EP75: The Renewable Delusion: Why Transition Alone Won’t Power Tomorrow’s World

Summary:

In this episode, we examine "The Renewable Delusion: Why Transition Alone Won’t Power Tomorrow’s World," which argues against a full-scale transition to renewable energy sources, claiming that such a shift is impractical for meeting the needs of megacities and modern life. Instead, the author advocates for a diversified energy strategy that prioritizes nuclear energy as the primary source, with natural gas serving as a backup. The author supports their claims by analyzing key metrics such as energy density, power density, energy return on investment, and cold start times, concluding that nuclear energy is superior to renewables in terms of efficiency, reliability, and scalability.

Questions to consider as you read/listen:

1. What are the strengths and weaknesses of nuclear energy compared to other energy sources, particularly renewable energy sources, in meeting the energy demands of modern societies?
2. What are the key factors to consider when evaluating the practicality and sustainability of a large-scale energy transition away from fossil fuels, and what are the potential consequences of such a shift?
3. How does the concept of energy diversification, incorporating both non-renewable and renewable sources, differ from energy transition, and what are the advantages and disadvantages of each approach?

Long format:

 The Renewable Delusion: Why Transition Alone Won’t Power Tomorrow’s World

By Justin James McShane

October 30, 2024

TL;DR:

An effective energy policy should prioritize affordability, reliability, and minimal environmental impact. Key metrics like energy density, power density, EROI, and cold start times reveal that nuclear energy, due to its high density and efficiency, is the best option for meeting large-scale energy demands. Natural gas also offers flexibility and reliability, making it a viable backup when nuclear is not feasible. While renewables have their place, a total reliance or even majority reliance on them is impractical for sustaining megacities and modern life. A diversified approach—anchored in nuclear and natural gas, with renewable supplementation—best ensures a stable, sustainable energy future.

Introduction:

In a world increasingly focused on sustainable development and economic stability, determining the best path forward for energy policy demands a nuanced approach. Energy systems must be economically viable, environmentally sensitive, and capable of delivering reliable power on demand. The balancing act between these factors is challenging, particularly with growing calls for energy transition toward renewables. However, by analyzing key metrics such as energy density, power density, energy return on investment (EROI), capacity factor, and cold start times, we can begin to identify which energy sources best meet modern society's extensive demands. In examining these metrics, nuclear energy and natural gas emerge as essential components in creating an effective, diversified energy policy. This analysis delves into the attributes that make nuclear and natural gas energy sources crucial for supporting the continuous energy flow (base load) required for contemporary urban and industrial needs, while considering the limitations and benefits of renewable options like wind and solar. As we shall see an energy transition to entirely to renewables or even one where it is predominately renewables is not possible if we want to keep our mega cities and current lifestyle.

Information:

The goal of any energy system is to be affordable in order to drive economic development and improvements in quality of life, reliable so as to be available on demand in its various forms, most of all as uninterruptible electricity, and convenient to give consumers virtually effortless access to preferred household, industrial, and transport energies. Where environmental concerns sit in the weighing of the above is debatable but the above sentiments, I don’t think are reasonably debatable.

In environmental terms, power density is about claiming space: land use intensity (m2/W) is its obvious inverse. But there are other intensities to consider, above all the intensity of water use (g H2O/J) and carbon intensity (g C/J), a marker of the human interference in the global biogeochemical carbon cycle that quantifies the emissions of CO2, the dominant anthropogenic greenhouse gas. How that is balanced is beyond the scope of this treatment.

Importantly, we can to a degree reduce all of these goals stated above (but for the priority/value judgement involved with environmental issues) into 5 statistics as they are quantifiable: (1) energy density, (2) power density, (3) energy return on investment, (4) capacity factor and (5) cold start up times. Let’s look at each.

ENERGY DENSITIES

The heat value of a fuel is the amount of heat released during its combustion. Also referred to as energy or calorific value, heat value is a measure of a fuel's energy density and is expressed in energy (joules) per specified amount (e.g. kilograms). There are many reasons to prefer sources of high energy density, particularly in modern societies demanding large and incessant flows of fuels and electricity. Obviously, the higher the density of an energy resource, the lower are its transportation (as well as storage) costs, and this means that its production can take place farther away from the centers of demand.

