“The line between failure and success is so fine that we scarcely know when we pass it: so fine that we often are on the line and do not know it.”
The Electrical Review, 1895
In a 1795 series of letters on art and beauty, Friedrich Schiller, the German historian and poet, defined play as “the aimless expenditure of exuberant energy.” He thought that artists, children, and animals played when there was more food on the table. “When hunger no longer torments the lion, and no beast of prey appears for him to fight,” he wrote, “then his unemployed powers find another outlet. He fills the wilderness with his wild roars and his exuberant strength spends itself in aimless activity.” British philosopher Herbert Spencer later borrowed the notion and called it the “surplus energy theory.”
A surplus is what hunters and gatherers captured from fish-bearing rivers and nut-laden trees; it’s what early civilization expropriated from the sweat of slaves; and it’s what modern society fritters away in fueling billions of mechanical servants. Ralph Waldo Emerson, another poet, often said in his lectures that what a nation did with its “surplus produce,” or energy, defined its character: “One bought games and amphitheatres; one, crusades; one churches; one, villas; one horses; one, operas; one, tulips; ours buys railroads, ships, mills, and observatories.” Emerson, who lived at a time when muscle, wind, and animals still supplied most of the United States’ energy, would have been appalled both by how his country eventually spent its oil and by how quickly it exhausted its surpluses.
Energy experts largely avoided the topic of surplus in the first half of the twentieth century. But sociologist Fred Cott-rell, writing in the 1950s, attributed America’s exceptional development to the nation’s bountiful energy profits. Societies that picked high-energy berries expanded, explained Cottrell, while those that chased low-energy rabbits declined. “A stroller eating blackberries growing wild along the road” got back more energy than he spent. “On the other hand, a man who runs down a jackrabbit in an 80-acre field” would burn more calories than he captured. Low-energy societies that lived on sunlight, Cottrell argued, paid close attention to their gains and losses because energy debt invariably led to cultural disintegration. But in societies hooked on petroleum, wrote Cottrell, “the facts are extremely difficult to come by.” In fact, oil produced such rich surpluses that most people stopped thinking about energy altogether.
No recent academic has analyzed the significance of energy surpluses and net gains better than Charles Hall. In the 1980s, the plainspoken New England systems ecologist came up with the formula for energy return on energy investment (EROI). It’s a biological equation devoted to inputs and outputs, and it goes like this: “EROI = energy gained divided by energy required to get that energy.” The formula can also be expressed as “Energy returned to society divided by energy required to get, deliver, and use that energy.” If a civilization, a tribe, or a corporation secures more energy returns from an activity than it invests, then it enjoys high EROIs and has time to play. But when a nation—or, say, a salmon—uses more energy than it gets back, trouble or starvation follows. Another way to convey Hall’s measurement is to consider EROI as a percentage of fuel delivered to the global gas station. A unit of energy with an EROI of 100 puts 99% of that fuel to work at society’s service. A gallon of fuel with an EROI of 2 delivers only a 50 percent gain. A fuel with an EROI of 1:1 is obviously useless. That’s when the car stalls on the freeway. EROIs lower than 10 march a civilization progressively towards what is called the “net energy cliff.”
Why a salmon? Fish taught Hall much of what he knows about energy surpluses. The energy of fish tells a lean story. A rainbow trout, for instance, will position itself in a fast-moving stream to collect floating insects. The gamble works if the fish ingests more calories than it spends on fighting the current. The fastest-growing trout finds the ideal current, the one that delivers the most food with the least effort. A slow-growing and unlucky cousin might drift aimlessly and then die. In the world of both fish and humans, there is no life without some form of energy profit.
When Hall studied the movement of twenty-seven species of fish in North Carolina’s New Hope Creek in the 1970s, he made some energetic findings. He found that larger adult species moved upstream to spawn in the more productive shallow pools. Since the stream’s upper reaches also offered the adults’ offspring a rich nursery, the young didn’t have to spend many calories in search of food. Hall also discovered that for every unit of energy the fish spent migrating upstream, they returned at least four units to the next generation of fish. The flow of fish upstream also acted like a natural energy pipeline, delivering essential nutrients to forest and creek alike.
The ecologist next studied the tiny Pacific salmon smolts that migrated all the way to Alaska and the Aleutians. Hall wondered why these young fish didn’t just park themselves at the nutrient-rich mouth of the Fraser River and enjoy a free meal. Energy profits again figured into the answer. The salmon, he discovered, followed higher densities of zooplankton that moved up the coast toward Alaska. These concentrated balls of edible fish food ensured higher energy returns, faster growth, and better survival rates. Such findings convinced Hall that the world revolves around surplus energy: “Everything in life is about energy costs and energy gains,” he says.
