Chapter 11. What We Learned

[See also an updated (March 2024) version of this chapter: We Need a Plan for the Transition to Renewable Energy.]

The authors began this book project with some general understanding of the likely energy transition constraints and opportunities; nevertheless, researching and writing Our Renewable Future has been a journey of discovery. Along the way, we identified not only technical issues requiring more attention, but also important implications for advocacy and policy. What follows is a very short summary, tailored mostly to the United States, of what we’ve learned.

We Really Need a Plan; No, Lots of Them

Germany has arguably accomplished more toward the transition than any other nation, largely because it had a plan—the Energiewende, which we discussed in chapter 3. This plan targets a 60 percent reduction in all fossil fuel use (not just in the electricity sector) by 2050, achieving a 50 percent cut in overall energy use through efficiency in power generation, buildings, and transport. It is not a perfect plan, in that it really should aim higher than 60 percent. But it is certainly better than nothing, and the effort is off to a good start. The United States does not have an equivalent official plan. Without it, we are at a significant disadvantage.

What would a plan do? It would identify the low-hanging fruit, show how resources need to be allocated, and identify needed policies. We would of course need to revise the plan frequently as we gained practical experience (as Germany is doing).

What follows are some components of a possible plan, based on work already done by many researchers in the United States and elsewhere; far more detail (with timelines, cost schedules, and policies) would be required for a fleshed-out version. We’ve grouped tasks into levels of difficulty; work would need to commence right away on tasks at all levels, but for planning purposes it is useful to know what can be achieved relatively quickly and cheaply, and what will take long, expensive, sustained effort.

Level One: The “Easy” Stuff

Nearly all energy transition analysts agree that the easiest way to kick-start the transition would be to replace coal with solar and wind power for electricity generation. That would require building lots of panels and turbines while regulating coal out of existence. Distributed generation and storage (rooftop solar panels with home- or office-scale battery packs) will help. Replacing natural gas will be harder, because gas-fired “peaking” plants are often used to buffer the intermittency of industrial-scale wind and solar inputs to the grid (see “Level Two”).

As we’ve noted repeatedly, electricity accounts for less than a quarter of all final energy used in the United States (see fig. 3.1). What about the rest of the energy we depend on? Since solar, wind, hydro, and geothermal produce electricity, it makes sense to electrify as much of our energy usage as we can. For example, we could heat and cool most buildings with electric air-source heat pumps (replacing natural gas- or oil-fueled furnaces). We could also begin replacing all our gas cooking stoves with electric stoves.

Transportation represents a large swath of energy consumption, and personal automobiles account for most of that. We could reduce oil consumption substantially if we all drove electric cars (replacing 250 million gasoline-fueled automobiles will take time and money but will eventually result in energy and financial savings). But promoting walking, bicycling, and public transit will take much less time and investment, and be far more sustainable in the long term.

Buildings will require substantial retrofitting for energy efficiency (this will again take time and investment but will offer still more opportunities for savings). Building codes should be strengthened to require net-zero energy or near-net-zero-energy performance for new construction. Zoning codes and development policy should encourage infill development, multifamily buildings, and clustered mixed-use development. More energy-efficient appliances will also help.

The food system is a big energy consumer, with fossil fuels used in the manufacturing of fertilizers, in food processing, and transportation. We could reduce a lot of that fuel consumption by increasing the market share of organic (i.e., not using synthetic fertilizers, herbicides, and pesticides) local foods. While we’re at it, we could begin sequestering enormous amounts of atmospheric carbon in topsoil by promoting farming and land management practices that build soil rather than depleting it.

If we got a good start in all these areas, we could achieve at least a 40 percent reduction in carbon emissions in ten to twenty years.

