Minnesotans For Sustainability©
Sustainable: A society that balances the environment, other life forms, and human interactions over an indefinite time period.
Net Energy from Nuclear Power
Gene Tyner, Sr.1*
This paper is a continuation of prior efforts to estimate net-energy yield of nuclear power in the United States.2 Additional details and explanations are included in the appendix below.
The Bush-Cheney Administration, perhaps recognizing that there is not enough oil and gas to continue economic growth, is considering a massive nuclear-power construction program along with other initiatives, in hopes of alleviating future energy shortages. It is important that we clearly understand whether this will result in added energy supply or merely divert massive quantities of fossil fuels to an effort with small or negative long-term results and, perhaps, exacerbate the short-term energy problem.
In this paper the relationship between Energy Consumption and Gross Domestic Product is used as a surrogate to estimate the amount of Energy Required to Get Energy (Net Energy) – or as some others have termed Energy Return On Investment (EROI.) It is a relatively simple procedure: (1) Estimate Lifecycle System Cost (LSC) of an energy-transformation system, (2) Multiply LSC times a selected ratio of annual energy consumption (E) to annual consumption of Gross Domestic Product (GDP,) and (3) Compare the result to the expected energy output from the energy system under consideration.
In the current study a complete nuclear-power system is analyzed, including construction of all plant, including transmission and distribution plant, lifecycle operation and maintenance, fuel, and finally disposition of residual wastes after the plant has been retired.
Table 1 is exemplary of how this methodology works out for Total U.S. Energy Consumption for selected years from 1980 to 1995. Total energy consumed is known. Total consumption in Btu’s is multiplied times the average cost per Btu. (Mil Btu. Avg.) in order to estimate the amount of energy required to mine, transform and deliver the energy to final users of the energy.
It was striking to find that the “% Available” energy is uniformly 89-90% for the selected years with an average Output/Input ratio of approximately 9 to 1.
It is argued that a complete net energy analysis should estimate the capability of the energy‑transformation entity to continuously sustain and reproduce itself from it's own output and leave a sufficient residual for the rest of society to enjoy a comparable level of economic welfare as the energy producers.
The model proposed in this paper assumes that all money payments made by the energy‑transformation systems are essential to the system's existence. It is argued that there is a direct, although approximate, relationship between monies paid and energy consumed. This relationship offers a more comprehensive departure point for estimating the Net Energy to be expected from energy‑transformation systems than can be obtained in energy analysis (except for Odum's eMergy Analysis.)4 The ratio of Annual Energy Consumption (E) and Annual Gross Domestic Product (GDP), i.e. the E/GDP Ratio, is an approximation of how much energy, on average, is depleted to produce one dollar of GDP.
Figure 1 indicates that less is required in recent years than before. Increased efficiency accounts for part of this drift but Cleveland and Kaufman attribute most of it to energy‑quality changes.5
The reasoning of standard economists has dominated the world perspective on future energy supply, and hence energy policy, or lack thereof. On the demand side, it may be correct to reason that rising energy prices may alter human behavior to behave differently, such as conservation or change in lifestyle. On the supply side, however, standard economic theory holds that if any good is in short supply (and many standard economists regard energy as another ordinary good,) rising prices will trigger entrepreneurial ingenuity to provide an additional supply of the same good or an acceptable substitute. While this is acceptable reasoning for ordinary goods (as long as energy and resources are available,) energy is not an ordinary good. Various energy forms (petroleum, natural gas, wood, electricity etc.) are somewhat substitutable for each other, but nothing can substitute for energy, per se. Finally, ordinary goods can only be made available by depleting some form of energy. It takes energy to get energy. Standard economists appear to not worry about energy or resource depletion because of their faith in markets to solve all shortage problems. This seems more like religion than science.