The world’s global fisheries and the petroleum industry illustrate the importance of energy profits in startlingly similar ways. These two primitive-energy industries, obsessed with capture, could almost be twins: both are testosterone driven, highly subsidized, and prone to wild busts and booms. Half of all oil is traded internationally in tankers; 50 percent of all fish landings go to distant markets. Both industries lie about the quality of their resources. Just as China has overstated its catches to promote the illusion of endless growth for twenty years and thereby obscured the decline of global fisheries, so Saudi Arabia and Shell have lied about their oil reserves, masking declining reserves of light crude. Regulators for both industries, among the most corrupt in the world, have no or little regard for conservation.
There are key differences. One industry mines the revenue of sunshine, while the other exhausts ancient capital. Fishing once netted big fish, a renewable biomass that ate small fish that dined on tiny creatures energized by photosynthesis. Petroleum mining attacks nonrenewable stocks of stored solar energy. But tellingly, both industries began by netting the easy catches at the top of their respective pyramids. They hunted the big fish first because those provided the richest returns. While the oil industry targeted some 600 giant oil fields on land, fishers captured the largest species swimming in lakes and rivers. After cleaning out the richest pools, both industries packed their bags and moved offshore. Fisheries started the offshore trek 400 years ago; the oil business followed in the 1950s. Once the fishing industry had nearly exterminated the big fish such as ray, slipmouth, cod, and wolffish, it left the coastline for murkier, deeper waters and smaller prey. Industrial trawlers can fish to depths of 1,600 feet and lift boulders the size of Volkswagens off the ocean floor. The oil industry perforated dense shale rock with high-pressured blasts of water, sand, and chemicals to release small amounts of oil and gas or drilled miles under the ocean floor.
The global fishery catch, once thought inexhaustible, quietly topped out at 94 million tons in the 1980s and has since dropped precipitously. The oil industry, which deemed cheap oil endless, peaked at between 85 and 88 million barrels of oil a day around 2008. It can no longer grow without massive investments in costly unconventional and dirty fuels. Scientists generally agree that the world’s cheap, light, and easy oil will be exhausted by 2030 just as Canada’s northern cod fishery was in the 1990s.
Fisheries biologists estimate that the global fish industry has now netted and processed two-thirds of the ocean’s biomass. The first steam-powered trawler appeared in 1850. But it was oil and its attendant horsepower slaves that radically magnified the power of industrial fishing. The master resource caused the number of inanimate slaves on every fishing boat to explode after WWII, explains Daniel Pauly. The Paris-born marine biologist is the world’s foremost expert on global fisheries. What was once “a little boat bobbing in the water” now comes equipped with fish finders, sonar, scanners, electric winches and satellite feeds. “[These boats are] using technology designed to hunt submarines,” explains Pauly. “We are using war technology against fish and the outcome is preordained. A modern fishing boat is a tank.”
Yet studies done by J. Cutler Cleveland and colleagues on the New Bedford fleet, then harvesting the globe’s sixth-largest catch in tonnage, showed that as fishing vessels employed more inanimate slaves to get bigger and faster, their nets delivered smaller yields. Between 1963 and 1988, while horsepower per vessel increased from 252 to 624 horsepower (allowing longer fishing trips into deeper waters), the New Bedford fleet spent more diesel to capture less edible protein. Despite burning three hundred times more fuel in 1988, the fleet actually caught 30 percent fewer fish than it had twenty years earlier. Its edible protein EROI declined fivefold, though government subsidies masked the real costs of the decline.
Charles Hall began to wonder if the oil industry too was pulling in smaller catches by spending more oil. Earlier studies by geologist Marion King Hubbert had found persistent declines. In the 1930s, the industry recovered about 250 barrels per foot of exploratory drilling, but that surplus dropped to 40 barrels per foot in the 1950s, rising intermittently when new fields were drilled. After the industry drained large oil fields in the North Sea and Texas, then moved offshore and to Arctic frontiers like Alaska, Hall suspected there would be further declines. In 1980, he assigned the task of finding out to a graduate student, Cutler Cleveland, who produced an N-shaped graph that showed energy surpluses for oil going up and down like a yo-yo. “The yield per foot of drilling would reach a minimum and then jump back up, then down even more sharply,” recalls Hall. Puzzled, Hall then asked Cleveland to add the number of feet drilled per year to the study. Once he did, the graph looked like a snowball going downhill: the number of barrels recovered per foot had dropped from 50 in 1946 to 15 by 1978. “It looked just like the falling catch graph for the fisheries,” says Hall. The Wall Street Journal reported on the findings in 1981 under the headline “Increased Drilling for Oil May Consume More Energy Than It Gleans.”