Level Two: The Harder Stuff

As we’ve seen, solar and wind technologies have a drawback: they provide energy intermittently. When they become dominant within our overall energy mix, we will have to accommodate that intermittency in various ways. We’ll need substantial amounts of grid-level energy storage as well as a major grid overhaul to get the electricity sector to 80 percent renewables (thereby replacing natural gas in electricity generation). We’ll also need to start timing our energy usage to coincide with the availability of sunlight and wind energy. That in itself will present both technological and behavioral hurdles.

Electric cars aside, the transport sector will require longer-term and sometimes more expensive substitutions. We could reduce our need for cars (which require a lot of energy for their manufacture and decommissioning) by densifying our cities and suburbs and reorienting them to public transit, bicycling, and walking. We could electrify all motorized human transport by building more electrified public transit and intercity passenger rail links. Heavy trucks could run on fuel cells, but it would be better to minimize trucking by expanding freight rail. Transport by ship could employ sails to increase fuel efficiency (this is already being done on a tiny scale), but relocalization or deglobalization of manufacturing would be a necessary co-strategy to reduce the need for shipping.

Much of the manufacturing sector already runs on electricity, but some critical aspects don’t—and many of these will offer significant challenges. Many raw materials for manufacturing processes either are fossil fuels (feedstocks for plastics and other petrochemical-based materials, including lubricants, paints, dyes, pharmaceuticals, etc.) or currently require fossil fuels for mining or transformation (e.g., most metals). Considerable effort will be needed to replace fossil fuel–based materials and to recycle nonrenewable materials more completely, significantly reducing the need for mining.

If we did all these things, while also building far, far more solar panels and wind turbines, we could achieve roughly an 80 percent reduction in emissions compared to our current level.

Level Three: The Really Hard Stuff

Doing away with the last 20 percent of our current fossil fuel consumption is going to take still more time, research, and investment—as well as much more behavioral adaptation. Just one example: we currently use enormous amounts of concrete for all kinds of construction activities, and concrete requires cement. As we’ve seen, cement making needs high heat, which could theoretically be supplied by sunlight, electricity, or hydrogen—but that will entail a nearly complete redesign of the process.

While with Level One we began a shift in food systems by promoting local organic food, driving carbon emissions down further will require finishing that job by making all food production organic, and requiring all agriculture to build topsoil rather than depleting it. Eliminating all fossil fuels in food systems will also entail a substantial redesign of those systems to minimize processing, packaging, and transport.

The communications sector—which uses mining and high heat processes for the production of phones, computers, servers, wires, photo-optic cables, cell towers, and more—presents some really knotty problems. The only good long-term solution in this sector is to make devices that are built to last a very long time and then to repair them and fully recycle and remanufacture them when absolutely needed. The Internet could be maintained via the kinds of low-tech, asynchronous networks now being pioneered in poor nations, using relatively little power.^[1]

Back in the transport sector: we’ve already made shipping more efficient with sails, but doing away with petroleum altogether will require costly substitutes (fuel cells or biofuels). One way or another, global trade will almost inevitably shrink. There is no good drop-in substitute for aviation fuels; we may have to write off aviation as anything but a specialty transport mode. Planes running on hydrogen or biofuels are an expensive possibility, as are dirigibles filled with (nonrenewable) helium, any of which could help us maintain vestiges of air travel. Paving and repairing roads without oil-based asphalt is possible though it will require an almost complete redesign of processes and equipment.

The good news is that if we do all these things, we can get to beyond zero carbon emissions; that is, with sequestration of carbon in soils and forests, we could actually reduce atmospheric carbon with each passing year.

Plans will look different in each country, so each country (and each state) needs its own.

