishment resulted in 900,000 MT of CO2 emissions, two-thirds of the original emissions from manufacturing and constructing the plant (1,300,000 MT of CO2).
Any 1992 wind turbine data is of historical interest only. Simply not relevant to today or, even more, tomorrow.
Alan
Second, either something is seriously wrong with this study, or wind was already a lot cheaper in 1992 than any other source of electricity: 5.55 TWhr per year, at $.10/kwhr, is worth $555 million. If this windfarm costs $200 million, then that's a 4 month payback and a return on investment of about 300% per year. In other words, this windfarm would have generated electricity at a cost of about a half penny per kwhr.
It's called a negative externality in economics.
Essentially we allow polluters to pollute without restriction, the most dangerous industrial pollutant of all-- the one that could trigger the end of human life on this planet (or, more likely, make our current civilisation unsustainable).
If you charge $100/tonne for Carbon emissions ($28 per tonne of CO2) the economics of coal look very different. European permit prices under the emissions trading scheme have reached those kinds of levels.
There is actually no economic case for allowing coal fired power, without carbon sequestration, given the potential damage of those CO2 emissions.
The fossil fuel industry, world wide, is a major recipient of government subsidies, implicit or explicit. From the destruction of natural habitats for which there are tax allowances for any restorative work (or the work is just not done) through to the high human cost of an industry with a very high mortality rate. (I won't mention lung cancer from particulates emission).
The nuclear industry is itself the recipient of massive government subsidies. The Price Anderson Act provides insurance which would not be available in private markets, limiting the liability in the case of an accident. The R&D was paid for by governments. The future waste storage liability is undertaken by governments when we have a solution.
No nuclear utility operates in a pure 'merchant power' context. British Energy tried, selling into the pool, and when the pool price crashed, it went broke and the government had to stump up £3.5bn to refinance it (to prevent a renationalisation).
Nuclear utilities across the world are either state controlled or have arrangements with the regulators that allow their cost of production to be loaded onto the consumer (effectively a guaranteed floor price).
The Bush Energy Act and the proposed British nuclear restart both provide for explicit price subsidies for new nuclear facilities.
The UK decommissioning liability for existing nuclear plants is £70bn present value.
The EIA wind experts told me that if the 1.9 cent production tax credit goes away, wind energy goes into a deep stasis in the US. What does that say about its viability
Golly Geee. What happens to Nuclear fission if Price -Anderson were to "go away"?
Looks like one of your 'base loads' is not viable without that government handout.
If there was no 'protection' like with Price-Anderson , there would be no commericial fission power generation. Given how well the saftey net of government has re-build the WTC complex and helpped the people of New Orleans .....would the government help the people who would be effected by a fission failure, or just say 'too bad'?
What is the EROEI of fission failure? What is the EROEI on the failure of a wind machine?
Now certainly this might be construed as an insurance subsidy, but we cant conclude that commercial fission power wouldn't exist in the US without it. Specifically:
"According to the United States Public Interest Research Group the subsidy to the nuclear industry has been estimated at between $366 million and $3.5 billion annually, or $3.5 million to $33 million per reactor per year"
Which is certainly affordable on the lower end. Even without this protection, the risk to an individual reactor of a major accident is so low, it might simply be prudent to run naked of insurance.
At best, this is in the realm of specualtion, unless you have citations that indicate no insurance provider will cover nuclear power plants.
http://en.wikipedia.org/wiki/Price-Anderson_Act
"At the time of the Act's passing, it was considered necessary as an incentive for the private production of nuclear energy. This was because investors were unwilling to accept the then-unknown risks of nuclear energy without limitations on their liability."
After all, in most countries, the government owns the utilities, or they are so tightly regulated as to be de facto government entities.
The government also guarantees the price the nuclear generator receives-- when the Pool price plummeted in the UK, British Energy, the privatised nuclear operator, defaulted on its loans. The government had to step in and bail it out to the tune of £3.5bn.
No insurer would sign on to an unlimited liability for nuclear power. It would be another asbestos death spiral.
Remember the liability for nuclear power will run to hundreds of years.
Nuke owners maintain private liability insurance plus have a big risk pool arrangement. These two private pools covered the public liabilities for the Three Mile Island neighbors and those were exclusively for evacuation costs and some "mental anguish" cases. Owners also have some "comprehensive" coverage for their own assets.
If you do not maintain insurance coverage, the NRC will lift your license and you will be shutdown.
For as long as I can remember, the nukes I've worked at have gotten full premium refunds - with interest.
See http://www.nrc.gov/reading-rm/doc-collections/fact-sheets/funds-fs.html
Price-Anderson says, to me, more about the economic inefficiencies of American tort law than about nuclear safety. Any company doing any nuclear work demands some limitation on private liability since without it, a contract is "you bet your company."
http://en.wikipedia.org/wiki/Price-Anderson_Nuclear_Industries_Indemnity_Act
"Since Price-Anderson was enacted, nuclear insurance pools have paid out some $151 million"
Price-Anderson says, to me, more about the economic inefficiencies of American tort law than about nuclear safety.
