"Tonight I want to have an unpleasant talk with you," a somber President Jimmy Carter said gravely into a television camera on an April night in 1977.
A series of oil embargoes and OPEC price hikes had hit the nation hard. Gasoline prices had tripled. Auto-dependent Americans had sometimes waited hours in line to buy the gasoline needed to get to work. The president, in an iconic fireside chat – in a beige cardigan – two months earlier had congenially urged Americans to turn thermostats down to 65 degrees F. by day, 55 by night.
But on this night, he ratcheted up his tone: Warning of an imminent "national catastrophe" and scolding Americans for selfish wastefulness, the president declared it time for Americans to curb consumption of oil, which he said had doubled in the 1950s and again in the '60s – time to end their dependence on imports.
"This difficult effort will be the moral equivalent of war," he said.
Mr. Carter created the Department of Energy. He called for energy conservation and increased production of coal and solar power. He installed solar panels on the White House.
But his vision – to push America and the world into a new energy era as significant as the shift from wood to coal that fueled the Industrial Revolution – never materialized.
Gasoline prices plummeted in the 1980s, removing the incentive to end oil imports. Driving returned to precrisis levels. Carter's successor, Ronald Reagan, withdrew funding for renewable energies. And the White House solar panels were torn down.
While experts in the late 1970s believed that America would derive 30 to 50 percent of its power from renewable sources by 2005, it didn't happen. Renewables, other than hydroelectric, now make up about 4 percent of the energy that Americans consume.
As Americans come to grips with current energy problems – this time with climate change as the looming threat – it's also a good time for perspective. Over the past 200 years, the world has seen about a dozen major transitions in how it obtains or uses energy. Looking back at those transitions provides some surprising hints about how the next 50 years will unfold. Our energy future will look very different from what most people imagine.
Energy revolutions have usually been slow, starchy, conservative affairs, not overnight explosions; and the next one promises to be, too – never before has humanity replaced 15 trillion watts of worldwide energy production. Our success in making it happen quickly enough to stave off climate change will depend every bit as much on strategic use of fossil fuels now as it does on flashy new technologies in the future.
The steep growth in technology, population, and wealth over the past 150 years was propelled by fossil fuels – and this could probably have happened only once in history. The fuels that were combusted over a matter of decades took much of Earth's lifetime to accumulate. The Huqf oil formation in southern Oman is up to 700 million years old; it coalesced from plankton that settled on the ocean floor before the first primitive swimming, burrowing animals appeared on Earth. These fuels are being consumed 100,000 times faster than they formed.
On the upside, we humans are getting more out of our fuels. Due to increasingly efficient engines, ovens, and generators, we now derive four times as much useful heat, electricity, and mechanical thrust from every ounce of fuel that we burn compared with the late 1800s. But our demand has exploded. We now burn 20 times as much fossil fuel as we did in the late 1800s: the work that fossil fuels do for us has increased 80-fold in a little more than a century.
Replacing that energy is doable. But coming up with a realistic approach will require taking into account some facts that usually go unsaid.
RENEWABLES HAVE VICES, TOO
To feel the constant whip of winds across the Great Plains, or to bake in the endless sunlight of the American Southwest, is to imagine that these renewable energy sources are limitless.
But they aren't, says Vaclav Smil, an energy scientist at the University of Manitoba. He points to his calculations that harvesting all of the accessible power from ocean currents, tides, and geothermal heat worldwide would only replace about 2 percent of the energy that we derive from fossil fuels. Likewise, stopping up every economically harnessable river on Earth with a hydroelectric dam – an unlikely scenario – would still replace only 10 percent of our fossil fuel use. And wind – if we harnessed all of the power that can be realistically recovered at a height of 250 feet over the Earth's surface – might replace 10 or 20 or 30 percent of our fossil fuel use.
