Energy and Society: Toward a Sustainable Future

Abstract

Energy is the single greatest lever that moves civilization. As a society, we have pulled upon fossil fuels as a historical source of energy, but have begun transitioning toward alternatives. This chapter explores our global move toward alternative forms of energy, their feasibility and impacts, and the kind of world we can create with a decarbonized and electrified future. We thus need to consider how much energy we need, and evaluate alternative sources of energy including nuclear power. Then we need to consider what the effects of achieving a sustainable energy future would be, including impacts on biodiversity and land use. These goals will aid in creating a sustainable civilization while mitigating the destruction of biodiversity and further impacts to planetary life support systems.

1 Introduction

Collaboration, tool making, tool use, and even trading have all now been identified in non-human animals. Our species is less special than we think. One unique thing we might still lay claim to is the use of novel ways to harness larger energy sources that magnify our strength and give us superpowers. Pelicans and albatross use the winds to soar, dolphins the power of the wave to surf, plants the power of the sun to grow, and all creatures are ultimately powered by solar energy. Humans, however, appear to be unique in harnessing and controlling these energy sources at a planetary scale, adding buried fossil fuels and even nuclear power to the mix.

Our superpower began with learning to tame fire, where we could harness energy beyond our metabolism to improve our chances of survival. This enabled us to derive more calories from food, to develop culture, and to extend our daylight hours to become a species that transcends ideas of the diurnal or nocturnal. We tamed the cold and the night. Fire and tools led to machines that helped us with agriculture, construction, entertainment, and war. For the machines to be more powerful, they needed to harness more than human energy, so we gave them the labor of other species—the ox, the donkey, the horse—and then the power of wind, water, eventually fire and steam, and then combustion engines.

It appears we have always learned how to exploit resources before we understood their consequences and how to manage them wisely. Fire gave us deforestation. Fossil fuels gave us water pollution, air pollution, damage to ecosystems, and perhaps most existential of all, climate change. Our division of the world by roads for our vehicles has disrupted ecosystems globally and fragmented the habitats of wildlife. In the contiguous United States, you are never more than 22 miles from a road, a long day’s walk. Many of our wild places feel like zoos—crisscrossed by four-wheel-drives—only the perimeter fences are farther off.

Our flirtation with atomic energy thrust upon us multi-generational waste management problems, and the proliferation of dangerous materials problems. It also has increased the risks of another existential challenge—nuclear war—or even just the more mundane terror of nuclear plant meltdown. As yet we have made no real effort to suggest that our capacity to harness much larger sums of energy than we use is anything but selfish, purely for our benefit.

Our pets may have benefited from warmer places to sleep but our livestock are more enslaved than ever, and might be considered part of our large industrial machine. One of the key units with which we talk about energy and power refers to our casual subjugation of another species—horsepower. Perhaps we can hope that our capacity to harness energy in excess of our personal needs means that we could harness some of the energy in cleaning up the problems we have created but surely this will only be arrived at if we recognize our interdependence on the health of all of the other species. You can imagine that we might dedicate 10% of energy production to righting environmental wrongs—a tithe for the earth perhaps—by cleaning waterways, filtering microplastics, restoring forests, and stabilizing our climate, but we haven’t risen to that level of interspecies collegiality yet. The waste heat and waste emissions of our energy systems are all that we give to ecosystems so far, a long shot from using a relevant amount of our energies to rejuvenate them and support the other species that indirectly support us.

With the irrefutable evidence of climate change caused by our consumption of fossil fuels, we are for the first time grappling with the consequences of the scale at which humanity now operates. It is indeed the Anthropocene. Our species and our stuff will be the dominating layer in the geological record of our age. Relatedly, we are now understanding our impacts on biodiversity and the risks that collapsing biodiversity poses for our species. At some scale of awareness much larger than academia or even environmentalism, we recognize that the ways we find, transform, move, process, and use energy will not enable our species, let alone other species, to thrive beyond this century. We need to reckon with how to provide the energy that defines a good life, at what consequences, and in so considering the effects on other species for the first time we must consider what a balance might look like.

Or otherwise stated: how will we live and how will we power those lives in a manner that leaves room for biodiversity to thrive, such that we might thrive long enough to find out not only what our species can achieve, but what interspecific equality and generosity might bring?

This returns us to speciesism and our self-interest. This contemporary framing forces us to confront the essential question of balancing our energy use desires (which are far beyond our needs) with our need for a healthy planetary system.

To discuss the future of energy is to discuss balance, and to face a host of uncomfortable questions about limits. This conversation about limits is old, back to Malthus and beyond. It was very much part of the environmentalist conversation of the 1970s, in the shadow of Silent Spring (Rachel Carson), The Population Bomb (Paul Ehrlich), and Limits to Growth (Club of Rome). John Holdren captured it with the brevity of a physicist in, Energy; a Sierra Club Battlebook.

In a hypothetical world, free of the constraints of biology and thermodynamics, such thorny, socioeconomic questions might not have to be asked at all; the energy problem would be reduced to the technical details of meeting any demand that happened to materialize. Unfortunately, we do not live in such a world. Energy is not merely the prime mover of technology; it is also a central ingredient in man’s impact on his environment. No means of supplying energy is without its liabilities, and no form of its consumption is without consequence to the ecosystems that support us.