Scale Is the Biggest Challenge

When we performed the thought exercise of starting with a blank page and designing a renewable energy system that (1) has minimal environmental impacts, (2) is reliable, and (3) is affordable, we found this could easily be done in several different ways—as long as relatively modest amounts of energy were needed. Once current US scales of energy production and usage were assumed we found we had to sacrifice the environment (because of the vast tracts of land needed for siting wind turbines and solar panels), reliability (because of the intermittency of solar and wind), or affordability (because of the need for storage or capacity redundancy). Power is a secondary hurdle: ships and airplanes require energy-dense fuels because they are maneuvering such enormous weights. Renewable energy resources can supply the needed power, but once again scale is the issue: building and operating a few hydrogen-powered airplanes for specialized purposes would certainly be technically feasible, but operating fleets of thousands of commercial planes using hydrogen fuel is daunting from both technical and economic perspectives

It’s Not All About Solar and Wind

These two energy resources have been the subjects of most of the discussion surrounding the renewable energy transition. Prices are falling, rates of installation are high, and there is a large potential for further growth (fig. 11.1). However, as we have pointed out repeatedly, the inherent intermittency of these energy sources will pose increasing challenges as percentage levels of penetration into overall energy markets increase. Other renewable energy sources—hydropower, geothermal, and biomass—can more readily supply controllable base load power, but they have much less opportunity for growth.

Hopes for high levels of wind and solar are therefore largely driven by the assumption that industrial societies can and should maintain very high levels of energy use. Once again, the challenge is scale: if energy usage in the United States could be scaled back significantly (70 to 90 percent) then a reliable all-renewable energy regime—based more upon hydro, geothermal, and biomass, but with solar and wind used in situations where intermittency is not a problem—becomes much easier to envision and cheaper to engineer.

We Must Begin Preadapting to Having Less Energy

As we saw in chapter 6, it is unclear how much energy will be available to society at the end of the transition: there are many variables (including rates of investment and the capabilities of renewable energy technology without fossil fuels to back them up and to power their manufacture, at least in the early stages). Nevertheless, given all the challenges involved, it would be prudent to assume that people in wealthy industrialized countries will have less energy (even taking into account efficiencies in power generation and energy usage) than they would otherwise have, assuming a continuation of historic growth trends.

This conclusion is hard to avoid when considering the speed and scale of reduction in emissions actually required to avert climate catastrophe. As climate scientist Kevin Anderson points out in an upcoming Nature Geoscience paper: “According to the IPCC’s Synthesis Report, no more than 1,000 billion metric tons (1,000 Gt) of CO₂ can be emitted between 2011 and 2100 for a 66% chance (or better) of remaining below 2°C of warming (over preindustrial times). . . . However, between 2011 and 2014 CO₂ emissions from energy production alone amounted to about 140 Gt of CO₂.” Subtracting realistic emissions budgets for deforestation and cement production, “the remaining budget for energy-only emissions over the period 2015–2100, for a ‘likely’ chance of staying below 2°C, is about 650 Gt of CO₂.^[2]

That 650 gigatons of carbon amounts to less than nineteen years of continued business-as-usual emissions from global fossil energy use. The notion that the world could make a complete transition to alternative energy sources, using only that nineteen-year fossil energy budget, and without significant reduction in overall energy use, might be characterized as optimism on a scale that stretches credulity.

The “how much will we have?” question reflects an understandable concern to maintain current levels of comfort and convenience as we switch energy sources. But in this regard it is good to keep ecological footprint analysis in mind.

According to the Global Footprint Network’s Living Planet Report 2014, the amount of productive land and sea available to each person on Earth in order to live in a way that’s ecologically sustainable is 1.67 global hectares.^[3] The current per capita ecological footprint in the United States is 6.8 global hectares (if the entire world population lived at this footprint it would require four planet Earths; see fig. 11.2). Asking whether renewable energy could enable Americans to maintain their current lifestyle is therefore equivalent to asking whether renewable energy can keep us living unsustainably. The clear answer is: only temporarily, if at all—so why attempt the impossible? We should aim for a sustainable level of energy and material consumption, which on average is significantly lower than at present.

Efforts to preadapt to shrinking energy supplies have understandably gotten a lot less attention from activists than campaigns to leave fossil fuels in the ground, or to promote renewable energy projects. But if we don’t give equal thought to this bundle of problems, we will eventually be caught short, and there will be significant economic and political fallout.

