Read The World in 2050: Four Forces Shaping Civilization's Northern Future Online
Authors: Laurence C. Smith
Tags: #Science
There is also the “liquid-fuels” problem: Not all transport can be electrified. There is no foreseeable battery on the horizon that will power airplanes, helicopters, freight ships, long-haul trucks, and emergency generators. These all require the power, extended range, or portability offered by liquid fuels. For these forms of transport, gasoline, diesel, ethanol, biodiesel, liquefied natural gas, or coal-derived syngas will be necessary for decades. However, electrification of the passenger vehicle fleet will help ensure adequate supplies of these liquid fuels. And perhaps one day, our descendants will be grateful that we left them enough oil to still make plastic affordable.
So peering forward to 2050, we find a world more heavily electrified than today, and an assortment of strange new liquid fuels. Where will these new energy sources come from? Will clean renewable electricity replace hydrocarbon-burning power plants? And what about hydrogen power, the fuel of space ships, sci-fi movies, and Arnold Schwarzenegger’s specially designed Humvee?
Let’s start with the last. First, it is important to remember hydrogen is not truly an energy
source
but, like electricity, an energy
carrier
. Pure hydrogen makes a wonderful fuel but isn’t just lying around for the taking.
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Instead, just like making electricity, it must be generated using energy from some other source.
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A feedstock material is also needed from which to strip hydrogen atoms. The most common feedstocks in use today are natural gas or water, but others, like coal or biomass, are also feasible sources of hydrogen. Energy is used to crack the hydrogen from the feedstock—for example through electrolysis of water
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—yielding a portable fuel in gas or liquid form. One kilogram is packed with about the same energy as a gallon of gasoline.
But unlike gasoline, the hydrogen is not then burned in a combustion engine. It is instead converted to electricity on-site, by feeding it into a fuel cell. Fuel cells essentially reverse the hydrolysis reaction, combining hydrogen with oxygen to create electricity and water. The newly made electricity is then used to power the car, appliance, furnace, or whatever, with the water by-product either released as vapor or recycled. Like plug-in electrics, fuel-cell cars release no tailpipe pollution or greenhouse gases (besides water vapor
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). However, they
are
released at the hydrogen plant, unless fossil fuels or biomass can be avoided as sources of energy or feedstocks. In principle, solar, wind, or hydroelectric power could be used to split hydrogen from a water feedstock, making the entire process quite pollution-free from beginning to end.
Sounds wonderful, and many energy experts and futurists believe that one day we will have a full-blown hydrogen economy. The ultimate dream is to use solar energy to split hydrogen from seawater, thus providing the world with an infinite supply of clean hydrogen fuel—and even some freshwater as a bonus—with no air pollution or greenhouse gases. But nothing like that will be in place by 2050.
Years of research are needed to resolve a rat’s nest of challenges concealed within the previous two paragraphs, with major technology advances and cost reductions necessary in all areas.
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Basic research in hydrogen manufacture, transport, and fuel cells is still lacking. The cost of making a fuel-cell vehicle is extremely high. A completely new physical infrastructure is required, including manufacturing plants, pipelines, distribution and bottling centers, and filling stations. Hydrogen is explosive, so there are many safety issues to be resolved, like how to safely pack enough of it into a vehicle to drive three hundred miles, comparable to vehicles today. One way is to use highly pressurized hydrogen, but the collision safety of ten-thousand-psi tanks remains unproven. Early hydrogen supplies are all but certain to be made from fossil fuels, and thus will help little with reducing carbon emissions.
In light of these challenges, most experts agree that a hydrogen economy lies at least thirty to forty years in the future, at which point hydrogen fuel-cell cars might possibly be the new “next-generation” technology that plug-in hybrids are today. Under the conservative ground rules of our thought experiment, we will assume the world will not convert to a hydrogen economy by the year 2050.
Running on Moonshine and Wood
Unlike hydrogen, biofuels offer a quicker solution to the liquid-fuels problem. Like gasoline, they are refined hydrocarbons that are burned in an internal combustion engine. They use the same filling stations and, with only slight modifications, the same car and truck engines of today.