Holdren, speaking of the 1970s energy crisis, goes on to say,

… it serves to suggest that there are no easy solutions to the so-called “energy crisis.”

And that was before we understood what climate change had in store for us.

2 History

We should probably start with what we know, or what we think we know.

Many treatises on energy and humans start with graphs (e.g., Fig. 9.1) of how our fuel use has evolved over the last few hundred years and show how we went from biomass to biomass-plus-hydro, to bio-plus-hydro-plus-coal, etc., with an ever-rising “exponential” increase in the energy use of humans. It is this ever-increasing demand for energy that concerns experts about how to balance our energy needs with constraints such as climate change, air quality, and the habitat of other organisms. The first fuel to amplify our impact was biomass—trees, something we have been using at a planetary scale for thousands of years.

Fig. 9.1

200-year history of global primary energy consumption

We are now aware that much of the denuding of the Mediterranean was to build the infrastructure to run the hot baths of Rome; the cedar tree that adorns the Lebanese flag required protective conservation efforts running as far back as the Roman Emperor Hadrian. There is little if any wild forest left in Western Europe because of our energy use patterns, agriculture, and war. 95% of American forests have been lost.¹ Half of the world’s biomass, mostly forest, equivalent to more than 1 trillion tons, is already lost (Elhacham et al. 2020).

Then in the nineteenth century, we found deposits of old biomass and learned to exploit them, too. First came coal, with the accompanying and enabling invention, the steam engine. This use steadily increased through 1900, when we first started using oil at scale. “Town gas,” known nowadays as natural gas, followed close on the heels of oil in ramping up through the twentieth century. By the middle of the twentieth century, fossil fuels were dominant, and our awareness of the problems they would present in terms of both air pollution and climate change were clear enough that by 1965 they made it to the U.S. President’s desk (Restoring the Quality of our Environment 1965).

This happened just as excitement around the peaceful uses of atomic energy was heating up, and many people imagined and advocated for huge quantities of nuclear power, some famously calling it “too cheap to meter.” In Understanding the “National Energy Dilemma,” (Understanding the national energy dilemma 1973) a document prepared for the Joint Committee on Atomic Energy, it was projected we would be using more than 100 Quads of non-fossil (implied nuclear) energy in the U.S. by 2050. This is more energy than the whole country uses today. Similar enthusiasms for enormous quantities of nuclear energy were not confined to the United States. Concerns over radioactive waste management and high-profile reactor accidents like that at Three Mile Island in 1979 tempered the general enthusiasm, and nuclear power has not grown at anything like the rate we once thought it would.

Hydroelectric power, a descendant of our early water wheels, also ramped up considerably during the latter half of the twentieth century as our capacity to build giant infrastructure projects and the ability to structurally engineer enormous concrete dams developed. Hydroelectric power is still our largest renewable energy contributor, though the best hydroelectric sites have mostly been exploited already, and new hydroelectric resources generally conflict with other environmental concerns including ecosystem destruction, population displacement, and water management.

Out of the multiple energy crises of the 1970s came a renewed interest in renewables, notably wind and solar, but also geothermal, wave, tidal, and biofuels. After three decades of being expensive niche energy sources, wind and solar started to compete economically at the turn of the twenty-first century, and only two decades later are often the lowest-cost energy option for new power plants. The advantage of fossil fuels is too great, the advocates say, their energy density (how much bang they give us per pound or kilogram) and their inherent property of being convenient storage mechanisms will mean we can never replace them. In the opposing camp, a century of steady developments in batteries has bridged this gap, and we can now imagine huge quantities of batteries storing yesterday’s sunlight for tomorrow’s trip to the grocery store and last week’s wind energy for next week’s home heating.

We haven’t stopped burning our original fuel (trees and biofuels), and in fact, we are using as much as ever. In the developing world, it is still used as firewood and heating fuels, with associated health and air quality problems. Comparatively, in the developed world, we now dedicate crops and residues from the paper and pulp industry as significant contributors to our energy systems. This creates tensions among land use, soil quality, and energy. These tensions might be further complicated by proposals to create “negative emissions” by using biofuels to create energy while CO₂ emissions are captured and buried deep underground. This Bio Energy and Carbon Capture and Storage (BECCS) is one of many negative emissions technologies that we now rely upon if we wish to stabilize the climate at or below 1.5 °C² by the end of the twenty-first century. The quantity that we must bury in these low-emission scenarios is at the very limit of what informed people consider possible.³ Indeed, we are forewarned that at the scale of 10 gigatons or 10 billion tons per year, the land use requirements will interfere with our other wants and needs including agriculture and forests. For perspective, we pull about 10 gigatons of fossil fuels out of the ground each year—more than a ton per person—and to imagine we will build an industry as large as the existing fossil fuel industry to pump its waste back into the ground may be the most tragic symbol of our hubris.