Of all of the renewable energies, says Mr. Smil, only solar can do the job single-handedly. Capture just 1/1000th of the sunlight that reaches our planet's surface and we could replace our entire use of fossil fuels.
Even if solar and wind have the greatest potential, we'll need a diverse mix of renewables. Iceland has poor sunlight, but could do well with geothermal energy. Norway and New Zealand have done well with hydroelectric power. And in rural Asia and Africa, low-tech thermal reactors could convert agricultural wastes such as wheat chaff into gaseous fuels.
These measures might relegate oil spills and mountaintop removal to memory. But they'll create new challenges of their own.
GET READY FOR 'ENERGY SPRAWL'
If smokestacks defined the landscape of the Industrial Revolution, then the monstrous spinning wind turbines and sprawling fields of solar collectors will become landmarks of the new energy age.
It goes like this: All of the oil wells, strip mines, refineries, and pipelines needed to extract fossil fuels worldwide cover an area the size of Belgium, says Smil. That sounds big until you consider the alternative.
Electricity-producing solar cells provide about a tenth as much energy per acre as fossil fuel extraction does. Wind farms produce 1/30th to 1/100th the energy per acre. And biofuels like corn ethanol fare even worse: from 1/300th to 1/1000th the energy per acre.
Even if you use the entire US corn crop for ethanol, declares Smil, "you would supply 13 percent of [US] gasoline."
A study published last year in the journal PLoS One forecasts that by 2030, the shift toward renewables will push energy production onto 80,000 square miles more land than it currently occupies in the United States – an area equal to Nebraska.
Energy sprawl will create pressure to place wind farms on land already used for pasturing or farming crops. It will prompt efforts to cover rooftops with solar collectors even in cities with marginal sunlight. And it will mean spreading energy production across multiple sources to minimize the impact on any one habitat – even if some sources, like geothermal or tides, have less inherent potential.
NO OVERNIGHT BOOM
Unlike the gold rush that spawned an overnight boom, America's first commercial oil well caused hardly a ripple. Sunk in 1859 in Titusville, Pa., it cranked on for years before oil became a big player in American energy.
Adopting renewable energies will also take more time than people realize. In 2008 Al Gore announced his Repower America plan to transition the US to renewable fuels within 10 years. Google and T. Boone Pickens proposed similar quick-action plans.
Smil doesn't see much realism here. He has studied a dozen energy transitions that occurred since 1800, including those from steam engines to gasoline and diesel engines, from wood and charcoal to coal, and the adoption of oil and natural gas.
"It's a very long process," he says. "It takes decades – 30, 40, or 50 years."
Consider oil: It was cleaner-burning than coal, contained 60 percent more energy per ounce, and offered unmatched precision for controlling engines.
But from that first commercial oil well in 1859, oil took 45 years to gain just 5 percent market share against coal, and 40 years more to gain a third of the market. That snail-like pace stemmed from the need to build refineries, railroads, pipelines, and eventually filling stations – plus a fleet of autos and ships to use the fuel. Meanwhile, the US built coal-powered Liberty-class transport ships for Britain early in World War II – even though these steam engines were half as efficient as diesel engines.
Smil believes that the transition to renewables could take even longer. It will mean replacing a fossil fuel infrastructure that took 150 years to build and is valued at $15 trillion worldwide and $2 trillion in the US. That would be heavy political lifting, considering government debt and the uproar sparked by the $787 billion stimulus bill in 2009.
"It's simply a [matter of] scale," says Smil. "We're talking about massive new investments."
If there's any ray of hope here, it could be the one that travels 186,000 miles per second – sunlight. Even though silicon solar cells still supply less than half a percent of the world's electricity – 40 years after their invention – some people now see the growth curve bending upward.
"2008 was a historic year," points out Daniel Kammen, an energy physicist at the University of California at Berkeley, and visiting scientist at the World Bank in Washington, D.C. "That was the first year that global production of high-purity silicon for the solar industry was greater than for the computer [chip] industry."
