Register for an account


Enter your name and email address below.

Your email address is used to log in and will not be shared or sold. Read our privacy policy.


Website access code

Enter your access code into the form field below.

If you are a Zinio, Nook, Kindle, Apple, or Google Play subscriber, you can enter your website access code to gain subscriber access. Your website access code is located in the upper right corner of the Table of Contents page of your digital edition.


4 Bold Ideas to Make America’s Energy Supply 
Safer, Cleaner & 
Virtually Inexhaustible

A group of experts charts out a path for navigating through humanity's painful energy transition.


Sign up for our email newsletter for the latest science news

Perhaps it is time to retire the term “energy crisis.” People have been talking about one crisis or another since at least the early 1970s, for so long that the term has nearly lost its meaning. At any rate, we are not about to run out of energy: We have enough fossil fuels on the planet to power civilization for another half century or more. It is more honest to say that we are in the midst of an energy transition, a wrenching change in the kinds of energy we use and the ways we produce them. If we continue to rely on coal to keep the lights burning and gasoline to keep our cars running, we are bound to pay a heavy price. Imported oil accounts for 42 percent of our trade imbalance. Fossil fuels collectively produce 95 percent of the carbon emissions that are heating the planet. And the need for reliable sources of energy becomes more evident with every geopolitical tremor.

Greenhouse-gas emissions produced by each economic sector in the United States. Source: EPA; numbers rounded.

To explore a future in which the United States powers itself both independently and cleanly, DISCOVER teamed up with the National Science Foundation, the Institute of Electrical and Electronics Engineers, and the American Society of Mechanical Engineers to organize a series of briefings on Capitol Hill. The presentations brought lawmakers together with eight leading energy scientists (see list at bottom of page) and policy experts to map out the road to a new energy economy. This is the way forward.


Bold Idea: Reengineer the grid around electric vehicles. The first mainstream plug-in hybrids and fully electric vehicles (EVs) are just now hitting the market, and while initial sales have been slow, the Department of Energy predicts there will be 1.2 million of them on the road by 2015. With the EV revolution in full swing, University of Michigan mechanical engineer Jeffrey Stein says the time is now to integrate the electrical grid with the transportation infrastructure and ensure the country’s carbon emissions drop as a result of the introduction of electric cars.

Transportation is responsible for 27 percent of America’s carbon emissions. Power companies’ heavy reliance on coal-fired plants means that electricity generation accounts for even more, about 33 percent. “At first it may seem counterintuitive that making cars electric will help us limit greenhouse gases,” Stein says. “But in fact we can reduce carbon emissions by adopting vehicle electrification.” The keys will be limiting the need for new power plants and engineering the electrical grid to increase the use of clean energy sources.

The Science Behind It Designers of both the electrical grid and future evs will have to take into account when and how owners charge their vehicles. “Eighty percent of charging is expected to take place at home or the workplace,” says Genevieve Cullen, vice president of the Electric Drive Transportation Association. Influencing when people recharge their cars could have huge implications for the effect of evs on the environment.

During off-peak hours, electric companies rely on the base load power generated in large part by carbon-neutral nuclear power plants; when demand rises during peak hours, they bring dirty, coal-fired plants online to meet increased need. “Utilities need to give electric vehicle owners preferential pricing for charging during off-peak hours, when energy is cleaner,” Stein says. The other half of the equation, he notes, is engineering a smart power grid that can distribute renewable energy, from solar or wind, for instance, to charge fleets of EVs. “If a power company has the ability to selectively charge groups of vehicles based on when renewable energy resources are available,” he says, “it makes electric vehicles useful not only for reducing petroleum consumption but for reducing the amount of greenhouse gases overall that we produce.”

Next Steps The Obama administration recently announced fuel economy standards that require the average new vehicle to go from 32.9 miles per gallon today to 35.5 mpg by 2016 and 54.5 mpg by 2025. Electric vehicles will have to become a significant part of the vehicle mix to meet those new mandates. But as Cullen points out, today’s EVs are far too costly for the average consumer, even with substantial tax breaks. “We need public and private investment in research and development, particularly in batteries and advanced technology that can help bring down manufacturing costs,” she says. In the last five years, improvements in batteries have driven down the price per kilowatt-hour of electric storage in an ev from $1,000 to $600, and the industry hopes to reach $300 by 2015. Cullen also suggests new state and local efforts to jump-start the ev infrastructure. “We need new policies to give electric vehicles parking preference and new building codes to ensure the development of charging stations.” If costs come down, electric vehicles could become very appealing, since their driving cost per mile can be extremely low. They also make an enticing environmental case: If you have a car that runs on electricity, any improvement that makes the electrical grid cleaner will make your own vehicle cleaner, all without your having to do a thing.