For perspective, as shown in Fig. 9.2, around 20% of all things that humans “move” each year are fossil fuels extracted from the ground. Once we bring those fossil fuels to the surface, we oxidize them. Since that means adding two oxygen atoms to each carbon atom, we increase the weight of carbon dioxide to be approximately half of all things we move each year. CO₂ is our single most prolific byproduct, all exhausted into the thin layer of atmosphere that we share with the rest of biodiversity on this precious rock floating through space.

Fig. 9.2

Annual global material flow estimates, in millions of tons per year (by the author)

Projections of historical energy-use numbers have been a common theme in treatises that complicate the future of energy. Such projections included factors or ratios that attempt to find the right multiplier for our population per capita energy use to project how much energy we need, but they all over-predicted our future energy use by orders of magnitude. This happened for many reasons; to name a few: over-estimating population growth, over-estimating the growth of energy consumption per capita, under-estimating the technological gains of efficiency, and nuclear techno-optimism.

3 On Fossil Fueling Our Species

Vast amounts of human labor, economic activity, and land are dedicated to finding, mining, refining, transporting, supplying, and consuming energy. Yet these inputs are hidden from us as the conveniences of modern life masque the dirty reality of those fuels. As you stand next to a car as it is filled with petroleum, you are probably not cognizant that you are pouring a volume of liquid as large as yourself into that vehicle, only to promptly burn it. Very few people are aware that a considerable proportion of rail freight is moving coal from mines to power plants—processes and machines that are nearly invisible to most of us. We just experience the convenience of electricity at the end of the plug. Fossil fuels are nearly a quarter of all materials humans move every year, including dirt and soil; though this jumps to half if we consider the CO₂ that results from burning those fuels. We move more CO₂ every year than we do every other physical material that our society is built from. No wonder the atmosphere is full of it. The average American in 2020 used directly and indirectly about 6000 kg or 6 tons of fossil fuels. If our daily allowance of fossil fuels were something we had to leave the house with, then our backpacks would weigh close to 40 lbs. What is amazing is how well we have hidden these flows of materials from ourselves. With ignorance, we don’t even need denial.

For illustration, America consumes around 20% of the world’s energy. The footprint of the supply chain is breathtaking: 700 million tons of coal is mined from 669 coal mines which feed tens of thousands of coal cars that are pulled from their mines to 241 power plants by thousands of diesel locomotives over 140,000 miles of freight rail track.

27 trillion cubic feet of natural gas is pulled from a few hundred offshore drilling rigs and close to a million terrestrial gas wells. The gas is moved through 321,000 miles of natural gas transmission lines, an effort that requires close to 1% of U.S. energy flow. Some of it is moved through 121 Liquid Natural Gas terminals and stored for later use in 400 underground caverns that are geological formations suitable to the task. They mostly don’t leak. Much of that gas is burned in 2000 gas-fired electricity generation plants, but much of it is further pumped through 1.32 million miles of gas distribution lines to connect to 69 million homes and 3 million commercial buildings that use gas for water heat, space heat, cooking, and other activities.

300 billion gallons of oil are drilled from close to a million wells, pumped by derricks, and delivered through 224,000 miles of pipeline and around a hundred oil tankers to 135 oil refineries that convert it to gasoline and diesel that is trucked by 100,000 tanker trucks to 150,000 gas stations to feed 265 million cars, trucks, and motorcycles.

And that is just in America. Early into the twenty-first century, we passed the mark of 1 billion cars in operation on the planet. Some people project we’ll get to 2 billion by mid-century.

One reason given by the fossil fuel industry to convince us not to switch to renewable energy is that the solar panels and wind farms will take up too much space, yet they do not count the incredible footprint of fossil fuel supply chains. If we covered a similar area to all of the land consumed by fossil fuel pipelines and coal-carrying railroad tracks, we would supply a similar amount of energy to the fossil fuel industry. In both cases, it is a few percent of the total land surface.

When thinking about our energy use, past or future, one cannot avoid thinking about its intersection with land use and material use, and its environmental effects on biodiversity. In looking to the future of energy for our species, we must inevitably confront these trade-offs.

4 Energy System Trade-Offs

We are already aware of the environmental trade-offs of fossil fuels. Coal mining has led to mountaintop removal and subsidence around mine sites. Enormous amounts of coal dust are liberated on every coal-train’s trip from mine-site to power-plant. Heavy and sometimes radioactive metals surround the countryside down-wind of coal plants. Oil slicks are common to leaking pipelines and to oil-tankers such as the Exxon Valdez. Accidents such as the Deepwater Horizon drilling accident and the burning oil wells of Iraq and Kuwait fill our minds with what can go wrong.

Coal replaced sail (wind power), not so much because it was cheaper, nor because it was faster, but because it was more predictable, and the emerging industrial economy wanted predictability. The coal ships were not so much faster than the sailing schooners that prevailed at the time, but they needed less skilled labor and were easier to schedule. In this anecdote we can see the trade-offs in time and human labor embedded in the way fossil fuels changed the way we do things. The speed of freight transport has only increased marginally from 10 to 15 knots in the last century, and we could choose to slow things down again to 10–12 knots, which would allow for (largely autonomous) solar-and wind powered freight. However, it appears that people are hell bent on the higher speeds that a heavier density fuel allows, thus pushing hydrogen and ammonia as potential shipping fuels.