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The only real difference between biofuels and current fuels is that they are made from contemporary organic matter rather than ancient organic matter, and are somewhat cleaner. They emit similar levels of carbon dioxide from the tailpipe as gasoline or diesel, but fewer sulfur oxides and particulates. In principle, when biofuel crops grow back they draw down a comparable amount of new carbon from the atmosphere, thus offsetting their emission of greenhouse gas, but this does not take into account the added emissions of growing, harvesting, and transporting the crop. The biggest appeal of biofuels, therefore, is that they offer a domestic or alternative liquid-fuel source to oil, and potentially less greenhouse gas emission, depending on how efficiently the biofuel can be produced.
The most common biofuel today is ethanol made from corn (in the United States), sugarcane (Brazil), and sugar beets (European Union). Making ethanol is essentially the ancient art of fermenting sugars to make alcoholic drinks, meaning that corn-based car fuel is very similar to moonshine. It is commonly mixed with gasoline, and in Brazil, cars run on flex-fuel mixtures containing up to 100% ethanol. Ethanol has higher octane than gasoline and for this reason was used in early racing cars. In fact, when cars were first being developed about a century ago, their makers strongly considered fueling them with ethanol.
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The world’s two largest ethanol producers are the United States and Brazil, together producing more than ten billion gallons per year. That may sound like a lot, but it’s less than 1% of the liquid-fuels market. The good news is that Brazil is becoming quite expert at making sugarcane ethanol. Production is rising rapidly and is expected to double by 2015.
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Sugarcane plantations are expanding and, contrary to popular belief, represent little deforestation threat to Amazon rain forests because they are found mostly in the south and east of Brazil.
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Improved agricultural practices have more than doubled the ethanol yield per unit area, and new genetic methods called marker-assisted breeding suggest further increases of up to 30% in the future. The price Brazilians pay for ethanol has steadily fallen for the past twenty-five years even as the price paid for gasoline has gone up.
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In 2008, for the first time in history, Brazilians bought more ethanol than gasoline.
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The United States is also ramping up ethanol production. The 2007 Energy Independence and Security Act calls for a tripling of U.S. corn-based ethanol production by 2022, a goal reaffirmed by the Obama administration in 2010. Ethanol also comprises a large part of the U.S. Department of Energy’s official goal to replace 30% of gasoline consumption with biofuels by 2030. The European Union hopes to derive a quarter of its transport fuels from biofuels by the same year.
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Unfortunately, there are tremendous differences in production efficiency among the different plant crops used to make ethanol. Sugarcane is a high-value feedstock, yielding up to eight to ten times the amount of fossil-fuel energy needed to grow, harvest, and refine sugarcane into ethanol. Corn-based ethanol, in contrast, is terribly inefficient, usually requiring as much or more fossil fuel in its manufacture as is delivered by the final product. Therefore the greenhouse gas benefit of corn ethanol over oil is negligible.
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While often pitched otherwise, American subsidies for it are for objectives other than greenhouse gas reduction. For that goal, a far smarter biofuel investment would be production of sugarcane ethanol in the Caribbean, a potential “Middle East” for ethanol export to the United States.
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Another problem is that current technology requires ethanol to be made from simple sugars and starches, putting biofuel crops in direct competition with food crops. The U.S. corn ethanol program was widely blamed in 2007 for a worldwide rise in food prices, because it subsidized farmers to plant fields with corn for fuel rather than with wheat and soybeans for food.
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This notion that biofuels threaten global food supply reared up again in 2008 in response to a series of food riots in Haiti.
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While this fear is probably overblown—the share of arable land currently used for biofuel production is only a few percent, and geographic models indicate adequate land does exist for the coexistence of energy and food crops
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—it is nonetheless disturbing to imagine, in a 2050 world with half again more people than today, converting large swaths of prime farmland to feed cars instead of people.
An attractive alternative would be making ethanol from cellulose, extracted from low-value waste and woody material. Indeed, to make sense any large-scale conversion to biofuels must include cellulosic technology.
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Cellulose is found in waste products like sawdust and cornstalks, or in grasses and woody shrubs that grow on marginal land not suitable for food crops. It is also the only way to achieve large greenhouse gas reduction through biofuels: Because cellulose requires little or no mechanical cultivation, fertilizers, or pesticides, the amount of fossil fuel needed to produce it is greatly diminished.