So what should we do to prepare for energy reduction? Look to California: its economy has grown for the past several decades while its per capita electricity demand has not. The state encouraged cooperation between research institutions, manufacturers, utilities, and regulators to figure out how to keep demand from growing by changing the way electricity is used.^[4] This is not a complete solution (California’s population has grown during this period, so its total electricity consumption has also grown; we do not have a good example of absolute reduction in aggregate energy use). Nevertheless this may be one of the top success stories in the energy transition so far, rivaling that of Germany’s Energiewende. It should be copied in every state and country.

Consumerism Is a Problem, Not a Solution

Current policy makers see increased buying and discarding of industrial products as a solution to the problem of stagnating economies. With nearly 70 percent of the US economy tied to consumer spending,^[5] it is easy to see why consumption is encouraged. Historically, the form of social and economic order known as consumerism largely emerged as a response to industrial overproduction—one of the causes of the Great Depression—which in turn resulted from an abundant availability of cheap fossil energy.^[6] Before, but especially after, the Depression and World War II, the advertising and consumer credit industries grew dramatically as means of stoking product purchases, and politicians of all political persuasions joined the chorus, urging citizens to think of themselves as “consumers,” and to take their new job description to heart.

If the transition to renewable energy implies a reduction in overall energy availability, if mobility is diminished, and if many industrial processes involving high heat and the use of fossil fuels as feedstocks become more expensive or are curtailed, then conservation must assume a much higher priority than consumption in the dawning post-fossil-fuel era. If it becomes more difficult and costly to produce and distribute goods such as clothing, computers, and phones, then people will have to use these manufactured goods longer, and repurpose, remanufacture, and recycle them wherever possible. Rather than a consumer economy, this will be a conserver economy.

The switch from one set of priorities and incentives (consumerism) to the other (conservation) implies not just a major change in American culture but also a vast shift both in the economy and in government policy, with implications for nearly every industry. If this shift is to occur with a minimum of stress, it should be thought out ahead of time and guided with policy. We see little evidence of such planning currently, and it is not clear what governmental body would have the authority and capacity to undertake it. Nor do we yet see a culture shift powerful and broad-based enough to propel policy change.

The renewable economy will likely be slower and more local. Economic growth may reverse itself as per capita consumption shrinks; if we are to avert a financial crash (and perhaps a revolution as well), we may need a different economic organizing principle. In her recent book on climate change, This Changes Everything, Naomi Klein asks whether capitalism can be preserved in the era of climate change; while it probably can (capitalism needs profit more than growth), that may not be a good idea because, in the absence of overall growth, profits for some will have to come at a cost to everyone else. And this is exactly what we have been seeing in the years since the financial crash of 2008 (fig. 11.3).

The idea of a conserver economy has been around at least since the 1970s, and both the European degrowth movement^[7] and the leaders of the relatively new discipline of ecological economics^[8] have given it a lot of thought. Their insights deserve to be at the center of energy transition discussions.

Population Growth Makes Everything Harder

A discussion of population might seem off-topic for this book. But if energy and materials (which represent embodied energy) are likely to be more scarce in the decades ahead of us, population growth will mean even less consumption per capita. And global population is indeed growing: on a net basis (births minus deaths) we are currently adding 82 million humans to the rolls each year,^[9] a larger number than at any time in the past, even if the percentage rate of growth is slowing.

Population growth of the past century was enabled by factors—many of which trace back to the availability of abundant, cheap energy and the abundant, cheap food that it enabled—that may be reaching a point of diminishing returns. Policy makers face the decision now of whether to humanely reduce population by promoting family planning and by public persuasion, by raising the educational level of poor women around the world and giving women full control over their reproductive rights, or by letting nature deal with overpopulation in unnecessarily brutal ways. For detailed recommendations regarding population matters, consult population organizations such as Population Institute^[10] and Population Media Center.^[11] Population is a climate and energy issue.