At the turn of the century, we fretted about dwindling supplies of natural fertilizer—guano—and the devastating impact it would have on our agriculture and growth. The Haber–Bosch process and synthetic nitrogenous fertilizers were the result. This process, critical to modern agriculture and productivity, uses 1% of the world’s energy supply and produces 1.4% of CO₂ emissions. 7% of our greenhouse gas emissions are nitrous oxide, N₂O, the majority from these same fertilizers. These fertilizers cause algal blooms and vexing environmental problems, including the monoculture industrial agriculture that resulted, but the alternatives require more labor and would increase the cost of food which is seen as an intolerable compromise by many.

Nearly 10% of the world’s energy is now used in the service of finding, mining, refining, and transporting our fossil fuels and other energy sources. This number, sometimes known as Energy Returned on Energy Invested (EROI), gets higher each year as the fossil resources get harder to reach and lower in energy content.

This is not to say that solar and wind won’t also have trade-offs. Industrial solar farms amount to a cropping monoculture even worse than industrial agriculture in their effects on local biodiversity. Wind farms interfere with birds and insects. Hydroelectricity can destroy the ecosystems in the catchment area and dam basin. Advocates for the market sorting out these compromises are many, but mechanisms (e.g., a carbon tax) that “price in the environmental externalities” remain more theory than practice. We still don’t have terribly effective mechanisms for the exchange rates between dollars and degrees of climate change, let alone dollars vs. toxins vs. biodiversity destruction vs. climate vs. human flourishing. This is the extremely difficult moral calculus that vexes such proposals.

5 Predicting the Future

When we first started collecting energy data in response to the 1970s oil crises, there were many projections into the future of what demand would be, and these turned out to be far higher than we have actually seen. In a report commissioned by the Joint Committee on Atomic Energy, the Senate committee then tasked with understanding U.S. energy needs and futures—“Understanding the National Energy Dilemma” (Bridges 1973)—used forecasts into the future that would have had the U.S. using 100 quads by 1985, 160 quads by 2000, and more than 200 quads by 2050 in the “minimum” case. Such was the promise at the time of nuclear energy and the limitations of modeling using simple exponents. In 2019, the U.S. used 101 quads, and in 2020 used 92.

“Understanding the National Energy Dilemma” (Bridges 1973) might be seen as the techno-optimist viewpoint of the future; the Club of Rome’s more sanguine “The Limits to Growth” (Meadows et al. 1972) was the sober opposite. Experts can still be found on either side of this divide, but with climate change, we realize the limit is likely not energy per se. Instead, it is about finding an equilibrium temperature that allows ecosystems and biodiversity to thrive, and for humans to settle into curating the atmosphere, thus balancing our need for biodiversity with the land-use demands of energy, agriculture, housing, and leisure.

It is clear to many that we must figure out how to be the competent gardeners of a planet earth. As Bill McKibben famously argued in “The End of Nature,” (McKibben 1989) as a result of anthropogenic climate change, we now hold the fate of all other species in our hands. This makes trying to predict the future of energy far less important than acknowledging that the only viable option is to figure out how to succeed in managing the trade-offs. Either we create a balanced garden planet with humans actively involved in limiting our footprint, or we risk undermining the conditions under which humanity can coexist with all other species.

6 How Much Energy Do We Need?

The answer to this question is very dependent on the type of energy we will use in the future, and enormously dependent on where it comes from. Historically we speak of energy needs in units of primary energy—the energy content per ton of coal, per cubic foot of natural gas, or per barrel of oil.

The precipitous fall in the cost of batteries, and the emergence of viable electric vehicles, has enabled renewable electrification to seriously contend with fossil fuels. One convenience of fossil fuels is that you can store a lot of them, for a long time. At any given moment, a month or two’s supply of oil, coal, and natural gas is sitting in stockpiles, strategic reserves, and storage caverns. This storage allows us to get through winter, a stormy night, or supply chain shortages. Contrariwise, electricity must be used practically instantly the moment it is generated. But now viable batteries exist that can store electricity for days and weeks. With hydrogen, ammonia, and fossil fuel substitutes known as “electrofuels” (produced with excess electricity), we can now imagine storing electricity for the winter. Yet we must design our energy system for the winter, when solar insolation is the lowest. It might mean we have excess supply in the summer, but it is excess supply that has enabled the fossil fuel industry to balance supply and demand for the last century.