At the moment, we do not yet have the technology to produce cellulosic ethanol at sufficiently low price and large scale to penetrate the liquid-fuels market. Woody material contains lignin, a tough polymer that surrounds the cellulose to strengthen and protect the plant. Lignin prevents enzymes from reaching the cellulose to break it down to sugars that can then be converted to ethanol. Current methods for doing this require strong acids or high temperatures, making them uneconomic. But cows and termites, through a symbiotic relationship with gut bacteria, have no problem breaking down cellulose, and promising research is under way to discover how we can too.
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Another potential source of liquid biofuels is algae (e.g., algenol), which can be grown in non-agricultural, non-forest places like deserts, potentially even from wastewater and seawater.
Whether from increased competition with food crops, or the harvesting of brush and wood for cellulose, a downside of all biofuels is a pressure to expand cultivation, putting even more pressure on natural habitats. Because they consume so much land area, biofuels have the largest “ecological footprint” of any energy source including fossil fuels.
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Another challenge is purely logistical. Most plant biomass is dispersed over the landscape. How will we secure enough of it, and deliver it to plants at a reasonable cost, without also burning large amounts of fuel in the process? In an echo of hydrogen, this lack of broad-scale processing infrastructure thus remains an open challenge to major production of liquid biofuels.
Of the nonfossil fuel sources of energy, biomass is the world’s most important source today, accounting for around 9%-10% of total primary energy consumption. Most of this comes from burning wood and dung for heating and cooking in developing countries. While less than 1% of the world’s electricity production comes from biomass, its role is expected to grow across all energy sectors in the next forty years, with total biomass consumption rising 50%-300% by the year 2050.
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Sugarcane ethanol is already a success, and most experts feel that an economically viable cellulosic technology will be found. If the described challenges to agriculture, land management, and infrastructure can be met, biofuels could possibly supply up to a quarter of all liquid transport fuels by 2050.
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But this is no small task: With world population growing another 50% over the same period, it means tripling our current agricultural productivity. Total bioenergy use in 2050 would have to approach the level of world oil consumption today.
Was Jack Lemmon’s Oscar a Setback for the United States?
On March 16, 1979, the movie thriller
The China Syndrome
opened, starring Jack Lemmon, Michael Douglas, and Jane Fonda. It was about a nuclear accident, compounded by a series of human blunders and criminal acts, at a fictional nuclear power plant in California. By sheer coincidence, just twelve days later a nuclear reactor core was seriously damaged at the Three Mile Island power plant near Harrisburg, Pennsylvania. The level of radioactivity leaked into the environment was too low to harm anyone, but the accident’s timing was uncanny. The real accident, although quickly contained, brought immediate attention to the film and it became a box-office smash.
Jack Lemmon won an Academy Award for his performance as the distraught plant manager who barricades himself inside the control room to prevent a criminal cover-up by the plant’s owners. I won’t spoil the ending, but the story remains gripping to this day.
The China Syndrome
horrified an audience of millions and, together with the accident at Three Mile Island, helped to turn the court of U.S. public opinion against nuclear energy. The last year that a construction permit for a new nuclear power plant was issued in the United States was 1979.
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Then, a second, far more deadly catastrophe occurred. On April 26, 1986, nuclear reactor unit No. 4 exploded at the Chernobyl power plant in Ukraine, then part of the Soviet Union. The blast and consequent fire that burned for days released a radioactive cloud detected across much of Europe, with the fallout concentrated in Belarus, Ukraine, and Russia. Two people were killed in the plant explosion, and twenty-eight emergency workers died from acute radiation poisoning. About five million people were exposed to some level of radiation.
Soviet officials initially downplayed the accident. It took eighteen days for then-general secretary Mikhail Gorbachev to acknowledge the disaster on Soviet television, but he had already mobilized a massive response. Soviet helicopters dropped more than five thousand tons of sand, clay, lead, and other materials on the reactor’s burning core to smother the flames. Approximately 50,000 residents were evacuated from the nearby town of Pripyat, still abandoned today with many personal belongings lying where they were left. Some 116,000 people were relocated in 1986, followed by a further 220,000 in subsequent years. Approximately 350,000 emergency workers came to Chernobyl in 1986-87, and ultimately 600,000 were involved with the containment effort. Today, a thirty-kilometer “Exclusion Zone” surrounds the Chernobyl disaster site, and Ukraine’s government expends about 5% of its budget annually on costs related to its aftermath.