Fossil Fuels Are Too Valuable to Allocate Solely by the Market

Our analysis suggests that industrial societies will need to keep using fossil fuels for some applications until the very final stages of the energy transition—and possibly beyond, for nonenergy purposes. Crucially, we will need to use fossil fuels (for the time being, anyway) for industrial processes and transportation needed to build and install renewable energy systems.^[12] We will also need to continue using fossil fuels in agriculture, manufacturing, and general transportation, until robust renewable energy–based technologies are available. This implies several problems.

As the best of our remaining fossil fuels are depleted, society will by necessity be extracting and burning ever-lower-grade and/or harder-to-get coal, oil, and natural gas. We see this trend already far advanced in the petroleum industry, where virtually all new production prospects involve tight oil, tar sands, ultraheavy oil, deepwater oil, or Arctic oil—all of which entail high production costs and high environmental risk as compared to conventional oil found and produced during the twentieth century—and refining what are sometimes heavier, dirtier fuels (in the case of tar sands) creates ever more co-pollutants that have a disproportionate health impact and burden on low-income communities. The fact that the fossil fuel industry will require ever-increasing levels of investment per unit of energy yielded has a gloomy implication for the energy transition: much of society’s available capital will have to be directed toward the deteriorating fossil fuel sector to maintain current services, just as much more capital is also needed to fund the build-out of renewables. Seemingly the only way to avoid this trap would be to push the energy transition as quickly as possible, so that we aren’t stuck two or three decades from now still dependent on fossil fuels that, by then, will be requiring so much investment to find and extract that society may not be able to afford the transition project.

But there is also a problem with accelerating the transition too much. Since we use fossil fuels to build renewables, speeding up the transition could mean an overall increase in emissions—unless we reduce other current uses of fossil fuels (if the pace of end-use electrification exceeds the pace of renewable energy electricity production growth, then this could also lead to higher emissions). In other words, we may have to deprive some sectors of the economy of fossil fuels before adequate renewable substitutes are available, in order to fuel the transition without increasing overall greenhouse gas emissions. This would translate to a reduction in overall energy consumption and in the economic benefits of energy use (though money saved from conservation and efficiency would hopefully reduce the impact), and this would have to be done without producing a regressive impact on already vulnerable and economically disadvantaged communities.

We may be entering a period of fossil fuel triage. Rather than allocating fossil fuels simply on a market basis (those who pay for them get them), it may be fairer, especially to lower-income citizens, to find ways to allocate fuels based on the strategic importance of the societal sectors that depend on them, and on the relative ease and timeliness of transitioning those sectors to renewable substitutes. Agriculture, for example, might be deemed the highest priority for continued fossil fuel allocations, with commercial air travel assuming a far lower priority. Perhaps we need not just a price on carbon, but different prices for different uses. We see very little discussion of this prospect in the current energy policy literature. Further, few governments even currently acknowledge the need for a carbon budget. The political center of gravity, particularly in the United States, will have to shift significantly before decision makers can publicly acknowledge the need for fossil fuel triage.

As fossil fuels grow more costly to extract, there may be ever-greater temptation to use our available energy and investment capital merely to maintain existing consumption patterns, and to put off the effort that the transition implies. If we do that, we will eventually reap the worst of all possible outcomes—climate chaos, a gutted economy, and no continuing wherewithal to build a bridge to a renewable energy future.

Everything Is Connected

Throughout the energy transition, great attention will have to be given to the interdependent linkages and supply chains connecting various sectors (communications, mining, and transport knit together most of what we do in industrial societies). Some links in supply chains will be hard to substitute, and chains can be brittle: a problem with even one link can imperil the entire chain. This is the modern manifestation of the old nursery rhyme, “for the want of a nail, the kingdom was lost.”

Consider, for example, the materials required to manufacture and operate a wind turbine. Figure 11.4 shows the various components, each with its own manufacturing sector somewhere in the world.