Why is this important? Because electricity is far more efficient than fossil fuels or chemical fuels. For example, with 1kWh of coal, by the time I burn it, run it through an electricity generator, and turn on a light bulb, I only get about 1/3 of a kWh of electricity powering my bulb. With natural gas, I might do better and get 1/2 of a kWh. Yet if I have solar-generated electricity stored in my battery then close to 90% of my original kWh might power my lightbulb. This efficiency advantage of electricity is true in all areas of energy. An electric vehicle uses approximately 1/3 or 1/4 of the energy of an equivalent internal combustion engine because it isn’t generating waste heat. A wind turbine or solar cell may not absorb all of the energy from the wind or sunshine, but it doesn’t create huge quantities of heat. The heat pump is another kind of electric technology that harnesses more energy from its surroundings than is fed to it with electricity. It can take air that feels cool and separate it into a small parcel of hot air and a large parcel of cold air. These heat pumps allow us to use 1 unit of electricity to generate 3 or 4 units of heat. This is far more efficient than using 1 unit of natural gas in exchange for 0.8–0.9 units of heat. Studies of global energy systems that look at high degrees of electrification powered by renewables (and even some nuclear) show that we could have all the energy benefits of our current lifestyles at less than 1/2 the energy input compared with fossil fuels.⁴⁻⁵ The average American uses the equivalent of 10 kW of power (a constant flux of 10 kJ of energy use per second) to power their life. The average southern European uses around 4 kW. The average Indian or African uses under 1 kW. Activist communities in Switzerland have tried to live on a self-imposed budget of 2 kW.⁶

It should be noted that energy economies owe more to fossil fuels than anything else. The International Energy Agency sounds very fancy but was founded as an organization of oil-producing and consuming nations. It isn’t exactly unbiased in the presentation of world energy futures. Indeed, many people look to Shell or BP or other fossil fuel-based companies for their energy economy forecasts, which struggle to look far beyond the status quo. The world energy economy is often described in Quads, or quadrillions of British thermal units, or MBOE (Millions of Barrels of Oil Equivalent). The S.I. units of energy are Joules and Watts. One is a unit of energy (the Joule), the other a unit of power (the Watt)—a rate at which something consumes power. We will know we have succeeded in an energy transition when the units we use to describe energy no longer refer to fossil fuels.

If we don’t all develop a penchant for flying cars and annual round-the-world-by-jet-plane holidays, then we can see pathways toward a high quality of life existing at 2–5 kW per person. The rate of growth of the world’s population has fallen much faster than most experts predicted, and indeed, 10 billion people is starting to look like the peak of our global population. Many countries have negative natural rates of population growth; and more education, particularly for women and girls, is stemming run-away population growth. 8–10 billion people consuming 2–4 kW of constant energy with high degrees of electrification does not seem impossible. This implies a 15–30 TW world, which is not hugely different from the ~20 TW world powered by fossil fuels today.

One can still find many libertarians or ideological conservatives who will argue that we can only thrive as a species if we have an abundance of cheap energy that enables us to meet every need and want, including reaching for stars with space travel. Many indigenous cultures found stability for thousands of years in societies that had enough energy to build lively cultures and even animus religions that balanced their needs with the species they relied upon for food. Whether the cultural balance falls towards societies that can balance their needs with those of other species or towards societies that believe God will provide and so ignore physical constraints and other species, will probably determine our fate.

7 Where Will All Our Energy Come From?

The good news is that we have no shortage of energy. The amount of solar radiation that makes it through the atmosphere and into our earth system is 85,000 terawatts. A terawatt (TW) is a trillion watts, or about the same power as one hundred billion LED lightbulbs. The amount of solar that hits the earth thus far surpasses the ~20 TW that we currently use, as well as our projected 15–30 TW electrified world.⁷

Fig. 9.3

Source by the author

Global renewable and natural energy flows

A summary of the potential of renewable or natural sources of energy is given in Fig. 9.3. The sun is the primary source of almost all our renewables—energy that can be replenished. The major player is solar (85,000 TW) and it is abundant wherever the sun shines. The sun heats the air and creates wind (3600 TW at all altitudes, around 400 TW that can be harnessed with turbines). The winds whip up waves (62 TW deep ocean, 3T W on coastlines) that can be captured by wave power generators. The sun evaporates water, which becomes clouds and rain, filling rivers that can be tapped for hydroelectricity (7 TW). As your feet know when walking on hot sand on a summer beach, the sun also heats the ground. This “ground-source” geothermal heat can be harvested year-round by a technology called “heat pumps” to keep buildings at an even temperature. Confusingly, this kind of geothermal energy differs from what people commonly think of, which is a closer relative of geysers and volcanoes and hot springs, and thus rare. Geothermal energy (32 TW) is not derived from solar but is remnant heat left over from the formation of the earth, with a little heat generated from radioactive decay thrown in for good measure. This creates extremely hot rock, which is accessible by drilling and can be used to create steam, driving a turbine to create electricity. The temperature difference between the top and the bottom of the ocean could also create energy in the ocean thermal gradient (100 TW) but it is a small temperature difference that is very difficult to harness efficiently.

The sun is also critical to photosynthesis, which creates biomass (wood, algae, grasses, forestry and agricultural waste, food waste, human waste, and other biological matter) which can be converted to biofuels (65 TW in all land based bio, and 25 TW in the ocean) to supply energy to hard-to-decarbonize sectors like long-haul aviation. All of our fossil fuels are incredibly old biofuels that have been buried and concentrated over time. It is estimated that fossil fuels accumulate at a natural rate of 0.01–0.05 TWh. about 1000 times slower than the rate at which we use them.