The First Law of Economics should be: Goods and services cannot be made available unless energy is depleted. The existing tools, factories, infrastructure and housing stock of the current civilization, including energy transformation and distribution systems, was initially put in place with relatively cheap and abundant energy (energy with a high net‑energy yield.) As rich fossil‑fuel stocks are depleted, more energy is needed to get energy, consequently, relatively less will be available for production of other goods and services. Cleveland and Kaufman have estimated the "Net‑Energy From the Extraction of Oil and Gas in the United States, 1954‑1957.6
Energy‑acquisitions systems also enjoy the benefits of the in‑place infrastructure of society. The existing U.S. infrastructure set (waterways, railways, roadways, ad infinitum, capital‑in‑place, and housing stock, highway, airway, waterway systems, ad infinitum) gradually deteriorates and requires replacement. Replacements require further energy depletion and as time passes, sources with less net energy will be available to do this. Since infrastructure serves energy‑acquisition systems, it seems reasonable to assume that net‑energy yield will decline accordingly (and more gross energy will be required to produce a dollar of GDP.) Of course, as society accumulates information, we may learn to use energy and materials more efficiently, but all efforts to increase efficiency are not without an energy cost of achieving that efficiency. Recycling, although a reasonable practice is only achieved by an input of energy and materials.
Further, the current set of energy types (coal, natural gas, petroleum, etc.) has a corresponding set of endusing technologies (automobiles, ships, trains, automobiles, aircraft, manufacturing and communications systems, space‑heating systems, ad infinitum.) Adapting to a new form of energy —say an all‑electric system— requires a different set of end‑user equipments. Much energy would be required to make such transition (s).
Despite relatively low prices of current energy supply, it is clear that world fossil‑fuel supplies will ultimately be depleted to a point where it is no longer practical to mine them. More energy will be required for recovery and transformation than can be realized from them. M. King Hubbert estimated that about 80% of world petroleum supply would be consumed between 1960 and 2030; 80% of natural gas between 1934 and 1999; and 80% of coal between 2000 and 2300. In 1976, Fowler revised and extended this analysis with similar conclusions. Duncan has placed the peak of per‑capita energy production as 1979 that has precipitously declined from 1979 to 1999.7 Colin Campbell provides an updated Hubbert‑Type of discussion.8
Some standard economists explicitly held that capital could be substituted for energy. While this is true for individual activities,9 capital is only made available in the overall system by a corresponding depletion of some form of energy and materials and therefore, substitution of an alternate good for energy does not really occur in a broad sense. Energy is an extra‑ordinary, essential substance having unique properties for which there is no substitute.10
Figure 2 depicts Total‑Energy Consumption, Energy‑System Losses, and End‑Use Consumption froml973 to 2000. It should be noted that End Use is approximately 75% of total consumption.
Figure 2 ‑ U.S. Energy Disposition
Figure 3 -Energy Flow
The "Cost times E/GDP" approach is as follows:
(1) Estimate the total lifecycle monetary cost of a single system;
(2) Multiply that cost times a selected ratio of Annual Energy Consumption Annual Gross Domestic Product (E/GDP Ratio) to estimate the input energy needed to get energy;
(3) Compare Estimated Output to Estimated Input; and
(4) Calculate the Expected Net Energy from constructing a large number of individual systems over time (Dynamic Net Energy Analysis.)
Among other things, the accuracy of the model
is limited by the inability of market price and associated GDP accounting
procedures to account for "externality problems" such as impact on and
services from environmental resources, distribution of income and wealth,
social justice (who benefits and who pays), monopoly effects, joint
Probably, the most counted‑on substitute for fossil fuels has been the generation of electricity from nuclear power (fission, breeder reactors, and fusion;) but there is uncertainty about ultimate costs, safety, the efficacy of the undertaking, the risk of serious environmental consequences, the cost of decommissioning of the systems, safe disposal of long‑term radioactive waste, the associated impact on global ecosystems. The likelihood of a catastrophic accident increases as large numbers of plants are operated. The availability of Uranium for fuel, alone, may be a limiting factor on the long‑term viability of nuclear power.12 The analyses in this paper do not attempt to account for any of these potential negative consequences.
Others are suggesting other alternative forms of energy such as wind, photovoltaic, hydrogen, biomass, ad infinitum, to help solve the dilemma of fossil‑fuel depletion. All candidates for substitution must be subjected to careful and comprehensive net‑energy scrutiny to insure that we do not pour energy "down a rat hole" and promise more than can be delivered.
Most net‑energy analyses of nuclear power only estimate the net‑energy available at the "bus‑bar" and do not include the energy cost of transmission and distribution and some did not include the energy cost of plant decommissioning and disposition of radioactive waste; and as previously stated, many only include the direct and latent consumption of energy in the construction and operation of the plants. Importantly, they did not consider the embodied‑energy consumption associated with labor, interest, dividends and tax costs. Further, it is important to understand that there is a massive up‑front energy investment in the plant construction and fuel acquisition, and the associated transmission and distribution systems. Several years pass after construction begins before a net‑energy profit is realized (if any.)