Planning will need to take such interdependencies into account. As every ecologist knows, you can’t do just one thing.^[13]

This Really Does Change Everything

Energy transitions change societies from bottom to top, and from inside out. From a public relations standpoint, it may be helpful to give politicians or the general public the impression that life will go on as before while we unplug coal power plants and plug in solar panels, but the reality will probably be quite different. During historic energy transitions, economies and political systems underwent profound metamorphoses. The agricultural revolution and the fossil-fueled industrial revolution constituted societal watersheds. We are on the cusp of a transformation every bit as decisive.

*          *          *

We end this book as we began it, by restating our firm conviction that the transition from fossil fuels to renewable energy is necessary and inevitable. But, as has been shown, this transition will not be an automatic or simple process. There are many potential roadblocks, some of which arise from simple inertia: companies—indeed, whole societies—will invest in fundamental changes to their ways of doing business only when they have to, and most are quite comfortable with their current fossil-fuel-dependent processes, supply chains, and of course sunk costs.

Studies claiming that a transition to renewable energy will be easy and cost-free may allay fears and thus help speed the transition. However, sweeping actual difficulties under the carpet also delays confronting them. Our society needs to start now to address the problems of energy demand adaptation, of balancing intermittency in energy supply from solar and wind (or, preferably, finding ways to use variable energy sources at the times of their greatest abundance), and of energy substitution in thousands of industrial processes. Those are big jobs, and ignoring them won’t make them go away.

If many of the unknowns in the renewable energy transition imply roadblocks and speed bumps, some could turn out to be opportunities, and we cheerfully acknowledge that many conundrums may be much more easily solved than currently appears likely. For example, it is conceivable that new technical advances could result in a zero-carbon cement that is cheaper to make than the current carbon-intensive variety.^[14] But that is extremely unlikely to happen until serious attention is given to the problem.

At the end of the renewable energy transition, if it is successful, we will achieve savings in ongoing energy expenditures needed for each increment of economic production, and we may be rewarded with a quality of life that is acceptable and perhaps preferable over our current one (even though, for most Americans, material consumption will be scaled back from its current unsustainable level). We will get a much more stable climate than would otherwise be the case, along with greatly reduced health and environmental impacts from energy production activities. However, the conversion to 100 percent renewable energy will not by itself solve other environmental issues facing us—including deforestation, land degradation, and species extinctions among others.

A point we have raised repeatedly is that possibly the most challenging aspect of this transition is its implication for economic growth: whereas the cheap, abundant energy of fossil fuels enabled the development of a consumption-oriented growth economy, renewable energy will likely be unable to sustain such an economy. Rather than planning for continued, unending expansion, policy makers must begin to imagine what a functional postgrowth economy could look like. Among other things, the planned obsolescence of manufactured goods must end, in favor of far more durable products that can be reused, repaired, remanufactured, or recycled indefinitely.

To us, given factors currently visible and the unknowns arrayed ahead, it seems wise to channel society’s efforts toward no-regrets strategies (that is, actions to save energy that make sense in view of a range of possible futures)—efforts that shift expectations, emphasizing quality of life over consumption; and efforts that result in increased community resilience. Even though it may be impossible to fully envision the end result of the renewable energy transition, we believe that it is essential for society to seek to gain a sense of its scope and general direction. That is why we have written this book.

One way or another, our descendants a few decades from now will inhabit an all- renewable world (or nearly so), and it will be a world that works differently, in many significant ways, from the world we know today. It could be a better world in which to live, or it could be much worse, depending on the decisions we make in the next decade or two. Right now society is putting off even the most obvious and pressing of those decisions (starting with a mandatory global cap on carbon emissions). Successive waves of problems and requirements for decision will follow. Failing to see those next waves from a distance only makes the worse possibilities for our renewable future more likely. We hope that this exploratory effort shines a light into the future implications of the renewable energy transition, so that we can start now to see and understand the territory, consider our options, and act intelligently.