The Future of Energy: A Realist's Roadmap to 2050
Which technologies will finally free us from oil?
The Future of Energy
This December, when representatives from 170 countries meet at the United Nations climate talks in Copenhagen to replace the expiring Kyoto climate treaty, the smart money predicts unprecedented collaboration. American political change coupled with spiking carbon dioxide levels could inspire a communal project on a scale not seen since World War II. A consensus, backed by science, is emerging among the international community that by 2050 we need to reduce emissions of C02, methane and other greenhouse gases to approximately 80 percent lower than they were in 1990.
It will mean a wholesale reinvention of the global energy economy; anything less could result in catastrophe. Here's how we'll get there.
To reach this goal will require a two-pronged approach. First, we have to get serious about the small stuff: better insulation, tossing the incandescent light bulbs and, yes, inflating our tires all the way. Second, we need to scale up every low-carbon energy source we have — wind, solar, nuclear — pretty much immediately. Our realist's road map to 2050 shows how we get there:
Harnessing the terrawatts of energy we get from the sun
Subtle movements create current
Beyond ethanol
Turbines to take root in the sea
Six Generation III+ reactors set for the U.S.
Energy from the Earth's core comes to the surface
Carbon-capture technology comes on the scene
The Plan to Build the Next Electric Grid
Even if we tap every renewable power source available, it won't mean a thing without a final, crucial step: reinventing the grid
Harnessing the terawatts of energy we get from the sun
Solar paneling Nick Kaloterakis and Kevin Hand
The Big Picture: "Solar power" no longer refers just to chunky photovoltaic panels. A variety of tools for turning sunlight into usable energy — thin-film solar, solar thermal, solar heating, and more — are undergoing a burst of technological acceleration. Whether it's powering an entire housing development or simply heating your house, taken together, their potential is huge
Where We Are: 12.4 GW
What We Need by 2050: 2,000 GW
Tech to Watch: Concentrating Solar Thermal
A shortage of low-carbon power sources seems absurd when you consider that a nearby star bathes the planet in 85,000 terawatts of energy every year. We just have to capture it.
The Google-funded start-up eSolar has devised a relatively cheap and efficient form of solar power by refining concentrating solar thermal (CST), in which large mirror arrays focus light to create heat and ultimately electricity. Proponents say CST can make solar cost-competitive with coal within a decade. It is "probably the only thing that can be done at a big enough scale to produce terawatts," says Bill Gross, eSolar's CEO.
At the first eSolar power plant, a five-megawatt facility called Sierra situated northeast of Los Angeles, 24,000 mirrors gather the sunlight falling on 20 acres of land and train it on water-filled boiler units perched on top of towers. This creates temperatures of approximately 850°F, producing steam that turns an onsite turbine to generate electricity.
CST has been around since 1980, but in the 1990s a lack of public interest sent it into hibernation. Now public interest is back in a big way, and CST has awoken with a vengeance. One new megawatt of CST hardware was installed worldwide in 2006; in 2007 there were 100. The Earth Policy Institute projects that the installation of CST worldwide will double every 16 months, from 457 megawatts in 2007 to 6,400 megawatts by 2012. At least 13 plants are in advanced planning stages in the U.S.
ESolar's approach is comparatively cheap because, unlike most of its competitors, which use large, custom-built parabolic mirrors to capture sunlight from all angles, eSolar uses small, flat mirrors, each about the size of a big-screen television. Computerized tracking keeps each mirror focused at the optimal angle throughout the day. The mirrors are easy to manufacture, and it takes just two workers to attach them to relatively light scaffolding on-site. ESolar's standard 46-megawatt array, which makes enough juice to power about 30,000 homes, occupies only a quarter of a square mile, which will allow the company to avoid the land-use fights that have ensnared other solar companies.
Sierra is a demonstration project, but in February eSolar signed a deal to build 11 46-megawatt plants in the Southwest, and it is set to build a full gigawatt's worth of plants in India. "Efficiency wins in every industry," Gross says, "and it's going to win in solar as well."
Subtle movements create current
River Running Workers attach a walkway to the nation’s first commercial hydrokinetic power turbine, on the Mississippi River in Hastings, Minnesota Mark Stover/ Hydro Green Energy
The Big Picture: Conventional hydroelectric power (think of the Hoover Dam) provides 7 percent of the electricity in the U.S. But the only way to increase that number without damming more rivers — which causes widespread ecological damage both above and below the dam — is to use nonconventional hydropower sources that capture energy from the movement of waves, rivers and tides.
Where We Are: 31 GW
What We Need by 2025: 67 GW
Tech to Watch: Hydrokinetic Power
The future of hydropower is taking shape just downstream from a standard hydroelectric dam in Hastings, Minnesota. The power isn't hydroelectric, though; it's hydrokinetic, generated from the motion of free-flowing water.
Installed this winter in –30° weather and switched on in January, the Houston-based Hydro Green Energy's pilot plant is the first federally licensed hydrokinetic project in the U.S. Like an underwater wind turbine, it will produce electricity by using the high-velocity current gushing out of an existing hydroelectric dam to turn a 12-foot, three-blade fan. Known as "run-of-river" hydrokinetic, Hydro Green's technology is similar to turbines that are being used to tap tidal power in Europe, except it's optimized to work in water flowing in just one direction (tidal turbines use water flowing both in and out).