Since then, Hall and his colleagues, including Cleveland and David Murphy, have refined their work on EROI. Hall considers the measurement a critical tool for shining light on the quality of energy available for a society. He notes that the global EROI for oil production delivered returns of 30 a century ago but stands today at less than 20. In 2006, the U.S. Department of Energy estimated that the U.S. oil production EROI had dropped to 10: the high energy costs of offshore drilling, heavy-oil pumping, and hydraulic fracturing ate up more surpluses. But the concept of emptier energy nets and their societal implications still gets little attention in government and academic circles. “We never got any money to do this,” says Hall. “It all happened on weekends or pro bono. No government agency is interested in the information. Most science, to be honest, promises some form of candy. EROI doesn’t do that and we don’t do that.”
In a 2011 collection of studies for the journal Sustainability, Hall offered a fuller picture of petroleum’s shrinking energy profits. Industry trends now look as dismal as disappearing stocks of wild salmon and tuna. Hall estimates that it took only one barrel of oil to find an incredible 1,200 more barrels in 1919. In today’s capital- and energy-intensive petroleum fishery, reduced to horizontal drilling and bitumen mining, industry spends one exploratory barrel to catch just 5 more petroleum fish. The energy return on the cost of producing the oil has also dropped. One barrel put another 24 in a pipeline in 1954; today the yield is 11. Oil’s initial bounty and formidable EROI, says Hall, “had a great deal to do with a tremendous increase in wealth in the first part of the 20th century.” But society is now living on old oil fields, and “we’re spending more energy to find less and less energy,” he explains. “Politicians who say, ‘Drill, baby, drill’ have their heads up their asses. You don’t get more oil by drilling more. You just get less efficient returns. You only get more oil by drilling thoughtfully.”
The world’s fisheries mirror these energy declines, although cheap oil and subsidies have hidden the losses as industry compensates by moving from low-value catches like cod, once a staple for Caribbean slaves, to luxury items such as shrimp. Industry trawlers burn enough oil to support a ninety-mile line of Corvettes, bumper to bumper, with all engines revving. In some fisheries the edible protein hauled up amounts to less than 10 percent of the fuel energy burned. In addition, one-third of the world fishery catch—sardines, anchovies, and mackerel—is wasted as animal feed for industrial livestock or fish farms. Because it takes four to five pounds of small fish to make one pound of factory salmon, the EROI for factory fish hits 2 or lower. Daniel Pauly describes the fueling of fish farms with tons of small fish, which leaves less food for marine mammals as well as for people, as “the aquatic equivalent of robbing Peter to save Paul.” The oceans once made salmon for free. Now it takes five pounds of oil to fatten a single pound of caged salmon in a factory operating on the same principles as a Ford assembly line.
Industrial fishing has become such a backward, corrupt, and duplicitous enterprise that reform will not come from within, says Pauly. But the end of cheap oil may offer an opportunity for change. When the price of oil hit $150 in 2008, the over-energized trawler fleet contracted. High-cost oil may restore small-scale fisheries that employ fewer inanimate slaves and respect local waters. “In some countries sail boats are now being used again for fishing,” says Pauly. These reforms, combined with a substantial reduction in catches, the cancellation of $30 billion in subsidies, and the creation of extensive marine parks, argues Pauly, could prevent the collapse of the world’s fisheries. Pauly, whose ancestors were slaves imported to the United States, thinks it may be too late. However, he says, “you do the right thing whether you are successful or not. That’s how you give meaning to life. People in the depths of slavery fought against it because they had to. They could not do otherwise and they did not wait for emancipation. The fight against the machine is the challenge of our generation just as the fight against fascism was fifty years ago.”
Diminished catches of oil and fish ultimately mean diminished living. Cheap oil built giant cities, factory farms, extensive roads, big science, and even bigger government on returns greater than 20 EROI. Charles Hall estimates today that business as usual probably requires an EROI of at least 5, and even that quantity of surplus might not be sufficient to keep “all the infrastructure [needed] to train engineers, physicians and laborers.” He reckons that a sustainable EROI might be as high as 10. Any dirty fuel or renewable energy that provides smaller gains would translate into smaller government, markets, cities, and farms. With less surplus to energize a civilization dependent on billions of energy slaves, Hall suspects we might have to retire lots of mechanical help as well as reduce both labor productivity and wages. We might even have to reconsider how society distributes wealth.