Nuclear energy isn’t renewable—there is a finite amount of fissile material in the world (primarily types of plutonium and uranium) (Fetter 2009). Estimates vary between 200 and 1000 years, depending on what portion of the supply it will meet, and whether we stick with light water reactors that don’t produce weaponizable byproducts or whether we move to breeder reactors that do. Although we could get by without nuclear energy, it is available to us, and useful in places that don’t have enough land area to support wind and solar infrastructure.

8 The Impacts of Our Energy Options on Biodiversity

We have a host of energy options. Let’s pause to contemplate what they are.

As we saw above there is enough solar energy, or wind energy, to power all of humanity’s energy needs in perpetuity if we assume that we are a highly electrified world and the total number is 15–30 TW. We could also power it for quite a long time, centuries at least, with nuclear power. In reality it will be a mix.

Given our needs, we’ll have to make electricity wherever we can—understanding that some sources are easier, cheaper, and more convenient than others. Some places have better wind, some have better solar, and some don’t have enough of either and will probably need some nuclear or long distance transmission of renewables from somewhere else. Where there are rivers, hydroelectricity, which provides nearly 7% of electricity in the U.S. today, and 16% globally, will be critical. Where there are oceans, wave and tidal power will help at the margins. Offshore wind is likely to be the big producer from the oceans, particularly in places with relatively shallow (50 m) continental shelves.

Solar, wind, and nuclear are the resources we have that far exceed our demands. Solar and wind are the cheapest and have fewer complications than nuclear energy. There is so much money in the fight over the future of our energy supply that an enormous brouhaha emerged in the climate and energy world when Mark Jacobson (Hanley 2018) of Stanford University and some colleagues proposed that the world could run 100% on Water, Wind and Solar (WWS) (Jacobson et al. 2015). The critique (Clack 2017) was vicious, and even by academia’s petty standards, the rebuttal was even more vicious (Jacobson et al. 2017)⁸. It ended in a lawsuit. I believe history will side with Jacobson, and that we will be able to do this—others agree with me (Mai et al. 2012). Much of the critique is that we can’t have reliability in an all-renewables world. There is every reason to believe it’s easier than we think to turn these intermittent sources into a reliable energy supply. You do have to think about supply and demand, and my critique of this academic storm is that all should have paid more attention to both sides of the equation. Jacobson may be too anti-nuclear, but his critics are too anti-future.

We are blessed with enough zero-carbon energy to meet our needs and even expand our wants; we just have to harness that energy sensibly while minimizing potential harm to biodiversity caused by flooding river valleys for hydroelectric dams and destroying desert habits for solar developments. For example, rooftop solar is far less damaging to biodiversity than destruction of precious remaining natural habitats.

Regardless of the minutiae of exactly how we decarbonize, electricity will power civilization, and solar and wind will do the heavy lifting. The no-regrets pathway to quickly transform our fossil-fuel-powered world to a world powered mostly by electricity is a combination of a majority of renewables (solar, wind, hydro, geothermal) with moderate nuclear and some biofuels as a backstop. The balance of those things will vary geographically and can be determined largely by market forces and public opinion about how to use land. The balance of power (energy nerds are always good for an energy pun!) will be determined by how well we use storage to smooth out the variability of renewables.

8.1 How Much Land Will We Need to Use?

Our landscapes will look different when we make this switch to renewable energy. Solar panels and windmills will become pervasive in our cities, suburbs, and rural areas. To power all of America on solar, for example, would require about 1% of the land area dedicated to solar collection—about the same area we currently dedicate to roads or rooftops (see Figs. 9.4 and 9.5). Our rooftops, parking spaces, and commercial and industrial buildings can do double duty as solar collectors. Similarly, we can farm wind on the same land that we farm crops.

Fig. 9.4

Source by the author

Land-use by state in categories defined by BLS

Fig. 9.5

Source by the author; reprinted courtesy of The MIT Press from Electrify: An Optimist’s Playbook for Our Clean Energy Future by Saul Griffith

Illustrative areas of the U.S. land use, including reference areas for renewables

In round figures, to electrify the whole U.S. economy we’ll need to generate 1800 GW. To generate all of that with solar would take about 15 million acres of solar panels. You can check our numbers: we assume a real fill fraction of 60%, a capacity factor of 24%, and a cell efficiency of 21%, so to get 1800 GW we need 15 million acres, or ~1 megawatt/acre. To harness the same amount of energy with wind power alone would take around 100 million acres planted with wind turbines. For reference, the U.S. covers 2.4 billion acres.

Some people talk about the size of the solar cell we will build in the center of the Arizona desert, and how it will power all of America. But that’s not actually how this job will get done because of the expense of transmission (long distance) and distribution (short distance), not to mention the destruction of biodiversity that would be required. The installations will be everywhere, so it is more illustrative to compare the amount of solar and wind we need to other ways humans use land. Since a lot of land will be required, it is worth looking at surfaces and activities that can do two jobs at once.