This report was authored by Genevieve Cullen, vice president, Electric Drive Transportation Association; Alan Epstein, vice president, technology and environment, Pratt & Whitney; paul Genoa, director, policy development, Nuclear Energy Institute; Daniel Ingersoll, program manager, nuclear technology, Oak Ridge National Laboratory; Connie L. Lausten, principal, cLausten LLC; Jeffrey Stein, mechanical engineer, University of Michigan; Amadeu K. Sum, chemical engineer, Colorado School of Mines; Donald Weeks, biochemist, University of Nebraska at Lincoln

Existing reactors circulate water from the core to a steam generator. Modular reactors house all the components in one vessel, reducing the risk of accident. Some designs are so simple they could be switched on and buried for years.


Bold Idea: Build a new generation of small, modular, ultrasafe nuclear reactors. The meltdown at Japan’s Fukushima plant last spring cast the issue of nuclear safety in stark relief. At the same time, nuclear reactors are still the only option for generating electricity on a large scale with no carbon emissions. Small modular reactors offer a better way to harness nuclear energy to produce power, says Daniel Ingersoll, a nuclear engineer and senior program manager at Oak Ridge National Laboratory. “All the designs for small modular reactors eliminate the features in larger plants that can contribute to a potential accident,” he says. Not only are they safer, but modular reactors are (relatively) cheap. The price tag for a conventional, 1,600-megawatt nuclear power plant is about $8 billion to $10 billion, assuming anyone could get approval to build it. A 300-megawatt, $850 million modular unit is a much more plausible proposition, and it could be fabricated using domestic supply chains. “That means more high-tech jobs in the United States,” Ingersoll says. “And it gives us an opportunity to regain leadership in nuclear energy.”

The Science Behind It Conventional nuclear power plants circulate water through a reactor core, where it is heated and then passed via pipes to larger vessels, where it converts to steam. “What scared the bejeebies out of early designers was the prospect of a double break of the pipe that connects the two vessels,” Ingersoll says. “If that happened, you would drain the reactor of its coolant very quickly, and nasty things happen once you uncover the core.” Conventional plants have a number of systems to prevent the core from being uncovered, but modular reactors sidestep the problem entirely by housing all the system components, including the steam generators, inside a single vessel. “These designs are fundamentally different from the large plants producing electricity today,” Ingersoll says. “They are elegantly simple and eliminate accidents that could result from loss of coolant.” There are some 50 modular designs being developed globally, and while many are traditional light water reactors, which use water to cool the reactor core, others gain efficiency by using coolants such as gas, which allow reactors to reach higher temperatures.

Next Steps The Nuclear Regulatory Commission is working with the Nuclear Energy Institute, an industry group, to revamp the licensing procedure for nuclear power plants to include new rules tailored to small modular reactors. “The existing regulatory paradigm must change,” says Paul Genoa, director of policy development at the Nuclear Energy Institute. “There shouldn’t be any reduction in the safety of the operation of these plants. But we need to change the regulatory structure to allow for more flexibility in introducing multiple designs.”

The Tennessee Valley Authority recently announced plans to build the nation’s first small modular reactor in eastern Tennessee. If it receives funding and passes regulatory hurdles, the reactor could be operational by 2020 and power up to 70,000 homes. The Department of Energy is developing a prototype modular reactor at its Savannah River site in Georgia, and Argonne National Laboratory in Illinois and Sandia National Laboratories in New Mexico are also considering modular plants.

Meanwhile, other countries like Russia and China are fast-tracking similar projects. “We’re in a race,” Genoa says. “When we deploy these new small reactors, will we build them at home or buy them from China?”


Bold Idea: Extract frozen gas from permafrost or from the ocean floor to power new, ultraefficient turbines.Natural gas, which now supplies 25 percent of the nation’s electricity, is the cleanest-burning fossil fuel, producing about half as much carbon per watt of power as coal. “If you have to burn fossil fuels and you care about the environment, you want to burn natural gas,” says Alan Epstein, vice president of technology and environment at Pratt & Whitney, which manufactures gas turbines. Natural gas is also abundant, which helps account for its growing popularity. Use of natural gas to generate electricity increased 5 percent in the first five months of this year alone. The United States has about 284 trillion cubic feet of natural gas in proven reserves, an 11-year supply. Far more is locked away in frozen deposits called methane gas hydrates. Globally, the hydrates may contain 700,000 trillion cubic feet of natural gas—enough to power the United States for 1,000 years at current rates of consumption.