Using the Cost time E/GDP approach, an "optimistic" one‑plant analysis shows that one plant may yield about 3.8 times as much energy as is input to the system over a 40‑year period. However, under a continuous construction and decommissioning program the annual dynamic net‑energy yield is smaller.
Table 2 is an extracted image of the spreadsheet model. It shows an "optimistic" estimate of the "static" net‑energy yield from one 1000‑megawatt power plant over a 40‑year period. It includes total costs of construction of generating plant and transmission and distribution plant, acquisition of fuel and disposal of all residual wastes (fuel and plant) 40 years from start‑date of construction.
It is a snapshot of the 40‑year cycle.
Table 3 is extracted from the Dynamic Net‑Energy Spreadsheet Model and shows selected Years 1, 20, and year 100 results. It is assumed that one new plant is started each month for 100‑years. Table 3 uses Table 2 static net‑energy results (Column G) and distributes them over the lifecycle of the plant, as indicated in Column H , I and J of Table 3. A one‑plant‑per month program allows construction of 1200 new plants in 100 years Under "optimistic assumptions."
Cumulative Net‑Energy Output is negative for 20
Table 3 ‑ Dynamic Net‑Energy Analysis ‑ 1 Plant/Mo. (Optimistic)
Figure 4 shows estimated Annual Net Energy using the Optimistic assumptions of Table 2 and comes from the Dynamic Net Energy Model (extract in Table 3, above.)
Capacity Factor: Currently, Nuclear Plants currently report high capacity factors (actual compared to potential.) The reason for the high rates is that they are now being used for "base load" capacity ‑ in other words they are selectively being kept on line in preference to other plant types (coal, natural gas, etc.) If nuclear power systems were to become the primary source of energy (or occupy a much larger share) then they would suffer the vicissitudes of demand for electricity and the system would be susceptible to the timeof‑day, seasonal demand changes, cycling of the economy, etc. and the capacity factor would, necessarily, be much smaller. It was found in the original study' (when Total Net Generation is divided by Total Capability –Nameplate times 8760 hours/yr.) the "Efficiency Factor" was in the neighborhood of 50%. As nuclear plants were added to generating capacity from 1957 to 1983, the Efficiency Factor of the total system steadily dropped to a low of 40% in 1983. (This will be updated.)
Plant Cost: The base plant cost is for generating plant. Transmission and distribution plant cost is estimated to be 50% of generating‑plant cost. In the original study (Tyner dissertation) it was concluded that it was decided that it would be conservative to estimate Transmission & Distribution Lifecycle Cost at 45% of Generating‑Plant Cost. 50% is used at this time but this section needs additional scrutiny.
It is concluded that any expectation that Nuclear Power will be a viable substitute for fossil fuels is, at best, questionable. Such an undertaking appears to be nothing more than a roundabout way of consuming fossil fuels –at best, an investment in the storage of a small amount of fossil fuel in a relatively dangerous form. More plants increase the likelihood of a major catastrophic accident at some point in time. Even under the "optimistic" assumptions used in the models, the low and latent net‑energy yields appears to accelerate the depletion of the remaining fossil‑fuels stocks.
Unfortunately, a similar study of wind power showed similar results.13
It is suggested that the curious obtain a copy of the analytical model, available both in Lotus 1‑2‑3 and Excel Format, and plug in their own assumptions for any type of energy‑transformation system. It can be obtained at email@example.com for a $10 handling fee.
One can hardly overstate the importance of petroleum (domestic and imported) natural gas and coal to our current standard of living and all are contributing to the greenhouse gas problem. Nuclear proponents often claim that nuclear power has "negligible" air pollution and "zero" carbon emissions. (Electric companies also deceivingly advertise that electric vehicles are pollution free.) Even if we accept the argument that nuclear‑generated electricity use does not "directly" generate very much air pollution and carbon, large nuclear construction programs such as discussed in this paper, would "indirectly" increase air pollution and carbon emission because they would be largely constructed by burning more fossil fuels. One cannot maintain the current standard of living (let alone economic growth) and build hundreds of new nuclear plants without increasing the rate of fossil fuel use. The current set of nuclear plants must be retired soon. Any new plants that are built cannot provide new net energy, if any, for years down the line. Therefore, to argue that building nuclear plants will reduce greenhouse gases is specious.