 

Heat value/ Energy Density

Natural uranium, in FNR

28,000 GJ/kg

Uranium enriched to 3.5%, in LWR

3900 GJ/kg

Natural uranium, in LWR (normal reactor)

500 GJ/kg

Natural uranium, in LWR with U & Pu recycle

650 GJ/kg

Hydrogen (H2) (in theory, no prototype)

120-142 MJ/kg

Methane (CH4)

50-55 MJ/kg

Liquefied petroleum gas (LPG)

46-51 MJ/kg

Petrol/gasoline

44-46 MJ/kg

Diesel fuel

42-46 MJ/kg

Crude oil

42-47 MJ/kg

Natural gas

42-55 MJ/kg

PV panel

39.5 MJ/lg

Dimethyl ether - DME (CH3OCH3)

29 MJ/kg

Hard black coal (Australia & Canada)

c. 25 MJ/kg

Hard black coal (IEA definition)

>23.9 MJ/kg

Methanol (CH3OH)

22.7 MJ/kg

Wind turbine

21.48 MJ/kg

Sub-bituminous coal (Australia & Canada)

c. 18 MJ/kg

Sub-bituminous coal (IEA definition)

17.4-23.9 MJ/kg

Lignite/brown coal (IEA definition)

<17.4 MJ/kg

Firewood (dry)

16 MJ/kg

Lignite/brown coal (Australia, electricity)

c. 10 MJ/kg

Geothermal (heat capacity of water)

4.186 MJ/kg

*Uranium figures are based on 45,000 MWd/t burn-up of 3.5% enriched U in LWR

• MJ = 106 Joule, GJ = 109 J
• MJ to kWh @ 33% efficiency: x 0.0926
• One tonne of oil equivalent (toe) is equal to 41.868 GJ

 

POWER DENSITIES

Power is simply energy flow per unit of time (in scientific units, joules per second, which equals watts, or J/s = W), spatial density is the quotient of a variable and area, and hence power density is W/m2, that is, joules per second per square meter. The power density rates include not just the physical power plants land footprint but also all right of way (ROWs) considerations including aspects such as transmission lines, access ways, set backs and substations. Perhaps the most important attribute of an energy source is its density: its ability to deliver substantial power relative to its weight or physical dimensions. When choosing a power source, you want a higher power density so that in the smallest space possible, we can produce the most energy so that land can be otherwise used for agriculture, industrial use, residential use, commercial use or even leisure use as opposed for power generation.

For renewables, the research provides these values.

For non-renewables, the research reveals the following.

In other words, we can compute that one nuclear power plant produces the energy of thousands of wind turbines easily. To generate the same amount of energy as a typical nuclear reactor, it would take several hundred wind turbines depending on the size of the reactor and the wind turbine, with estimates often ranging between 500 and 1,000 or more turbines to match the output of a single nuclear reactor. A nuclear power plant has several reactors typically. This just gets us to equivalent power rates referring to Watts. When we add in the spatial component (m2), we can very plainly see that “energy transition” is problematic. For example, wind turbines must be set apart to avoid excessive wake interference. Turbines must be placed at least three, and better five, turbine diameters apart in the crosswind direction, and at least six and preferably ten diameters in the downwind direction. You can do the math, 1000s of turbines separated that much by regulation versus the typical footprint of a nuclear power plant doesn’t compare.

Just to further put a point on the issue of total energy transition away from fossil fuels towards lower density intermittent renewables, Professor Smil is instructive and is worth directly quoting:

Tomorrow's societies, which will inherit today's housing, commercial, industrial, and transportation infrastructures, will need at least two or three orders of magnitude more space to secure the same flux of useful energy if they are to rely on a mixture of biofuels and water, wind, and solar electricity than they would need with the existing arrangements. This is primarily due to the fact that conversions of renewable energies harness recurrent natural energy flows with low power densities, while the production of fossil fuels, which depletes finite resources whose genesis goes back 106–108 years, proceeds with relatively high power densities… Fossil fuels (when transportation and transmission ROW needs are included) generally supply energy with power densities higher than those prevailing in city downtowns, and the only instances in which the power densities of energy use surpass those of common ways of energy production are the energy-intensive industrial processes (often well above 1,000 W/m2) and city blocks consisting of densely packed high-rise buildings (on an annual basis they can go well above 500 W/m2) and during short periods of peak demand (driven by winter heating or summer air conditioning) in downtown cores, where they can go to as much 1,000 W/m2 or even more… Net fossil fuel imports added about 750 GW to the domestic production, and so the power density of the entire system would be about 50 W/m2. As expected, the overall power density of the nascent energy supply delivered by new conversions of renewable energy sources is much lower: the growing triad of wind turbine–generated electricity, solar electricity, and liquid biofuels reached a bit over 60 GW in 2010, and even after counting only the land actually occupied by wind turbines and their infrastructure and excluding all transmission ROWs the new renewable system delivers with an overall power density of just 0.4 W/m2, less than 1/100th of the currently dominant arrangements… If all of America's gasoline demand in 2012 (a total of 16.96 EJ, or 537.87 GW) were to be supplied by corn-based ethanol produced with that power density, then the United States would have to be growing corn for ethanol on 234 Mha, an area nearly 75% larger than that of all recently cultivated land and a third larger than the country's total cropland… [In conclusion], such a ramping-up of all kinds of capacities [that come with a total transition from fossil based fuels to strictly renewables]—design, permitting, financing, engineering, construction, all going up between one and five orders of magnitude in less than two decades—is far, far beyond anything that has been witnessed in more than a century of developing modern energy systems. And that still leaves out two other key facts, namely, that such a gargantuan renewable energy system would need an enormous expansion of high-voltage transmission and would require the creation of an entirely new, hydrogen-based society….To totally de-carbonize Britian in favor of renewables would require 240,000 km2 which is essentially the entire area of Britain. The same holds true for Germany as it would require about 350,000 m2 which is likewise essentially the country’s entire area. And there is Japan, which to decarbonize would require nearly 600,000 km2 of land which is nearly 60% more than the area of the four main islands.  [Finally,] a reality check is in order: how can this prospect be squared with the growth of megacities whose densely crowded, high-rise blocks may average throughout the year more than 500 W/m2 and reach 1,000 W/m2 during the hours of peak demand? Since 2007 more than half of the world's population has been living in cities. By 2050 that share will be above 70%, and more than half will live in megacities with populations of more than 10 million, areas with the highest power density of final energy uses. Even if the power densities of energy use in many megacities were to decline gradually in the decades ahead, it would be impossible to supply them with decentralized PV-based electricity…. New energy arrangements are both inevitable and desirable, but without any doubt, if they are to be based on large-scale conversions of renewable energy sources, then the societies dominated by megacities and concentrated industrial production will require a profound spatial restructuring of the existing energy system, a process with many major environmental and socioeconomic consequences.