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Although claims of tens or even hundreds of thousands of deaths are exaggerated—by conservative estimates perhaps 8,000 people suffered cancer as a result of Chernobyl
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—and the failures leading to the explosion are unlikely to be repeated, it was an epic catastrophe from which the Soviet Union and nuclear industry never fully recovered. In the United States and many other countries, what lingering support for nuclear power had remained after Three Mile Island was largely buried alongside the victims of Chernobyl.
Today, that situation appears about to change. In late 2008, the U.S. company Northrop Grumman and the French company Areva, the world’s largest builder of nuclear reactors, announced a $360 million plan to build major components for seven proposed U.S. reactors. Twenty-one companies were seeking permission to build thirty-four new nuclear power plants across the United States, from New York to Texas. By 2009 the French firm EDF Group was planning to build eleven new reactors in Britain, the United States, China, and France, and contemplating several more in Italy and the United Arab Emirates. In 2010 U.S. president Barack Obama pledged more than $8.3 billion in conditional loans to build the first nuclear reactor on U.S. soil in over three decades, and for his 2011 budget sought to triple loan guarantees (to $54.5 billion) supporting six to nine more. In a
Wall Street Journal
Op-Ed, U.S. secretary of energy Steven Chu called for building “small modular reactors,” less than one-third the size of previous nuclear plants, made in factories and transported to sites by truck or rail. And for the first time nearly two-thirds of Americans were in favor of nuclear power, the highest level of support since Gallup began polling on the issue in 1994.
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One reason for all the renewed interest is that nuclear fission is one of only two forms of carbon-free energy already contributing a significant fraction of the world’s power supply.
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Notwithstanding the threatening appearance of billowing white plumes streaming from concrete nuclear towers, they emit no greenhouse gases directly,
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thus winning the support of a surprising number of climate-change activists. To date, nuclear reactors have been tapped mainly to produce electricity, but they also have potential uses for seawater desalinization, district heating, and making hydrogen fuel.
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Nuclear power plants are very costly and take years to build, but once established they can provide electricity at prices comparable to burning fossil fuel. In some countries like Japan, nuclear power is actually cheaper than fossil-fuel power.
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Nuclear advocates point to France, which gets about 80% of its electricity from nuclear plants with no accidents so far. Belgium, Sweden, and Japan also obtain large amounts of electricity from nuclear reactors, so far without major mishap.
Public health remains the single greatest concern with nuclear energy. Although great strides have been made to increase reactor safety,
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accidents and terrorism remain legitimate threats. Of grave concern is the disposal of radioactive waste, which must be safely interred for tens of thousands of years. The most feasible way to do this is probably subterranean burial in a geologically secure formation. But certifying anything as “geologically secure” for a hundred thousand years is exceedingly difficult. After more than two decades of research and $8 billion spent, the U.S. government recently killed plans to tunnel a long-term nuclear waste repository into Yucca Mountain, a volcanic formation in Nevada. Even in the middle of desert, there was simply too much evidence of fluctuating water tables, earthquakes, and potential volcanic activity to declare the site “safe” for a hundred thousand years.
Finally, there is the issue of fuel supply. Estimated R/P life-index estimates for conventional uranium are under a hundred years, with most closer to fifty years. Therefore, over the long run a shift to nuclear power will require the reprocessing of spent uranium fuel rods from conventional “once-through” nuclear reactors so as to recycle usable fissile material. But spent-fuel reprocessing yields high-grade plutonium, even small amounts of which are the principal barrier to acquiring a nuclear bomb. Therefore, any expansion in nuclear power that involves spent-fuel reprocessing or breeder reactors elevates the threat of proliferating nuclear weapons and creates attractive targets for terrorism.
Nuclear power generates about 15% of the world’s electricity today. In a recent analysis of the industry’s future, the Massachusetts Institute of Technology concluded that if aggressive steps are taken to deal with the issues of waste disposal and security, it is feasible to more than triple the world’s current capacity to 1,000-1,500 conventional “once-through” nuclear reactors, up from the equivalent of 366 such reactors today.
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Enough natural uranium is available to support this to at least midcentury or so. Depending on the choices we make,
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our global nuclear power capacity is projected to either stagnate or grow fivefold, producing as little as 8% to as much as 38% of the world’s electricity by the year 2050.