Section VI – Assessing a Hypothetical All-Nuclear Energy Infrastructure for 2100
While currently the United States consumes around 18 billion BOE of gross thermal energy, in actuality, this energy is provided to the end consumer in two basic forms—dispatchable electricity and fuels used directly by the consumer for transportation, heating, industrial processing, etc. From 2007 data for the year prior to the start of the current recession, the distribution of gross thermal energy consumed as electricity and as fuels can be determined.
As shown in Fig. 14, in 2007, the United States consumed 17.482 billion BOE of gross thermal energy. That same year, 4.14 million GWh of electricity was generated. The EIA provides historical data on the thermal efficiency of the conversion of fossil fuels and nuclear energy into electricity, as well as the number of GWh generated by each. In 2007, the average thermal conversion efficiency was 1,724 BOE per GWh of electricity generated. Using this conversion, 7.154 billion BOE of gross thermal energy was used to generate that year’s 4.14 million GWh of electricity. The balance of 10.328 billion BOE was, thus, consumed as fuel by the end-consumer. That year, the split was 40.9% of the total BOE used for electricity and 59.1% for fuels. (The split each year, of course, varies somewhat due to weather, price, and other economic factors. In recent years, the split has been right around 40%/60%, so 2007 is a representative year.)
Recall that the projection for 2100 is 31.25 billion BOE of gross thermal energy needed. Compared to 2007, this represents a growth of about 79%.
31.25 billion BOE in 2100 ÷ 17.482 billion BOE in 2007 = 1.788
Applying this to the 2007 electricity consumed yields a projected need for 7.42 million GWh in 2100.
4.15 million GWh in 2007 x 1.788 = 7.42 million GWh in 2100
In 2100, the estimated need for end-consumer fuels is about 18.5 billion BOE.
10.328 billion BOE of fuels in 2007 x 1.788 = 18.47 billion BOE in 2100
The balance of about 12.8 billion BOE would be used to generate the needed electricity.
31.25 billion BOE needed in 2100 – 18.47 billion BOE of fuels in 2100
= 12.78 billion BOE used to generate electricity in 2100
These results are shown in Fig. 15.
A. If using only nuclear energy, the United States will need 6,500 1-GW plants operating by 2100
For this hypothetical assessment of an all-nuclear energy infrastructure, it is assumed that in 2100 the United States is powered only by nuclear fission power plants. The nuclear electricity generated is used to supply electrical power to the end-consumers and to produce hydrogen fuel to be used as fuel by the end-consumers. This is depicted in Fig. 16.
Using this model, how many 1-GW nuclear power plants would need to be operating in 2100 to provide:
- 42 million GWh of dispatched electricity.
- 47 billion BOE of hydrogen fuel compressed to 6,500 psi.
In this analysis, each of these nuclear power plants is assumed to generate 1 GW of power and to operate at full power for 95% of the year. Each of these 1-GW plants would be capable of delivering 8,322 GWh of energy a year.
1 GW x 24 hours/day x 365 days/yr. x 0.95 = 8,322 GWh per plant
In 2100, the projected electrical energy need for the United States is 7.42 million GWh. To produce this with 1-GW nuclear power plants would require 892 plants.
7.42 million GWh ÷ 8,322 GWh/plant = 892 1-GW plants
Obviously, conventional nuclear power plants do not produce hydrogen directly. As seen in Fig. 16, hydrogen is produced through electrolysis where nuclear electricity is used to split the H2O water molecule into its constituent hydrogen and oxygen atoms. The hydrogen is captured, compressed, and stored for end-consumer use as a fuel replacement for oil and natural gas.
The author estimates that—allowing for some technology improvement in the energy efficiency of the electrolyzers and compressors—producing and storing hydrogen for a lower heating value (LHV) use, such as home heating, will require 2,529 kWh of nuclear-electricity to produce one BOE of hydrogen fuel compressed to 6,500 psi. As seen in the following calculation, to produce 18.47 billion BOE of end-consumer hydrogen fuel used at LHV conditions, it requires 47 million GWh of electricity. This is ten times (10X) the amount of electricity consumed in the United States in 2006.
18.47 billion BOE of hydrogen fuel x 2,529 kWh/BOE of hydrogen @ 6,500 psi
÷ 1000 kW/MW ÷ 1000 MW/GW = 46,710,630 GWh for producing fuel
Recalling that each 1-GW plant will ideally yield 8,322 GWh per year, a total of 5,613 1-GW nuclear power plants would be required, in 2100, to provide U.S. consumers with needed end-consumer fuels.
46,710,630 GWh in 2100 ÷ 8,322 GWh/nuclear power plant/yr
= 5,613 1-GW plants needed in 2100 for fuel
By combining these two estimates for the number of 1-GW nuclear power plants required to produce both dispatched electricity and hydrogen fuel, an estimate of the total XX GW of generation capacity needed in 2100 to provide 31.25 billion BOE can be determined. To replace fossil fuels by 2100, the United States would need about 6,500 GW of continuous generating capacity—or 6,500 1-GW nuclear power plants!
892 for electricity + 5,613 for fuels = 6,505 1-GW plants in 2100
Currently, the United States has about 1,100 GW of generating capacity. Further, the United States only has 104 GW of nuclear power generating capacity. The fact that the United States will need in the ballpark of 6,500 GW of non-fossil fuel generating capacity by 2100 illustrates the magnitude of the challenge America has to overcome to become energy secure by 2100.
B. Expanded conventional nuclear fission is not a solution for 2100
The likely eventual non-fossil fuel energy source will be fusion nuclear energy. Developing this new type of nuclear energy has been underway for over half a century. While progress has been made in understanding the basic physics of non-explosive fusion energy, there is no current estimate for when commercialization of this technology will enable fusion plants to be built. Thus, with advanced nuclear fusion not being a current candidate for replacing fossil fuels, can conventional nuclear fission be used instead?
Fission nuclear energy, with sound plant siting and modern designs, offers a highly reliable and operationally safe baseload electrical power generation capacity. The challenges it faces, however, are not insignificant. These include physical security, damage containment in the event of extreme acts of nature (e.g., earthquakes) or terrorism, developing decades-long acceptable local waste storage at nuclear power plants, identifying acceptable millennia-long environmental radioactive waste disposal methods, denying uranium/plutonium production for weaponization by potentially hostile nations, and having sufficient fuel to power the plants for their expected 100+ year lives. Balancing these serious issues with the need to maintain a robust domestic nuclear power industry—anticipating the industry’s eventual transition to fusion nuclear energy—leads the author to conclude that the use of uranium fission nuclear power will remain modest in the United States this century. Current plants totaling only about 104 GW—many with designs dating from the 1970s—will likely be modernized or replaced. A modest expansion of the total generation capacity to about 150 GW may also be undertaken, depending on the size of U.S. reserves of uranium fuel. However, any broad expansion of conventional uranium fission is unlikely.