There is the additional risk of catastrophic accident by having more operational plants. It will take a long time to acquire the human and institutional skills needed to operate large numbers of nuclear plants, safely. We have a lot experience with aircraft and automobile, refinery operation yet we still have major accidents –it happens. It is arrogant to presume that nuclear operations would escape the chance of catastrophic accident.
The opportunity for nuclear‑weapons proliferation increases. If CIA agents will sell out for a few bucks so will those in control of nuclear materials.
There are a number of approaches to net energy analysis, all subject to some limitation or another. For an extensive discussion of net energy approaches (except the current model,) see < http://www.oilanalytics.org/neten1.html > the website of Cutler Cleveland and Robert Kaufman. [MFS note: try < http://www.oilanalytics.org/index.html >.}
Static Net‑Energy explanatory comments:
Line 11 ─ Plant Cost Involves both Materials and Labor: The monetary accounting system is the only accounting system of record that accumulates fairly comprehensive historical costs of industrial and commercial processes. To the best of my knowledge the historical record of energy/materials expenditures for a particular end‑use item is practically non‑existent. Money expenditures reflect the summation of identifiable associated historical costs and are available as a surrogate from which to estimate the amount of energy embodied in an object.
For example, it is assumed that money paid for any material used in the construction of the plant covers all "to‑date" costs (hence an inferred relationship of monetary cost and embodied energy) that have been incurred up to the point of purchase. This may involve a set of processes far into the past of our industrial society.
Materials Example: For example, an amount of concrete used in constructing a plant involves energy and materials depletion. It involves, not only the mining, milling, transportation of all the components of concrete, but involves all the processes (and related energy expenditures) of the tools and equipment making up the set of "stuff' needed to mine, mill, fabricate the tools needed to make concretemanufacturing and transportation manufacturing and handling components. One can also imagine taking this process back several steps (years) in the industrial process. The accumulation of knowledge base to do all of this "stuff' also has an energy/materials/environmental‑resource cost.
The Cost of Energy to Obtain Labor: Labor, in this discussion is meant to include all human input to the process of providing nuclear power. It includes the payment to executives, engineers and scientists, construction workers, clerks, janitors, consultants, ad infinitum. The Table 2 example assumes that payments to Labor are at the prevailing salary/wage scales of our modern society. The money paid to labor is exchanged for energy‑embodied goods and services (housing, furniture and fixtures, utilities, food, clothing, automobiles, gasoline, ad infinitum.) None of these goods or services can be provided except by a corresponding depletion of energy, materials and environmental resources.
Line 12 ─ Transmission and Distribution (T&D) Costs: In an earlier study data showed that Plant cost and T&D costs were approximately the same. In this study it was assumed that T&D costs were 50% of Plant Cost. I have seen references to high‑KVA lines costing $550,000/mile ($1995).
Line 14: The term "fixed charge" involves electric‑utility finance matters and involves payments to principal, interest and dividends to bondholders and stockholders, and taxes. All of these money payments are identified as energy inputs in this analysis and are assigned to the operating electric utility, i.e., as a cost of getting the energy.
Lines 16 and 17 ─ Operation and Maintenance Costs: Both include expenditures for materials and labor. General plant O&M is assumed to be 7 mills per kilowatt hour and Other Plant at 1 mill per kilowatt hour.
Line 18, Fuel Cost: The fuel cost used in the current table is 8 mills per kilowatt hour. Recent DOE estimates are from 5 to 8 mills per kilowatt hour.
Line 19, Decommissioning and Waste Disposal: This is a highly unknown cost because, to the best of my knowledge, only small plants have been decommissioned and the long‑term waste problem is yet to be resolved. In this case, I have assumed that the cost of decommissioning and long‑term waste disposal costs are 25% of plant cost.
1. Gene Tyner, Sr., Ph.D.,
Economics/Interdisciplinary: Economics, Civil Engineering and Environmental
Science, Geography, Management and Philosophy. Author lives in Norman,
Oklahoma. [MFS note: Dr. Tyner died
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