To generate utility-scale power, turbines would be combined into arrays. They could be used in free-flowing rivers too, but coupling them with existing hydroelectric dams eases the Federal Energy Regulatory Commission's licensing process and offers close access to the electricity grid. Hydro Green says that its technology can create power much more cheaply than a windmill can (4 to 7 cents per kilowatt-hour, compared with 10 cents per kilowatt-hour for wind).
The main goal of the plant, which is rated for 100 kilowatts — enough to power 40 homes — is to answer some essential, basic questions: How do you build blades strong enough to withstand the constant flow of water? (Another company, Verdant, installed an experimental hydrokinetic project in New York City's East River in 2007, only to have the rotors snap days later). How do you balance the presence of a turbine with the local ecosystem — for example, how does a hydrokinetic plant affect the river's fish population? This spring, Hydro Green embarked on a $500,000 study to determine the impact of the turbines on six species of river fish, and a second, 150-kilowatt turbine will soon be up and running.
Beyond ethanol
Energy Bugs Researchers are perfecting ways to turn algae — like the sargassum seaweed seen here — into biodiesel and to use methylococcus microbes to turn carbon dioxide into methane, the main ingredient in natural gas Nancy Sefton/Photo Researchers
The Big Picture: Ethanol is the most widely used biofuel today, but it's hardly a panacea to our energy woes. Researchers are scrambling to transform more- efficient organic materials — switchgrass, sugarcane, algae, sewage and even medical waste — into low-emission fuel for both transportation and electricity generation.
Where We Are: 643,000 barrels per day
What We Need by 2050: 34 million per day
Tech to Watch: Algae
The canals of Venice, Italy, may soon provide a green power source for the city's seaport and prove that algae-derived energy can meet commercial electricity demand.
A $272.6-million plant is awaiting authorization to generate electricity by burning biodiesel fuel made from canal algae. To get the fuel for the plant, algae harvested from the canal will be cultivated in 26-foot plastic bioreactors (and fertilized with carbon dioxide from the plant itself), dried, expeller-pressed to squeeze oil-like lipids from the dried biomass, and turned into biodiesel through the addition of lye. By 2011, the plant could generate 40 megawatts, which would be used to power the city's seaport and channel the excess electricity — 33 megawatts — to docked tankers and cruise ships, all with zero net carbon emissions.
The Venice project won't be cost-effective; it's designed as a technology demonstrator and to give the city a jump on expected stricter cap-and-trade legislation. In the meantime, however, other innovations promise to finally make algal power affordable. While centrifuges account for 34 percent of the total investment costs, there is now a cheaper way to separate the algae from the water they grow in. In March, AlgaeVenture Systems in Ohio announced a new method to "dewater" algae using capillary action: A superabsorbent polymer pulls water molecules through a membrane and leaves the algae dry. The company claims that the process reduces biofuel production costs from $875 per ton to just $1.92. Advances in algal oil extraction and the conversion to biodiesel should bring expenses down even further.
Although there are currently no plans for a commercial plant in the U.S., companies like BioProcess Algae are hoping to change that. BioProcess recently received a grant to build a pilot plant in Shenandoah, Iowa. If successful, prototype plants like this one could eventually help make domestic algae power more than a curiosity.
The Perfect Biofuel?
The technology is still experimental, but late last year researchers at Penn State University discovered how to make methane — a main ingredient in natural gas — from the very thing driving climate change: carbon dioxide. The key is microorganisms called methanogens. Engineer Bruce Logan discovered that the organisms produced methane with nothing but water and carbon dioxide when zapped with an electric current. Build a fuel cell around the microbes, and as long as the electricity that feeds into the device comes from a renewable source like wind or solar, the process can provide a carbon-neutral source of combustible fuel.
Turbines to take root in the sea
Virgin Waters The Hywind project aims to perfect technology for floating windmills in the deep ocean, opening up new room for wind power to breathe Stephen Toner/Getty Images
The Big Picture: Wind power is all about location — getting turbines where the breeze blows steady and strong. One of the best places for that is far out at sea. And because one of the biggest obstacles to expanding wind power is overcoming the objections of residents who don't want wind farms blocking their views, deepwater wind, which is invisible from shore, has dual appeal.
Where We Are: 94 GW
What We Need by 2050: 2,000 GW
Tech to Watch: Deepwater Wind
According to the U.S. Department of the Interior, seabound wind farms off the Pacific coast could generate 900 gigawatts of electricity every year. Unfortunately, the water there is far too deep for even the tallest windmills to touch bottom. An experiment under way off the coast of Norway, however, could help put them anywhere.