Let’s first look at solar. In Table 9.1 we see the U.S. acreage of rooftops, roads, and parking spaces—all places where we could install solar panels. There are details about how to effectively use these land areas for renewable generation, but these are merely meant for comparison. For instance, solar paving of roads gets a lot of attention but it isn’t a great idea due to the dirt and abuse of driving cars on top of solar cells. It is better to think about lofting panels over roads, above parking spots, and filling the medians.

Table 9.1 Estimates of land area occupied by our 6 million commercial buildings, 120 million homes, 8.8 million lane-miles of roads, and at least 1 billion(!) parking spaces

Table 9.1 totals 21 million acres. If we use all solar, we would need nearly 15 million acres for panels to produce all our electricity needs. This is more than two-thirds of all our available roofs, roads, and parking spaces. We will need to be putting solar panels wherever we can fit them. There is a camp of environmentalists that believes we’ll power the world with distributed solar, but the numbers tell a simple story: we’ll need all of the distributed energy we can harness and we’ll need industrial installations of solar and wind as well.

Fortunately, we can also rely on abundant wind resources in the U.S. Let us consider where wind turbines can work for us. Like solar, turbines can do double duty as they harness wind on agricultural and rangelands, among others. Table 9.2 profiles overall land use in the United States, and how it’s broken up.

Table 9.2 From United States department of agriculture, economic research service (major land uses)

Right away we can see that we have plenty of cropland, where we can also put wind turbines. Idle cropland is ideal for turbines (and perhaps for generating income for farmers). We also have massive amounts of grasslands, pastures, and rangelands where we can place wind turbines. If we set aside land used for urban areas, transportation, defense and industrial, rural parks and wildlife, and forest-use land, we still have about 390 million acres we could use for wind turbines. Some places will be more amenable to wind than others—because of prevailing winds and politics.

There can be no “not in my backyard” with solar and wind energy. Consider that fossil fuels are pervasive and pollute everyone’s back yards—in the air, the water, the soil. Over the decades, we have learned to live with a lot of changes in our landscape, from electricity lines and highways to condos and mini-malls. We will also have to live with a lot more solar panels and wind turbines. The trade-offs will be cleaner air everywhere, cheaper energy, and most importantly, we will be saving that land and landscape for future generations. We will have to balance land use with energy needs. But we can see that we are blessed with vast land resources in the U.S., enough that a combination of solar and wind will give us plenty of energy to electrify our economy.

8.2 Nuclear

Nuclear energy can work, but 50 years of debating it have passed and we still haven’t agreed on the best way to handle proliferation and waste issues. It’s not “too cheap to meter,” as was once predicted (Wellock 2016); in fact, it is likely more expensive than renewables. The exact costs depend on whom you ask. For instance, the operating costs of a particular plant can be impressively low. On the other hand, many think the costs should include the military and disposal expenses necessary to maintain a safe nuclear fleet, which significantly increasing costs. There are many more examples of such conflicts, leaving the true costs as a matter of considerable debate.

Nuclear has certainly been a reliable source of baseload power. Baseload is the most reliable resource that you are least likely to lose or turn off. Experts now often argue whether baseload is as important as previously thought (Diesendorf 2016). We likely need less baseload power than people think, and perhaps none at all, because of (1) the inherent storage capacity of our electric vehicles; (2) the shiftable thermal loads in our homes and buildings; (3) commercial and industrial opportunities to load-shift and store energy; and (4) the potential capacity of back-up biofuels and various batteries.

The approximately 60 nuclear facilities and 100 reactors in the U.S. already provide roughly 20% (about 100GW) of all our delivered electricity (around 450 GW.) The problem is that nuclear plants take decades to plan and build. In 2016, Watts Bar Unit 2 was connected to the grid after 43 years from the beginning of construction to grid connection⁹. It was the first new reactor in the U.S. since 1996¹⁰. Only a relative handful of new plants are being planned. Quickly scaling up nuclear power would be difficult.

Another highly under-appreciated problem is that nuclear power plants use river or ocean water to cool down, which ends up heating the water to levels that are deleterious to the fish and plants. 40% of water in the U.S. passes through the cooling cycles of thermoelectric power plants—this ultimately would limit the amount of nuclear power we could deploy with current technology.

We could build nuclear plants faster. We could make them cost less by changing the regulatory environment since the interest rate on the money borrowed to build a nuclear plant can amount to a significant cost addition. We could develop next-generation technologies. We could use mass-production techniques and economies of scale to lower their cost. But that’s a lot of what-ifs. It is unlikely that we’ll collectively achieve the conviction to build much more nuclear power before the combination of renewables with battery storage proves itself to be more cost-effective and politically favorable.

Nuclear power is so fraught with problems that Japan shut down its plants. So did Germany. China is also slowing down on nuclear technology. This isn’t because nuclear doesn’t work (it does) but because the socio-political—ecological-economic question marks that surround nuclear make it a long, hard road. And it’s far more costly than solar. The DOE itself has set targets of 5 ¢/kWh for rooftop solar, 4 ¢ for commercial solar, and 3 ¢/kWh for utility-scale solar by 2030 (FOA 2020).