The Science Behind It Gas turbines are essentially rugged jet engines strapped to electric generators. A research project funded by the Department of Energy for nearly two decades has boosted the efficiency of gas-fired power plants to 60 percent, beating every other energy source. “It’s the most efficient device humankind knows to turn thermal energy into power,” Epstein says. Gas turbines are also attractive because natural gas is relatively cheap and abundant, due in part to the introduction of hydraulic fracturing technology, or fracking, which uses high-pressure water to extract hydrocarbons from previously inaccessible shale deposits. Fracking also has some unappealing, highly publicized environmental effects, but an even more plentiful alternative source of natural gas may soon be available.

Gas hydrates naturally form along the coasts of continents and in Arctic permafrost, places where water and gas mix at relatively high pressure and low temperature. Under such conditions, water molecules assemble into icelike crystal structures that trap methane. These structures hold a remarkable quantity of gas, according to Amadeu K. Sum, a chemical engineer and director of the Center for Hydrate Research at the Colorado School of Mines. One cubic meter of gas hydrate on the ocean floor contains 165 cubic meters of gas at room temperature and pressure. “The energy potential of these hydrates is vast,” Sum says. “In total they contain twice as much carbon as all the fossil fuels on the planet.”

Next StepsDespite all the recent advances, gas turbines still have room for improvement. If natural gas–fed turbines could increase efficiency by just another 5 percent, it would save $180 billion by 2040 in electricity costs. “I’m an optimist,” Epstein says. With further federal funding for research and development, “I think we can get to 70 percent efficiency.”

Methane hydrates are a promising way to keep those turbines humming. A report by the National Research Council examined the technical challenges to recovering methane hydrates and concluded that none are impossible to overcome. An international rush on methane hydrates is already on, Sum says. China, India, and South Korea have begun methane hydrate drilling projects, and Japan has invested a billion dollars in a test production program. The Department of Energy received $5 million for methane hydrate research and development in fiscal year 2011; an experimental well on Alaska’s North Slope, dubbed Ignik Sikumi (Inuit for “fire in the ice”), will go into production in 2012. Still, “other nations are way ahead of the United States and are outspending us by at least a factor of 10,” Sum says.


Bold Idea: Power cars with pond scum.Corn and sugarcane are well-established sources of biofuel, but algae are more efficient than either—more efficient even than much-touted switchgrass. Some algae species contain up to 60 percent oil, and genetic engineers say they can boost that percentage even higher. And unlike the corn used to produce ethanol in the United States, algae do not compete with food for farmland, one of the biggest problems with current biofuels. “Algae can grow on marginal land, even in agricultural and human wastewater,” says Donald Weeks, a University of Nebraska at Lincoln biochemist. “They are sustainable, highly productive, and easy to cultivate, and they capture carbon dioxide.”

If oil-intensive algae were cultivated on a broad scale—the kind of scale now used for other commercial crops—they could eventually replace the 70 percent of the U.S. oil supply used for transportation in the form of jet fuel, gasoline, and diesel, according to Weeks. In the nearer term, “if you look at production, algae get 5,000 gallons per acre,” he says. If 60 million acres of land, approximately the area of Oregon, were given over to algae cultivation, “we could reasonably produce 300 billion gallons of algae biofuels per year.” We would need 460 billion gallons to replace all the gasoline Americans consume in a year.

The Science Behind It The key to cultivating algae as a biofuel is genetically manipulating them to produce more oil than they do naturally. Until now, geneticists have studied only one species in any depth: a common single-celled green alga called Chlamydomonas reinhardtii. But thousands of other species are possible sources of biofuel. “The science here is still in its infancy,” says Weeks, who compares today’s algae specialists to the ancient Mesoamericans who domesticated teosinte, the slender, meager grain that was bred into modern corn after some 8,000 years of cultivation. “In terms of algae genetics, we’re back in the teosinte days,” he says.

A recent breakthrough may help advance the process. Researchers have long known that when algae are starved of nitrogen they produce more oil. Unfortunately, nitrogen-starved algae also grow more slowly. Scientists at Sapphire Energy, a San Diego–based biofuel company, found a way around this problem when they discovered a gene that produced high oil yield even in the presence of nitrogen. By manipulating this gene, the researchers managed to engineer algae that both grow rapidly and yield a lot of oil. “We’ve only begun to tap the science of algae biofuel,” Weeks says.

