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*
October 2002

Overview
    Table 1 - Net Energy for U.S. Economy
    Figure 1 ‑ Btu's to produce 1$ GDP
A Critique of Standard Economic Reasoning
Historical Energy Consumption Information
    Figure 2 ‑ U.S. Energy Disposition
    Figure 3 - Energy Flow Diagram
The Cost x (E/GDP) Model
Net Energy from Nuclear Power
One Plant Per Month Construction Program
    Optimistic
        Table 2 ‑ Static Net‑Energy Analysis
        Table 3 ‑ Dynamic Net‑Energy Analysis
        Figure 4 ‑ Annual Net Energy from 1200 Plants
        Figure 5 ‑ Cumulative Net Energy 1200 Plants
        Table 4 ‑ Summary of Cost x E/GDP Analyses 100 yr. Scenarios
        Table 5 ‑ Variables Changed for Results in Table 4
The Mississippi River Parable
    Table 6 ‑ Zero Net Energy Prices ‑ Selected Energy Types ‑ Delivered to End User
Conclusions
Closing Arguments
    The Environment
    Catastrophic Risk
    Weapons Proliferation
    Philosophical Conjecture
Appendix
References

Overview

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.

Table 1 - Net Energy for U.S. Economy

Most net‑energy studies only count as Input Energy, the "direct" fuels closely associated with the latent processes of construction and operation of an energy‑transformation systems and ignore the energy embodied in all of the in all the processes leading up to the construction, operation and delivery of energy to final users. Those procedures are sort of analogous to marginal cost analyses in economics. Consequently, many studies of nuclear power show high output/input ratios. ³ A reason for exclusion may be the lack of data to know what all was involved in the historic processes. Attempts to do this have been classified as Net­Energy Process Analyses.

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

Figure 1 ‑ Btu's to Produce 1$ GDP ($1996)

(Click image to enlarge.)

A Critique of Standard Economic Reasoning

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

Historical Energy Consumption Information

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 is a duplicate of the Department of Energy Energy Information Agency Diagram on the production and consumption of Electricity for Year 1999. Figures are Quadrillion Btu's of Energy (Q). It should be noted that it takes about 3 Btu's of Fossil Fuel to provide 1 Btu in the form of electricity.¹¹

Figure 3 -Energy Flow Diagram

Fig. 3, above, shows that 33.32 Quads of heat energy is consumed to provide 11.14 Quads (in Btu's) of Electricity to end users. It is recognized that electricity is a "high‑quality" energy form, with unique qualities for lighting, operating motors, communications systems, computers, i.e., for electricity‑specific applications. However, it should be recognized that when a kilowatt‑hour of electricity is needed for heat (for example, space heating) only 3413 Btu's of heat is available from each kilowatt hour of electricity, i.e., quality may be less material. Petroleum, for example, is superior in quality to electricity for powering our current transportation systems (aircraft, automobiles, locomotives, shipping, etc.) It will take some doing to have an all‑electric transportation system.

The Cost x (E/GDP) Model

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 production, etc. The model also involves substantial averaging of data, necessarily, and is thereby a broad (but inclusive) method. It is argued that most other net‑energy methodologies (except Howard Odum's eMergy procedure) exclude energy costs that are essential to understanding the viability of any proposed substitute for fossil fuels.