Still, it’s unlikely we’ll eliminate nuclear energy in the U.S. for reasons of national security. Unless we completely disarm, it’s unrealistic to imagine the U.S. pulling out of nuclear power altogether. To address climate change, we’ll likely mildly increase nuclear (fission) power capacity in the U.S., but it probably won’t become the dominant energy source for all the reasons we’ve explained. In other countries with very high population density or a lack of renewable resources, nuclear or imported renewables are the only realistic options.

The world could power itself without nuclear, but for reasons of national security, high population densities, and predictability of supply, pragmatically the world will power some of itself with nuclear. It would be irresponsible to add a lot more nuclear without a lot more investment in improving the technology, waste processing, and security.

There are multiple fusion energy projects and start-ups that have reasonable approaches to the long sought-after goal of fusion energy. To name one, Commonwealth Fusion has a strong and viable pathway to fusion energy, but they themselves admit the challenges of time and cost. If we believe their rigor and claims of 5 ¢/kWh generation and the timeline of their first installed prototype—2032—it is still a bit expensive, and not exactly on the timeline required for limiting the world to only a 1.5 °C increase. Fusion will likely succeed eventually. It may have a dark side however. The wonderful thinker and author, George Dyson (son of physicist Freeman Dyson) poses the question of what humans would do if energy was so cheap we could move mountains on a whim? We probably wouldn’t resist simply moving mountains. Fusion could be a get out of jail free card energy-wise, but would it merely allow us to dominate nature in a way that would destroy it? Think about the consequences of fusion-powered bulldozers. Humans once had the arrogance to propose building the Panama canal with lots of little nuclear explosions…

9 Conclusion: Thinking Globally

By electrifying all vehicles, all heating systems, and industry, the U.S. economy could run on around 40% of the energy it does today, at an energy cost of around 4000 W of constant power per person. In a world of 10 billion people, where we each consume 2000–4000 W of constant power, giving everyone a European or North American quality of life via a nearly all-electric energy system, we can estimate our impact. Good solar cells with high coverage could be installed and gather 40 W per square meter of land they occupy. At the high end of our power per capita range, this means each individual would need around 100 square meters of land covered with their pro-rata solar installation. A 100% solar powered, electric world with European and American levels of energy services would thus need 0.5% of the world’s land dedicated to solar cells. For better or worse there are already 65,000,000 km of roads in the world. Assuming they average a narrow two lane road of 6 m width, that’s about 0.35% of global land area. Assuming a humble 25 m² or 250 ft² per person of living space, our homes cover about 0.25% of global land area. All settlement and infrastructure of humans are estimated at 1%. If we used our buildings and structures as a large part of our solar energy generation system, it is clear that achieving the amount of solar required to power the world is not unreasonable. Obviously we won’t exclusively use solar energy, and dual use of agricultural land with wind and higher energy density nuclear installations will make this goal even more achievable.

Let us put these land use requirements in context with global land use statistics (Fig. 9.6). The land use requirement for all of our energy could be satisfied with less than 2% of the land we grow and graze livestock on. We can look at the history of land use in Fig. 9.7. It is fairly obvious that the land use impact of creating our energy is dwarfed by our agricultural practices. While it is important to be concerned about land-use impact of energy, it is even more important to reign in our voracious appetite for land to feed our collective voracious appetite. The very steep increase in land use for cropland and grazing land through the nineteenth and twentieth centuries cannot continue if we wish to retain any wildland for other species. It should also be obvious that co-locating solar on land that has already been compromised by human intervention is the win–win path.

Fig. 9.6

Global land use

Fig. 9.7

History of global land use

In 2020, the world consumed a little more than 10 trillion kilograms of fossil fuels. That’s around 1300 kg of fossil fuels per person, planet-wide. Are we going to be causing more or less damage to the planet if we use renewables? For the purposes of this thought experiment, let’s again take our 4000 W per person energy budget. This is around 125 GJ/year/person, much more than the current 75.7 GJ/year/person, and taking into account the efficiency of electrification, this means around 5 times as much effective energy use per person, while dramatically improving quality of life. We can make an estimate of the tonnages of things required to sustain that level of energy consumption. Assume a mix of 50% solar and 50% wind energy, and storage of 50% of that energy in Lithium batteries. Assuming a 20 year lifetime for solar, a 25 year lifetime for wind, and 10 year lifetime (or 3700 cycles) for the batteries, the total weight per year per person of things that need to be supplied to meet their energy supply is around 68 kg. Unlike fossil fuels where there is no recycling, we can recycle most of the materials used in these machines. If we develop good recycling for all three of these things, say a rate of 80% which should be achievable, it would mean about 13.5 kg per year per person of stuff. Given that some of the energy will be hydroelectric, geothermal, and nuclear, this number will be even lower.

So, there is quite a good news story here. We could improve everyone’s quality of life with an average of 5 times as much energy per person, and achieve it with only around 1% of the material we currently use in supplying our global energy needs. We just need the willpower to wean ourselves off of fossil fuel and develop sustainable strategies for renewable energy.