Next StepsAlgae biofuels should benefit from recent changes to the Renewable Fuel Standard, a set of regulations that require gasoline in the United States be blended with a certain amount of renewable fuel. The statute mandates that 36 billion gallons of biofuels be produced annually by 2022, a big jump from the 7.5 billion gallons to be produced in 2012. Of that total, 21 billion gallons must come from sources that reduce greenhouse-gas emissions by 50 percent or more—a goal that algae neatly achieve. But Connie L. Lausten, principal of the green lobbying firm cLausten llc, worries that the current regulations are too specific. “The biofuel tax incentives are all over the map,” she says, noting a wide disparity in support depending on which raw material is being used. “We need the same level of tax incentives and grants for all these fuels. Don’t pull the rug out from under a technology when it’s just taking off.” Ramping algae biofuels up to commercial-scale production will also be a challenge: Going from 0 to 60 million acres will require considerable research, development, and investment. But the oil industry grew similarly dramatically 150 years ago. If the economics and environmental incentives pan out, biofuel made from algae could do it too.

The Defense Advanced Research Projects Agency, or DARPA, is responsible for some of the most groundbreaking government-
sponsored innovations, including a little thing called the Internet. A new agency called Arpa-E aims to bring the same far-forward thinking to energy research (the E stands for “energy,” of course). It supports projects that have uncertain odds of success but a huge potential upside. In 2009 Arpa-E began distributing $151 million to 37 projects. Here are five of the top projects the agency is betting will transform the way we consume energy.

Wave Disk Engine

Inside your car’s engine, combustion gases expand as gasoline is burned, creating force that drives a piston. It is an effective system, but it converts only about 15 percent of fuel energy into propulsion. Michigan State mechanical engineer Norbert Müller aims to do far better with his wave disk engine, in which a rotating wheel sucks fuel and air into small internal channels. As the wheel spins, ports on the outer rim of the engine block the fuel-air mixture from flowing out of the channels. The blockage creates shock waves, and the resulting pressure helps the fuel to ignite, pushing against curved blades on the disk and causing it to spin. Müller says his engine has the potential to be 60 percent efficient. He hopes to finish a prototype large enough to power an SUV by next year.

Arpa-E’s bet: $2,540,631

Fuel from Bacteria

What will you pump into the tank of tomorrow’s hyperefficient car? Columbia University engineer Scott Banta and his team propose that the ideal microbe for creating a renewable fuel is actually Nitrosomonas europaea, a bacterium that naturally feeds on ammonia and carbon dioxide. The researchers are genetically engineering it to churn out butanol, an alcohol that burns like gasoline. Not only can N. europaea convert ammonia into energy, but the bacterium sucks carbon out of the atmosphere in the process. Banta imagines siting bacteria farms near coal plants to convert troublesome carbon emissions into valuable fuel. He is now working to get the bacteria to produce butanol on a large scale.

Arpa-E’s bet: $543,394

Carbon Sponge

Carbon-capture technology can make coal plants nearly emission-free right now, but the process gobbles up about a quarter of the energy produced. Joe Zhou, a chemist at Texas A & M University, has devised a way to reduce the power drain. Current capture methods absorb carbon dioxide into ammonia-derived solvent solutions, which then must be heated intensely to release the trapped gas. Zhou’s technique uses metal and carbon-based frameworks that change their structure in response to slight changes in temperature, magnetic fields, and light. “When you change the structure, it’s easy to push the carbon dioxide out,” Zhou says. The system should be ready for large-scale testing within a few years.

Arpa-E’s bet: $1,019,874

Utility-Scale Battery

Wind and solar power are clean but inconveniently intermittent. To keep the power flowing, MIT materials scientist Donald Sadoway proposes building storage batteries large enough to power whole neighborhoods. Inside his prototype are three layers of molten fluid: magnesium, antimony, and an electrolyte solution that transfers magnesium ions (charged atoms) to the antimony, producing an electric current. Compared with other batteries, this design is relatively cheap, and it can be scaled up to hold enough surplus electricity for a subdivision or a hospital, releasing it when needed. “After dark or when the wind isn’t blowing, you’ll still have uninterrupted power,” Sadoway says.

Arpa-E’s bet: $6,949,584

Cheap Solar Electricity

Another big drawback of solar power is cost: The silicon wafers that absorb sunlight and turn it into electric current can run upwards of $130 a pound because of a complex fabrication process that involves melting silicon, letting it crystallize into large ingots, and cutting it into thin wafers. Massachusetts-based 1366 Technologies simplifies things by repeatedly skimming the solid “skin” off the top of a pool of molten silicon. Mechanical engineer Frank van Mierlo, 1366’s CEO, says this method should cut the cost of photovoltaic wafers by two-thirds. “Ideally, we could produce electricity with solar at the same price you can produce electricity with coal.”

Arpa-E’s bet: $4,000,000

—Elizabeth Svoboda

2 Free Articles Left

Want it all? Get unlimited access when you subscribe.


Already a subscriber? Register or Log In

Want unlimited access?

Subscribe today and save 75%


Already a subscriber? Register or Log In