Today's rate of solar-cell manufacturing allows the added energy production of only the equivalent of about 10 nuclear power plants each year. To put that in perspective: The US would need to build one nuclear plant per week for almost 10 years to replace the power it gets from fossil fuels.
But the global solar photovoltaic industry is growing on average 50 percent per year – driven by innovations and policies in some countries that encourage their use. And another type of solar – sunlight concentrating – which uses mirrors to focus sunlight, heat gases, and turn an engine to generate electricity, is also blossoming.
Several weeks ago, the first large, sunlight-focusing solar plant received approval for construction on federal land – a 709-megawatt installation planned by Tessera Solar for 10 square miles of desert in California's Imperial Valley. The project still faces hurdles. Existing transmission lines can only transport half the electricity that it will generate. In fact, many of the US's 170,000 miles of high-tension lines will need to be rerouted to connect solar and wind plants to the grid – a $150 billion expense, says Smil.
If you're a homeowner wanting to put solar on your roof, the upfront cost of installing those solar cells presents another challenge. Averaging the installation costs over years and adding the financial incentives offered in some areas, the cost of home-generated solar electricity starts at 15 to 20 cents per kilowatt-hour – double the US average of 9 cents for grid electricity from fossil fuels.
Even so, industry observers expect that solar power produced in power plants and on rooftops will together generate 10 to 20 percent of American electricity by 2030. "We can accelerate that or slow it down," says Mr. Kammen; it will depend on government policies. "Reaching for the Sun" explains how group buying can drive down solar costs.)
Solar does suffer one major drawback – and this also affects wind power, which still produces twice as much electricity worldwide as solar and is steadily growing. Each source relies on a natural condition – the presence of sun or wind, respectively – to generate electricity. Ways must be found to store that energy – say, by pumping water uphill or pressurizing air in caverns – so it can be used at other times to produce electricity.
Until that happens, solar will be relegated to providing power during daytime, when electricity usage is highest. Another source will have to provide base-load electricity, which is consumed day and night – and this almost certainly means fossil fuels.
CONSERVATION HARDLY TAPPED
There are plenty of ways to burn less fuel. Imagine that you're in the kitchen doing dishes one afternoon. A red light flashes, and a digital display on the wall tells you that your power usage has spiked. Your power bill currently sits at $28.98 – just six days into the month.
You might just do something about it. You might turn off the computer that's sitting idle. That's 200 watts. You might tell your kid to shut the window – there's another 50.
The fact is that person for person, Americans consume up to twice as much energy as Western Europeans; much is wasted on inefficiencies that have little impact on lifestyle.
Getting people to conserve energy will require giving them more information. That could mean placing the power meter prominently in the kitchen – not hiding it behind a poisonous oleander bush in the backyard where a stranger glances at it once a month.
That meter would tick away dollars and cents as they're spent, and sound a little alarm when peak electricity prices kick in. You might compare it to the task that we face in making another opaque market more transparent – the health-care market – so that people can see the cost of their decisions and take steps to manage them. Studies of direct feedback have produced 5 to 15 percent reductions in electricity use – and this is just the beginning.
Most of the biggest energy savings come from replacing old appliances with more efficient ones. An analysis published last November in the journal Proceedings of the National Academy of Sciences suggests that low-tech actions such as weatherizing homes and installing more-efficient water heaters could reduce household carbon emissions by 20 percent within 10 years.
Those projections aren't pie in the sky, either: They account for the fact that many people ignore incentive programs. The key will be rolling out programs to make conservation easy for the average person, says Paul Stern, the behavioral scientist at the National Research Council in Washington, D.C., who co-wrote the study. "If you're going to insulate your house, you have to find contractors you trust and you have to evaluate them against each other," says Mr. Stern. "If you're going to be an informed consumer, it's not easy. A lot of people have got more pressing things in their lives."