(Power Density: A Key to Understanding Energy Sources and Uses (MIT Press) by Vaclav Smil

ENERGY RETURN ON INVESTMENT

Energy Return on Investment (EROI) is a ratio that measures the amount of usable energy produced from an energy source compared to the amount of energy used to create it. An EROI of less than or equal to one means the energy source is a net "energy sink" and can no longer be used as an energy source. An EROI of about 7 is considered break-even economically for developed countries, providing enough surplus energy output to sustain a complex socioeconomic system and cities.

Life-cycle energy ratios for various technologies

 

 

Source

R3 energy ratio – EROI

(output/input)

Hydro

 

Uchiyama 1996

50

 

 

Held et al 1977

43

 

NZ run of river

Weissbach 2013

50

 

Quebec

Gagnon et al 2002

205

Nuclear (centrifuge enrichment)

 

See Table 1

81

 

PWR/BWR

Kivisto 2000

59

 

PWR

Weissbach 2013

75

 

PWR

Inst. Policy Science 1977*

46

 

BWR

Inst. Policy Science 1977*

43

 

BWR

Uchiyama et al 1991*

47

Coal

 

Kivisto 2000

29

 

black, underground

Weissbach 2013

29

 

brown,open pit, US

Weissbach 2013

31

 

 

Uchiyama 1996

17

 

 

Uchiyama et al 1991*

16.8

 

unscrubbed

Gagnon et al 2002

7

 

 

Kivisto 2000

34

Natural gas

- piped

Kivisto 2000

26

 

- CCGT

Weissbach 2013

28

 

- piped 2000 km

Gagnon et al 2002

5

 

LNG

Uchiyama et al 1991*

5.6

 

LNG (57% capacity factor)

Uchiyama 1996

6

Solar

 

Held et al 1997

10.6

Solar thermal parabolic

 

Weissbach 2013

9.6

Solar PV

rooftop

Alsema 2003

12-10

 

polycrystalline Si

Weissbach 2013

3.8

 

amorphous Si

Weissbach 2013

2.1

 

ground

Alsema 2003

7.5

 

amorphous silicon

Kivisto 2000

3.7

Wind

 

Resource Research Inst.1983*

12

 

 

Uchiyama 1996

6

 

Enercon E-66

Weissbach 2013

16

 

 

Kivisto 2000

34

 

 

Gagnon et al 2002

80

 

 

Aust Wind Energy Assn 2004

50

 

 

Nalukowe et al 2006

20.24

 

 

Vestas 2006

35.3

Geothermal

Traditional

 

9

 

Enhanced Geothermal Systems (EGS)

 

unknown

CAPACITY FACTOR

Capacity factors allow us to examine the reliability of various power plants. It basically measures how often a plant is running at maximum power. A plant with a capacity factor of 100% means it is capable and does produce power all the time at full load. Nuclear has the highest capacity factor of any other energy source—producing reliable, carbon-free power more than 92% of the time. That’s nearly twice as reliable as a coal (49.3%) or natural gas (54.4%) plant and almost 3 times more often than wind (34.6%) and solar (24.6%) plants.

