At the People’s Climate March back last spring, all along that vast river of people, the atmosphere was electric. But electricity was also the focus of too many of the signs and banners. Yes, here and there were solid “System Change, Not Climate Change” – themed signs and banners. But the bulk of slogans on display asserted or implied that ending the climate emergency and avoiding climatic catastrophes like those that would occur a few months later—hurricanes Harvey and Irma and the mega-wildfires in the U.S. West—will be a simple matter of getting Donald Trump out of office and converting to 100-percent renewable energy.
The sunshiny placards and cheery banners promising an energy cornucopia were inspired by academic studies published in the past few years purporting to show how America and the world could meet 100 percent of future energy demand with solar, wind, and other “green” generation. The biggest attention-getters have been a pair of reports published in 2015 by a team led by Mark Jacobson of Stanford University, but there have been many others.
A growing body of research has debunked overblown claims of a green-energy bonanza. Nevertheless, Al Gore, Bill McKibben (who recently expressed hope that Harvey’s attack on the petroleum industry in Texas will send a “wakeup call” for a 100-percent renewable energy surge), and other luminaries in the mainstream climate movement have been invigorated by reports like Jacobson’s and have embraced the 100-percent dream.
And that vision is merging with a broader, even more spurious claim that has become especially popular in the Trump era: the private sector, we are told, has now taken the lead on climate, and market forces will inevitably achieve the 100-percent renewable dream and solve the climate crisis on their own. In this dream, anything’s possible; Jacobson even believes that tens of thousands of wind turbines installed offshore could tame hurricanes like Katrina, Harvey, and Irma.
The 100-percent dream has become dogma among liberals and mainstream climate activists. Serious energy scholars who publish analyses that expose the idea’s serious weaknesses risk being condemned as stooges of the petroleum industry or even as climate deniers. Jacobson has even suggested that he might take legal action against NOAA scientist Christopher Clack and twenty coauthors whose critical evaluation of his work was published by the Proceedings of the National Academy of Sciences in June.
Jacobson’s team and others cling to the idea of 100-percent conversion because they (rightly) want to eliminate fossil and nuclear energy, and they foresee that any future supply gap left by a shortfall in renewable generation is going to be filled by those dirty sources. That is indeed stated or implied by many of the opposing analyses, including the Clack study.
But the two sides also share other basic assumptions. They both seek to satisfy all future demand for energy solely through industrial production, technological improvements, efficiency, and markets, without any strict regulatory limits on the total quantity of energy consumed in production and consumption. The 100-percenters believe such a scenario is achievable while their critics conclude that it is not, but they agree on the ultimate goal: a permanent high-energy economy.
That part of the dogma, not the “100-percent” part, is the problem. America does need to convert to fully renewable energy as quickly as possible. The “100-percent renewable for 100 percent of demand” goal is the problem. Scenarios that make that promise, along with the studies that dissect them, lead me to conclude that, at least in affluent countries, it would be better instead to transform society so that it operates on far less end-use energy while assuring sufficiency for all. That would bring a 100%-renewable energy system within closer reach and avoid the outrageous technological feats and gambles required by high-energy dogma. It would also have the advantage of being possible.
Waking up from the dream
The pursuit of the 100-percent dream didn’t start with the 2015 Jacobson et al. papers, and critiques of it didn’t start with Clack et al. For example, there was a 2015 paper by Peter Loftus and colleagues that critically examined 17 “decarbonization scenarios.” Then earlier this year, a study by a group of Australian researchers led by B.P. Heard rated the feasibility of 24 published studies that describe 100-percent renewable scenarios.
The Heard group concluded that among the research papers they evaluated (which included several with Jacobson as lead author), none “provides convincing evidence that these basic feasibility criteria can be met.” They found a wide range of technical flaws in the proposed systems. Most scenarios assumed unprecedented and deeply unrealistic improvements in energy efficiency (in terms of kilowatt hours consumed per dollar’s worth of output). Because the chief renewable technologies, wind and solar, fluctuate continuously in their output and regularly drop to zero output, they must be backed up with large supplies of “base load” electricity if all demand is to be met without interruption; no studies managed this without ecologically destructive levels of biomass burning or wildly unrealistic estimates of hydroelectric output.
Scenarios did not account for the overcapacity and redundancy that will be needed if a high-energy economy is to function in an increasingly unpredictable global climate. (This year, the people of Texas, Florida, and the West in particular can attest to the deep impacts of that unpredictability.) Studies did not account for the expected four- to five-fold expansion of the power transmission infrastructure that will be required to accommodate renewable energy. And they did not address the difficulties of maintaining voltage and frequency of alternating current within extremely tight limits (a necessity in technologically dependent societies) when a large share of the supply is from wind and solar. This all adds up, writes the Heard team, to a systemic “fragility” that will render futile all attempts to deliver the promised output of electricity when it is needed.