In that sense, the greenest technology that we could devise in the foreseeable future might just be well-designed programs that take the guesswork out of home and appliance upgrades.
HURRYING ACROSS THE BRIDGE
It will also be necessary to consider all of those smokestacks gushing coal exhaust into the sky. Americans may want to kick their coal habit soonest – even before they're off the other fossil fuels.
Compared with oil and natural gas, coal releases up to twice as much carbon per unit of energy produced. And although coal tends to be seen as old-fashioned fuel – the stuff that powered Charles Dickens's London – its use continues to grow.
The US still derives 50 percent of its electricity from coal, and China doubled its use of coal-fired power plants from 2000 to 2007, building roughly one new plant per week, according to estimates provided in recent reports by the Massachusetts Institute of Technology and the US Department of Energy.
The good news is that many coal-fired power plants could be retrofitted to burn natural gas. It involves removing heavy machinery that pulverizes coal into dust, and replacing steam turbines with massive gas turbines. It is no small expense – but utilities sometimes do this anyway for purely profit motives when gas prices are low.
Swapping coal for gas on a large scale could cut carbon emissions by hundreds of millions of tons as the world moves toward renewables.
"Natural gas is the logical bridge [fuel]," says Joseph Pratt, an energy historian at the University of Houston. "We might want to hurry across that bridge," he adds. "Even hurrying is two generations, I'm afraid."
Hurrying will require compromises.
Electricity produced from wind or solar can power many homes and factories as is, but the world's automobiles, cargo ships, and airplanes rely on liquid fuels – gasoline, kerosene, and diesel. Ramping up mass transit and building a fleet of electric ships and autos will take decades.
AIRLINES STUCK IN THE KEROSENE AGE
But air transport presents the biggest problem. "The gas turbines in long-distance flying, that's the only way to go," says Smil. "There is no [replacement] on the horizon." Those same massive, kerosene-powered turbines propel every Airbus, 747, and cargo jet in the world. Even if engineers could devise aircraft that use electricity to travel at the speed of jets (and nothing like that exists – electric dirigibles notwithstanding), there's no way to carry the energy needed to propel such an airplane: The best batteries weigh 50 times more than jet fuel per unit of energy stored.
It means that the only renewable option for transportation, especially air transport, will be biofuels produced from corn, soy, sugar cane, and other sources – this, despite the fact that they demand enormous amounts of land and water, and may well encourage deforestation.
Continuing to rely on fossil fuels beyond a certain point will have consequences. Since the start of the Industrial Revolution, carbon dioxide in the atmosphere has risen from 280 parts per million to 380 p.p.m. Many climatologists now believe that letting it rise to a "red line" of 450 p.p.m. (which could happen by 2080) would trigger catastrophic changes, such as the melting of the Greenland and West Antarctic ice sheets. Steven Davis, a climatologist at the Carnegie Institution for Science in Palo Alto, Calif., has looked at how to avoid crossing that critical line.
In a paper published in the Sept. 10 journal Science, Mr. Davis reached a surprising conclusion. He calculated that if every Humvee, power plant, and other fossil fuel-burning device on Earth was used until it wore out – and then replaced with a carbon-neutral device – carbon dioxide would peak just below the red line.
In a way it's good news.
"It may suffice to get existing coal-burning power plants to commit to scheduled shutdown dates, and not to spend political capital on shutting them down early," says Davis.
If that plan were followed, typical shutdown dates for power plants might be 40 years away, creating the illusion of time to spare, says Davis. But his scenario, Davis says, "is still pretty radical" because every day, new automobiles and airplanes continue to roll off assembly lines around the world.
IS POLITICAL WILL RENEWABLE?
Solar panels are headed back to the White House roof. It's an odd echo of the Jimmy Carter days – the kind of news that might send your average conspiracy theorist scrambling to check whether Nostradamus predicted it. In fact, today's US energy scene bears plenty of odd similarities to that of the 1970s.