 

Capacity Factor

Nuclear

92.7%

Geothermal

71%

Natural Gas

54.4%

Coal

49.3%

Hydropower

37.1%

Wind

34.6%

PV

24.6%

 

 

 

 

COLD START TIME

Cold start time is the time from full shut down for greater than 24 hours to full achieving full load. We want fast cold state up time to meet our goal which is to make sure that we have energy when there is a demand for it.

Hydrogen

30 seconds to a few minutes in theory

Natural gas

several minutes to 6 hours

Wind

10 minutes

Solar

10 minutes

Hydroelectric:

10 minutes

Geothermal

2-4 hours

Coal

6-48 hours

Nuclear

12 hours

 

ENVIORNMENTAL IMPACT:

And as a bonus for those interested in the numbers when it comes to environmental impact, I have provided both water related statistics and issues as well as gCO2/kWh and “green house gas” emission rates for consideration.

gCO2/kWh

Japan

Sweden

Finland

coal

975

980

894

gas thermal

608

1170 (peak-load, reserve)

-

gas combined cycle

519

450

472

solar photovoltaic

53

50

95

wind

29

5.5

14

nuclear

22

6

10 - 26

hydro

11

3

-

 

 

CONCLUSION

 

In conclusion, determining an optimal energy policy requires balancing multiple priorities such as affordability, reliability, and convenience. Through key metrics like energy density, power density, energy return on investment (EROI), and cold start times, we can assess various energy sources in a way that readily reveals the strengths of nuclear energy over others. Nuclear power, with its high energy density and superior EROI, stands out as the most efficient and practical solution for meeting large-scale energy demands. One nuclear reactor can generate the same amount of energy as hundreds, if not thousands, of wind turbines, all while requiring far less land and infrastructure. The power density of nuclear energy also allows for continuous, uninterruptible electricity generation, a critical requirement for industrial and societal stability that intermittents like wind and solar cannot.

While natural gas offers a lower EROI and less energy density than nuclear, it still surpasses most renewable sources in terms of efficiency and reliability. Natural gas, with its shorter cold start times and more manageable infrastructure, represents a viable alternative when nuclear energy is not practical over the other alternatives.

By the numbers, nuclear energy should be the primary focus for long-term energy solutions, with natural gas as a secondary option. This approach ensures that energy policy remains centered on practical, scalable solutions that support economic growth and uninterrupted energy supply, providing the best outcomes for modern society’s demands. In the end, the logical outcome is energy diversity instead of energy transition away from fossil fuels or nuclear if we want to keep our mega cities and current quality of life and rates of growth.

“Energy transition" refers to a large-scale shift in an entire energy system, typically moving away from fossil fuels and towards renewable energy sources to combat climate change, while "energy diversification" means actively increasing the variety of energy sources used within a system, which can include incorporating renewables but also means relying on multiple sources to reduce dependence on any single one, enhancing energy security; essentially, diversification is a tactic within a broader energy transition strategy.

While adding intermittents is politically appealing a goal of shifting the entire energy system to that exclusively is not wise and is not something that can be done if we want to keep our mega cities and current quality of life and rates of growth. Basing our energy sector on non-renewables primarily nuclear and natural gas and supplementing that with occasional intermittents is a sound path forward that is supported by the data.

 

Conclusion:

The data-driven approach to energy policy reveals a clear path: a balanced system grounded in nuclear and natural gas, supplemented by renewable energy where feasible. Nuclear energy, with its unmatched energy density and EROI, proves indispensable for sustaining large populations and high-demand areas. Natural gas provides flexibility with quicker cold start times, making it a practical complement to nuclear. Although the allure of a complete shift to renewables is strong, the demands of megacities and modern life require energy diversity rather than a singular transition or even one that is dominated by renewables. Moving forward, embracing a diversified energy portfolio allows for stability, economic growth, and resilience against the constraints of any single energy source. To secure an efficient, reliable energy future, we must prioritize solutions grounded in practicality and scalability, ensuring that energy policy serves both current needs and long-term sustainability.

 

Sources:

Power Density: A Key to Understanding Energy Sources and Uses (MIT Press) by Vaclav Smil

https://world-nuclear.org/information-library/facts-and-figures/heat-values-of-various-fuels

https://corporatefinanceinstitute.com/resources/accounting/energy-return-on-investment-eroi/#:~:text=Energy%20return%20on%20investment%20(EROI)%20is%20a%20ratio%20that%20measures,gained%20from%20selling%20said%20energy

https://www.investopedia.com/terms/e/energy-return-on-investment.asp

https://www.sciencedirect.com/science/article/abs/pii/S0360544213000492

https://www.sciencedirect.com/science/article/pii/S0301421518305512#:~:text=3.1.&text=Geothermal%20energy%20systems%20vary%20from,We/m2)

https://www.energy.gov/ne/articles/what-generation-capacity