And yet, if the cost of the failure modes were not so high, the law would not be in place.
If oyu feel the fission industry is so safe, then by all means ask for Price-Anderson to be repealed.
http://www.greenscissors.org/energy/price-anderson.htm
In fact, have the fission industry pay for its protection from the terrorists that the citizens are being told lurk around every corner and are waiting to attack a plant. Surly, if fission is so safe, the payments to the military and other security measures should still keep fission power cheap....right?
Paying to protect from terror, paying the full insurance rates, AND paying for long-term dispoasl of waste should be cheaper than the payments to The Government....and be more effective....right?
Oh, and be sure to include the cost of moving the 'entombed disposal' to dry land when sea waters rise due to global warming.
The fact remains that NO member of the public in the US has EVER been over-exposed from a civilian nuclear power plant.
Please, let's keep our facts straight.
Taxes paid by all citizens provide for the common defense. That remains the Federal government's responsibility to ALL citizens.
Individual nuclear plants employ extensive armed guards and security equipment. Meeting Federal regulations are the responsibility of the owners. That is a cost of doing business.
I'm no lawyer but American tort law infamously reaches into the deepest pocket for any portion of shared liability.
The notion of how catastrophic a nuclear accident might be was first estimated in the late 50's and it was intended to be bounding. Fifty years of research into severe accidents have shown that off-site consequences are much, much less severe than previously thought.
Relatively small enhancements have made huge reductions in risk. For example, the concrete under the TMI reactor vessel was made of crushed limestone as the aggregates. "Core on the floor" scenarios (beyond the TMI event) would cause its decomposition into non-condensable gases which overpressurize and fail containment.
My new reactor has a 5 foot thick layer of alumina refractory under the core so that a meltdown would be contained and stopped - no more China Syndrome and no containment failure. No containment failure means no off-site consequences.
There have been calls to reform tort law but the trial lawyers have successfully block them. Make the general reforms and we can rethink Price Anderson. Besides, once Congress confers a benefit, it is really hard to take it away.
So you are claiming that these payouts were not under the Price-Anderson and follow-up laws?
Exactly HOW is that possible, given the law is what influences the policies that exist.
If there are no payouts underthe law, then why have the law?
The fact remains that NO member of the public in the US has EVER been over-exposed from a civilian nuclear power plant.
This is your answer to the question about the risks of having a fission reactor? Why are you limiting the DEMONSTRATED downside ERORI costs of fission to just the US of A?
Is your next position going to be to bring the US of A government, regulation and engineering to other lands so this safty you are claiming can be everyones?
Taxes paid by all citizens provide for the common defense. That remains the Federal government's responsibility to ALL citizens.
Interesting position. Corporations are citizens. And if some citizen creates more risk, ENYERONE has to pay VS that citizen paying for the risk they are creating.
Looks like taking money from the common good to benefit the 'citzen' with the fission reactor.
Meeting Federal regulations are the responsibility of the owners.
Don't the regs exist to provide safety? If so, why do all these 'safe' places keep paying fines for not following the fed regs?
Make the general reforms and we can rethink Price Anderson.
Price Anderson exists because fission is risky. You are claiming there is no risk - so trying to claim 'tort reform' makes it look like you don't really believe in your safety message.
Besides, as you've stated "I'm no lawyer " and you ARE claiming you know all about how safe fission is.
My new reactor has a 5 foot thick layer of alumina refractory under the core so that a meltdown would be contained and stopped - no more China Syndrome and no containment failure. No containment failure means no off-site consequences.
And hows that design gonna work on the coasts and the coasts go underwater with sea level rising? I noticed how you ignored the EROEI of taking the entombed reactors along the coast and moving them to high ground if the water rises.
You're going off the deep end in your post about rising sea levels.
To clarify the insurance issue, nuke owners maintain private insurance, much like automobile comprehensive, that covers public liability and their own equipment. The amount of liability is capped at some big number, maybe $500,000,000 - I don't have that figure at my fingertips. This is because insurance pools want to limit any on-time hit. There is just not a much bigger market of liquid capital for insurance. The payouts in wikipedia you linked to came from this private insurance pool.
The payouts for the evacuees at TMI for temporary housing and "mental distress" came from the private insurers and hence from the premiums paid by the owners.
Above and beyond the capacity of the private insurance pools comes government insurance for liability in the form of Price-Anderson. There have been no claims against the government Price-Anderson coverage. There would be private liability insurance for some level of coverage whether or not Price-Anderson was in effect.
Put it another way, it is a put held by the nuclear industry against the government.
It has infinite time value. If you look at any option pricing textbook, even an out of the money put has a monetary value.
Would Warren Buffet issue a 'cat' bond (a bond which only pays out on a certain, low probability event) against the nuclear industry? I don't think so. He is very averse to open ended risks.