Then, as in 2008, gasoline prices spiked and the public directed its anger at energy companies' profits. Then, as now, competing interests called for solving the problem with more government regulation (to promote renewables) – and less regulation (to increase oil and gas production). Then as now, the public and many members of Congress bristled at the idea of pricing energy according to its real cost. And then, as now, a Democratic president ordered that solar panels be installed on the White House. (President Obama announced last month that the panels will be installed by the spring.)
In 2009 the crisis deflated once again, as outside forces (this time a recession) caused gasoline prices to fall. Falling prices drained some of the momentum from renewable energies. Some projects, like the Pickens offshore wind farm in Texas, got put on the back burner.
In a way, nothing has changed.
But the 1970s also spawned successes. France installed cookie-cutter nuclear power plants around the country; it now derives 75 percent of its electricity from the splitting of uranium atoms. Brazil achieved self-sufficiency for liquid fuels; it ramped up production of ethanol from sugar cane and compelled filling stations to stock the fuel.
"The countries that made more progress than [the US] chose a path, always controversial, and stayed with it," says Mr. Pratt.
You might say the US path has been gadgets: What if, for example, you could store electricity in paper? What if you could fold that paper up like origami and stuff it inside your iPhone, Segway, or Tesla automobile? For the first time ever, batteries would no longer be the albatross around the neck of every electronic device on the planet.
Today's outlook is in some ways brighter than it was 30 years ago. Technology has pushed the price of solar power lower than it was in 1980 – making it more viable. Wind turbines have increased eightfold in size, increasing the energy that they harvest per acre of land. Dozens of incipient technologies that didn't exist in 1980 now wait in the wings: nanocomposite paper that could provide batteries 1/10th as light as lithium ones; lightweight carbon fiber auto bodies that could double fuel-efficiency; and schemes for trickling electricity through compost to produce hydrogen gas.
Most of these technologies will fizzle; a handful will succeed and help propel the energy sector decades from now. Fast-tracking these technologies to the market (as well as wind, solar, geothermal, and other renewables) will depend on subsidies – whether they come in the direct form of rebates and tax breaks, or the indirect form of pricing energy according to carbon output. It will require getting past the popular narrative that our energy market has, until now, been laissez-faire.
"Oil never survived on the market independent of government support," points out Martin Melosi, an energy historian and colleague of Pratt's at the University of Houston. "Tax breaks, favorable land deals, limited antipollution legislation – all of those things favored oil production."
Incentives for renewable energy will need to be based more on rational science than on the Iowa Caucuses. A study published last year by the Environmental Law Institute suggests that from 2002 to 2008, 58 percent of US subsidies for renewable energy went to corn ethanol alone; many of those dollars would be better spent on technologies with greater potential.
"There's a lot of attention being paid to turkeys that are running around posing as solutions," says Davis. "We really need to consider things that are going to take 10, 20, 30 percent out of the problem."
Even as we conserve energy, we'll continue finding new ways to use more of it – just as we have for the past 2,000 years. Computers may now consume up to 100 times more energy than they did in 1970; worldwide energy consumption by data centers like the ones run by Google is doubling every five years as they become more intertwined with the basic sustenance of modern civilization. No one can say what the next energy-intensive industry will be. Or how quickly population will rise. Or how soon the billions of souls in Asia, Africa, and South America will adopt energy-intensive, Western lifestyles.
One thing is certain – all energy on Earth derives from a deceptively small number of sources: sunlight that drives winds, ocean currents, and the photosynthesis that leads to fossil fuels; radioactive elements that heat the Earth's interior and fuel nuclear power; and the inertia of celestial orbits that drives tides.
Some of that energy is easy to harvest – such as oil, the photosynthesis of millions of years condensed into a viscous liquid. Some of it will be more difficult – such as winds circling Antarctica hundreds of miles offshore.
We'll inevitably find ways to harvest more energy as our needs increase. But in a way, energy will always be scarce.