An energy return of 10 is a significant number. Most hunter-gatherers lived on surpluses greater than that. But contrary to modern assumptions, many preindustrial societies enjoyed both high EROIs and stable living conditions. The !Kung bushmen of the Kalahari, for instance, fashioned lives that were neither nasty nor brutish. Just one !Kung adult could pick and hunt enough food to support four or five children and elders in a couple of hours. Securing food energy for the group rarely took more than two to three days of the week. The resourceful !Kung also enjoyed a much more varied diet than do the citizens of most industrial societies, including twenty-nine different fruits and berries, thirty different roots, and the drought-resistant mongongo nut. Gathering plants yielded higher returns than hunting animals and supplied 60 to 80 percent of the diet. During a sustained drought in the 1960s, the !Kung remained as resilient as ever while their agricultural neighbors starved in refugee camps. By spending a third of their time shopping in the bush, the !Kung enjoyed EROI surpluses of 12 to 1. With that heady profit they cared for the young, elderly, senile, blind, and sick and spent nearly half of the time playing, visiting relatives, and dancing. Steady leisure invariably followed steady work. Their energy returns were so profitable that U.S. anthropologist Marshall Sahlins calls hunter-gatherers “the original affluent society.”
Charles Hall doesn’t think many people will be able to keep bankers’ hours or dance like the !Kung with declining surpluses. On an island like Puerto Rico, where the ecologist has studied energy returns in the rain forest for decades, the importance of EROI rolls sharply into focus. Before the advent of oil, the island was a poor and hardworking village that sacrificed its forests for sugar exports. But after the introduction of oil and Operation Bootstrap, Puerto Rico became an industrial marvel. Thirty percent of its forests grew back as Puerto Ricans employed their new energy slaves to make pharmaceuticals and other goods. Now that the price of oil has reached $100 a barrel, and given that most of the island’s power comes from oil-fired generators, Hall fears the clock might run backwards.
Hall thinks that EROI also explains the damnable predicament of the United States. The world’s first petrostate, which once dazzled the planet with drilling energy returns of 1,000 to 1, now sputters along on returns of 10 to 1 or less. “I have seen the future, and it’s here,” says Hall. “Everywhere you turn in the United States you see economic constriction. About 46 of 50 states are broke. Our universities are broke. All the Tea Partiers are bent out of shape by the national debt. The country just can’t do a lot of the things that it used to do. We have had little or no increase in GDP and no increase in energy use for six years. And that’s not a coincidence.”
EROI also provides a reality check on renewable energy. Unlike fossil fuels, which nature stored in high-density pools and formations, the free energy flows of wind and solar must be collected and concentrated by people. That effort requires a lot of energy. Biofuels—fuel oils made from crops—illustrate the conundrum. Many scientists believe that the world might someday run on factory-made algae instead of petroleum. They argue that the microscopic plant grows fast and can potentially generate great volumes of lipids, or energy products. But to date, the production process yields EROI returns of significantly less than 1 and costs about $35 to make a gallon. The heavily subsidized ethanol industry also produces meager surpluses. Using oil-driven tractors, plows, cultivators, planters, combines, and irrigators to harvest corn for “gasohol” yields a slightly positive EROI. But when climate change, soil erosion, and the rising price of food are added to the equation, ethanol goes over the net energy cliff. (The Economist estimates that a large tankful of ethanol represents enough corn to feed one person for a year.)
In a critical review of surpluses generated by renewables more popular than biofuels, Hall found the same troubling story. None returned the same surpluses or gains as conventional fossil fuels. Industrial wind farms generate EROIs of approximately 18 to 1, nearly three times less than coal. (Bigger turbines appear to deliver bigger gains because they can capture more wind more efficiently.) But the wind blows less than one-third of the time on average. Tidal or wave energy may produce some surpluses, but the existing projects are too few to assess their true contribution. Tapping into the earth’s ambient heat via warm subterranean waters can yield returns of 5 to 1. Hydro power yields high returns, but most sources have already been dammed. The world’s most expensive energy, nuclear power, seems to have paltry returns of 5 to 8, though we lack good data. Capturing sunlight, often viewed as the utopian solution, comes with challenges too. Solar photovoltaics, which require energy-intensive manufacturing, must extend over large areas to net only a fraction of the sun’s energy. To date, photovoltaics offer energy returns ranging from 3 to 10.
Unlike Hall, Italian physicist Ugo Bardi believes that solar returns will increase with new and better technologies. Bardi argues that polycrystalline silicon offers an EROI of 15, while thin film cells might produce surpluses of 40. He also supports high-altitude kites, a novel technology that generates energy with yo-yo-like jerks to a generator on the ground. Scientists estimate that the kites might yield returns of 100. But tapping high-altitude winds could also affect rainfall patterns. Every energy surplus comes with some slavish and hidden cost.