The Loftus group found several of the same weaknesses in the studies they examined. But they singled out scenarios in papers by Jacobson and Delucchi, the World Wildlife Fund, and Worldwatch. Those scenarios had in common two assumptions that Loftus and colleagues regarded as out of the realm of reality: efficiency improving at as much as 3 to 4 times the historic rate, and buildup of renewable generation capacity at many times the rate at which today’s total electric generation capacity was built up in past decades. They concluded that it would be “premature and highly risky to ‘bet the planet’” on the achievement of scenarios like those.
In their PNAS publication, the one that prompted Jacobson to hint at a lawsuit, Clack et al. critically examined two papers from 2015, one of which was a widely hailed “roadmap” for plentiful, 100-percent renewable energy in all 50 United States. In addition to “modeling errors,” much of the Clack critique is aimed at the Jacobson group’s assumed ubiquitous deployment of technologies that either don’t yet exist or are only lightly tested and can’t be scaled up to the huge scales envisioned. They include underground thermal energy storage for virtually every building in the country, a full air transportation system run entirely on hydrogen(!), wind farms covering 6 percent of the entire land surface of the 48 contiguous states, an outrageous and unrealistic increase in ecologically harmful hydroelectric power, and a buildout of electricity generation capacity that hurtles along at 14 times the average rate of capacity expansion in the past half-century.
But even if it were physically possible to achieve all of those scaleups, and even if Congress found a way to repeal and replace Murphy’s Law, the full-blown 100-percent dream could not be realized. In a series of papers published since 2010 (e.g., a 2016 paper in Energy Policy), Patrick Moriarty and Damon Honnery of Monash University in Australia have identified several crucial factors that will limit the total global output of renewable electricity. For example, renewable technologies exploit the windiest or sunniest locations first, and, as they expand, they move into less and less productive territory. There, their construction and operation will require as much energy input as before, but their output will be lower.
Furthermore, because of inherently intermittent generation, much of the electric power from wind and solar will have to be stored using batteries, hydrogen, compressed air, pumped water, or other means. It will then have to be reconverted to electricity and transmitted from often remote regions to places where people and businesses are concentrated. The result is a severe shrinkage of the net energy available to society, because much energy is expended or lost during both conversion and transmission. Finally, all production of wind, solar, geothermal, biomass, and especially hydroelectric energy has an ecological impact on the landscapes where it occurs. So if we are to halt our degradation and destruction of the Earth’s natural ecosystems, it will be necessary to declare large areas off-limits to the energy sector.
Moriarty and Honnery show that given all of these factors, expansion of renewable energy will hit a brick wall, a point at which as much energy is required to install and operate electric facilities as they will end up generating in their operating lifetimes. But even before that point is reached, it will have become pointless to expand generation capacity that has lower and lower net output. They conclude that as a result, future renewable output “could be far below present energy use.”
What are we hoping for?
A generally overlooked but crucial point about high-energy, 100-percent renewable proposals is that they seek to meet future demand patterns in a way that would leave in place today’s great distortions in access to energy and other resources. The American economy would carry on uninterrupted with its overproduction, overconsumption, and inequality, while billions of people in poorer regions and countries would not get the access to energy that’s required for a minimally good quality of life.
The 100-percent scenarios themselves, as well as the critiques of them, hold one especially valuable lesson. Unintentionally, they show in stark terms why rich countries need to start planning to live in the renewable but lower-energy world envisioned by Moriarty and Honnery rather than the high-energy world that the mainstream 100-percent scenarios envision. The world that the latter scenarios would create, one focused on maintaining current profligate consumption levels, would not be a green and pleasant one. Herculean quantities of physical and mental labor power will have been expended, boundless physical resources (including vast tonnages of fossil fuels) will have been consumed, and countless entire ecosystems across the Earth’s surface will have been sacrificed to generate more electricity. All of that would make for a pretty grim world. With society having zeroed in singlemindedly on acquiring enough energy to keep driving, flying, and overproducing as much as we want, there’s no reason to expect that other problems, including enormous distortions in economic and political power and quality of life, along with racial and ethnic oppression, would have been solved.
Some in the climate movement believe in the 100-percent dogma and the dream it holds out: that the (affluent) American way of life can keep running forward in time and outward in space without breaking stride. There are others who know that to be an impossibly rosy vision but urge the movement to limit public discussion to such green dreams anyway, because talking about a regulated, low-energy economy would crush hope and enthusiasm at the grassroots.
The debate about hope ignores the relevant question: what are we hoping for? If our hope is to deploy solar and wind capacity that maintains indefinitely the current throughput of energy in the world’s affluent societies, then, yes, the situation is hopeless. But there can be other hopes that, although they’re looking dim for now, are at least within reach: that greenhouse warming can be limited sufficiently to allow communities around the world who are currently impoverished and oppressed to improve their lives; that access to food, water, shelter, safety, culture, nature, and other necessities becomes sufficient for all; or that exploitation and oppression of humans and nature be brought to an end.
There’s always hope, as long as we don’t confuse dreams with reality.