On sea levels and nuclear reactors the problem has already come up.
The UK wants to license new reactors on existing sites where there were operating stations, however the Department of the Environment has pointed out to the Government that many of those sites may be underwater by 2050.
The other GW impact on nuclear has been the super hot summers we have been having. The French have had to shut units down, because there was not enough cooling water in the rivers. tant pis, as they say.
If a jury finds that a company is 10% liable for an accident (of any kind), the"deep pockets" can wind up paying 100% of the damages plus "pain and suffering" plus attorneys' fees.
I won't say that Price-Anderson is essential to the continued health of the nuclear industry but I don't expect it to go away since arguments otherwise are not compelling.
It's not an unknown principle, for example the UK government insures major art exhibits. Without such insurance, there is no way Old Master paintings (of the quality of a major art museum) would ever be exhibited in the UK (the cost of a theft or a fire could easily be £500m+).
But it's wrong to say it is not a cost. It is a Put Option, held by the future claimants in a nuclear accident, against the UK (or US) taxpayer.
That Put Option has value, because it has infinite time value (the volatility is unknown). Even though it is 'out of the money' (not exercisable).
In addition, markets have made it clear they will not finance new nuclear facilities unless the power price is guaranteed. No utility would build such capacity (the Finnish government negotiated long term power contracts wiht big industrial users):
You say its required, I say it isn't. Open your company as an LLC and be done with it. Bet your company and you'll be fine.
Given the thousands of reactor years of experience, its a safe bet. And stop erecting the strawman of implying Price-Anderson as a subsidy without cost.
It does offer some perceived shareholder value and its retirement would probably cause some slight downward pressure on stock prices.
Would the nuclear industry go on without it? Probably but I'm a bit of a traitor to say so.
BTW, that's about 10,000 reactor-years of experience for LWRs.
hmm. I'm not sure if anybody is suggesting that - certainly not me. Alan, I and other posters have been suggesting that the optimal mix for wind in the longterm is likely between around 20% and 55%.
"The EIA wind experts told me that if the 1.9 cent production tax credit goes away, wind energy goes into a deep stasis in the US"
Are they really wind experts? It's easy to take a superficial look at the relationship between wind investment and the credit in recent years and assume that the credit is necessary.
I would argue that even if wind was competitive price-wise that any sane developer would delay construction if the PTC had expired in the current year, and there was a reasonable expectation of it being revived in the next year - why get a modest ROI if you can wait 6 months and get a greate ROI?
Finally, would you agree that it's likely that natural gas prices will continue to rise, and there is a pretty good chance of some sort of carbon tax or trading system that will reward wind and penalize coal?
What would you estimate as current costs for coal and wind as a rough average?
Let me take a different approach. What I'm saying is that I think that even without subsidies wind was cheaper than natural gas generation for a while this last year, and it's likely be cheaper again for the longterm as gas production declines, and prices rise again. Further, carbon taxes and/or CO2 sequestration, combined with continued declines in wind costs will (if GW is the threat it seems to be) in the long term likely make wind cheaper than coal.
What do you think?
I am sorry, but ... give a subsidy and they will come.
"Another issue confronting wind energy is the uncertainty of future government subsidies. Much of the recent growth on wind energy around the world has been made possible by government subsidies such as the wind energy Production Tax Credit (PTC) in the United States and feed-in tariffs and renewable portfolio standards in Europe. While there is strong support in many nations for such support, shifting political winds can create uncertainty for manufacturers and utilities."
If you believe in Peak Oil, then you believe in Peak Gas, and you believe that US gas prices won't fall below some threshold, long run.
(at the very least, given the depletion curves for US and Canadian gas, US gas prices long term won't fall below the $6/mcf entry price for LNG if the LNG facilities can get built in time. At that point, wind is not cheaper than gas, but certainly within spitting range, or rather some wind is cheaper than some CCGT).
The case for wind is the same one as the case for nuclear, which is
- the capital cost is high
- with lower real interest rates, the capital cost falls (more dramatic effect for nuclear since they take much longer to build)
- the fuel cost is very low (free in the case of wind) and the operating costs should be low (they've never quite made it in nuclear)
- the CO2 output is negligible (again a little more tendentious for nukes, because of the mining and reprocessing cycle)
We can't feasibly run an entire grid on wind without some new departures in energy storage technology.Conversely we can certainly supply 20% of our Terrawatt Hrs from wind (US or UK) and if we practice active demand management to smooth the load curve, significantly reduce the CO2 emissions from our electric power system.
No. You can't "run the grid" the way people have been USED TO. The level of service you are used to (throw the switch and stuff works) and the pricing (same rate no matter if it the middle of the night or in 120 deg F heat, or if the wind is blowing brisk and the grid has excessive load) will change.
A 'wind doesn't work' position is looking from the lens of 'we have to keep what we are used to'. Guess what? There's gonna be some changes m