Extreme hydrocarbons such as tar sands and shale oil perform worse than many renewables. They are the equivalent of the sardines, jellyfish, and slime at the bottom of the ocean food chain. Even the oil patch calls them “difficult” and “ugly” resources. The shale gas revolution makes a good but nuanced example. Now that the easy natural gas is gone, industry must drill deeper and then crack open giant shale formations as dense as concrete. The volume of methane released is so small that to make up the difference, companies must amass land bases the size of West Virginia. To blast open fractures in the rock, the industry pumps highly pressured volumes of sand, toxic chemicals, and millions of gallons of water a mile underground. In 2003, the industry used 2 million horsepower in its hydraulic fracturing operations. By 2011, it will need 11 million horsepower, or 8 gigawatts of energy. That’s the same amount of power generated by eight large U.S. nuclear power plants. The EROI for shale gas starts relatively high, at 80. But that number represents a 28-point drop compared to conventional gas a decade ago, and within another decade rapid depletion rates and rising energy costs will cause shale gas surpluses to fall catastrophically.
The energy returns for Canada’s bitumen—a tarry, overcooked crude mixed in sand and clay—are more abysmal. Once dug out of the ground, bitumen must be extensively upgraded with hydrogen and then put through a highly polluting refining process. The amount of energy needed to dig bitumen out of the ground, remove the sand and clay, and then convert the junk into synthetic crude ultimately delivers an EROI ranging from 3 to 5. That makes it a lowly competitor with biofuels. Deep deposits of bitumen require even more energy to access. Massive steam plants boil water with natural gas and then inject highly pressurized volumes of steam to melt the bitumen (about four barrels of steam for every barrel of bitumen produced). The inefficient process, which operates like a bottom trawler, typically heats up more rock than it does bitumen, delivering returns ranging from 3 to 1. Some bitumen steam projects actually deliver negative returns and perform as poorly as ethanol. Oil shale (kerogen), another poor and undercooked petroleum product, offers paltry net gains of 2 or 3. Its recovery process heats the ground up to 1,100 degrees Fahrenheit, with electrodes no less. Daniel Pauly compares mining unconventional hydrocarbons such as shale gas and bitumen to drag-netting bêches-de-mer: “Do you know what sea cucumbers eat? They lick the bottom of the ocean and they eat shit.” Canada opened a dragnet sea-cucumber fishery in Newfoundland after cod stocks collapsed due to overfishing in 2003. Thirty percent of the sea-cucumber catch is water and debris. Each year its EROI declines further.
The Global Energy Systems group at Sweden’s Uppsala University has added a new fish to the surplus debate. The group’s researchers note that the global oil boom started from nothing in the 1870s and then grew at 7 percent annually, doubling its output every ten years. Oil offered so much concentrated surplus that it served as a “dream given form” and “one of the most extreme events in human history.” Oil output even grew faster than nuclear power or hydroelectricity. By 1970, oil was delivering two thousand times more energy gains than it had in 1870. Given this unusual record, the Swedes don’t think any of the renewables, with their typically lower EROIs, could ever scale up like an oil boom. “The development and expansion of alternative energy sources has started too late to produce even a significant contribution over the next couple of decades,” the researchers write. They also pose a provocative question: “Should energy planning be based on the belief that new energy sources can grow faster than anything ever seen before in history?”
The implications of this analysis and Hall’s EROI work are disquieting. Neither unconventional fossil fuels (dirty oils) nor green renewables offer enough surpluses to feed the world’s hungry energy slaves, let alone their masters. Moreover, most scientific and government agencies no longer collect the detailed energy information necessary to make these calculations. Often they ignore the issue altogether. Charles Hall, who accuses energy regulators of criminal negligence, argues with Ajay Gupta that “there needs to be a concerted effort to make energy information more transparent to the people so we can better understand what we are doing and where we are going.” The situation, he writes, grows more extreme by the day. “The EROI of the fuels we depend on most are in decline; whereas the EROI for those fuels we hope to replace them with are lower than we have enjoyed in the past. This leads one to believe that the current rates of energy consumption per capita we are experiencing are in no way sustainable in the long run. At best, the renewable energies we look toward may only cushion this decline.”
Not long ago, Hall stood in the middle of Puerto Rico’s Luquillo Experimental Forest to talk about the importance of energy costs and gains for the Discovery Channel. What works in a rain forest, he told viewers, also works for civilized society and for empires based on oil. “I think it’s very simple,” he said. “Just as the forest cannot use more energy than is available by photosynthesis, human civilization cannot use more energy than what’s available from the sun or from our temporary joy ride on fossil fuels.”