The project, called Hywind, is the world's first large-scale deepwater wind turbine. Although it uses a fairly standard 152-ton, 2.3-megawatt turbine, Hywind represents "totally new technology," says Walter Musial, the principal engineer for ocean renewable energy at the National Renewable Energy Laboratory of the U.S. Department of Energy. The turbine will be mounted 213 feet above the water on a floating platform, or spar — a technology Hywind's creator, the Norwegian company StatoilHydro, draws from its experience as Scandinavia's largest gas and oil company. The steel spar, which is filled with ballast and extends 328 feet below the sea surface, will be tethered to the ocean floor by three cables; these will stabilize the platform and prevent the turbine from bobbing excessively in the waves. Hywind's stability in the turbulent, wintry Scandinavian sea would prove that even the deepest corners of the ocean are suitable for wind power. If all goes according to plan, the turbine will start generating electricity six miles off the coast of southwestern Norway as early as September.
To produce electricity on a large scale, a commercial wind farm will have to use bigger turbines than Hywind does, but it's difficult enough to balance such a large turbine so high on a floating pole in the middle of the ocean. To make that turbine heavier, the whole rig's center of gravity must be moved much closer to the ocean's surface. To do that, StatoilHydro plans to engineer a new kind of wind turbine, one whose gearbox (the mechanism that transfers power between the rotor and the generator) sits at sea level rather than behind the blades.
Hywind is a test run, but the payoff for perfecting floating wind-farm technology could be enormous. Out at sea, the wind is often stronger and steadier than close to shore, where all existing offshore windmills are planted. Deep-sea farms are invisible from land, which helps overcome the windmill-as-eyesore objection that has derailed wind farms in the past. If the technology catches on, it will open up vast swaths of the planet's surface to one of the best low-carbon power sources available.
Safer Nuclear
Six Generation III+ reactors set for the U.S.
Self-Serve Reactor Traveling-wave technology starts out with mostly "depleted" uranium (U-238) [A] — useless metal that's thrown out when traditional “enriched” uranium fuel (U-235) is created. A small amount of enriched uranium starts a heat-producing nuclear reaction. It ejects neutrons that meld with atoms of depleted uranium which, through a series of reactions, convert it into plutonium-239. The reaction moves like a wave [B] along the fuel, generating heat until all the uranium is spent [C] — a process that goes on for decades. Molten sodium metal [D] absorbs and carries away the heat to boil water and drive a steam turbine [not shown] Nick Kaloterakis and Kevin Hand
The Big Picture: It's nearly impossible to imagine making meaningful carbon dioxide reductions without designing safer, cleaner reactors and rolling them out immediately — because no one wants to build more of the reactors we have today.
Where We Are Now: 372 GW
What We Need by 2050: 700 GW
Tech to Watch: Next-generation Nuclear
Of all carbon-free energy sources, nuclear power is the only one that's already working on a large scale, generating 21 percent of America's electricity. It's also the one that freaks people out the most. Memories of Chernobyl, fears of terrorists getting nuclear material, and unease over waste that stays radioactive for tens of thousands of years all mean that before nuclear power can be expanded on an order needed to meet greenhouse-gas-reduction targets, engineers will need to build new reactors that help mitigate the unique dangers of nuclear fission.
In the short term, we'll have to settle for so-called Generation III+ reactors — simpler, safer and cheaper versions of the water-cooled behemoths that dot the landscape today. But 20 to 30 years down the line, things start to get much more interesting. Here's a look at the next few decades of nuclear power.
Generation III+
Design: Pressurized water
How it Works: Like today's reactors, these bathe enriched uranium fuel in water that absorbs heat to make steam.
Promise: Gen III+ pressurized-water reactors add "passive" safety mechanisms that cool the reactor if the plant loses power. For example, in an emergency, water flows from an extra tank above the reactor, driven by gravity.
Problems: Radioactive waste takes years to cool before it can be stored in underground repositories, which still don't exist.
Status: Mitsubishi-Westinghouse, which developed the design, has received approval from the U.S. Nuclear Regulatory Commission and has signed contracts to build six reactors in the U.S. and four in China.
Generation IV
Design: Pebble bed
How it Works: Tennis-ball-size graphite spheres (pebbles) filled with uranium dioxide fuel capsules are stacked in the reactor like gumballs, where they start a nuclear reaction. A pump sends helium into the reactor, where it flows around the pebbles, absorbs heat, and then drives a turbine.
Promise: If the coolant is lost, the graphite pebbles absorb enough heat to prevent the fuel from melting down.
Problems: A single reactor requires billions of perfectly manufactured fuel capsules. If oxygen seeps in, the fuel can catch fire. The reactor uses enriched uranium (also good for making bombs) and produces radioactive waste.
Status: Researchers have built and run small test reactors, but the design hasn't been commercialized.
Generation V
Design: Traveling wave
How it Works: Enriched uranium starts the process, releasing neutrons that help convert scrap depleted uranium (left over from enrichment plants) into plutonium. The plutonium releases yet more neutrons that convert more depleted uranium into usable fuel [see illustration above].
Promise: Very little enriched uranium is required, and there is already enough to last for centuries using this technology.
Problems: Cooling the reactor could require molten sodium, which catches fire if it comes into contact with oxygen or water. No one has built even an experimental traveling-wave reactor.
Status: A think tank called Intellectual Ventures wants to build a plant by 2020, but outside experts are skeptical, saying it could take decades.
Energy from the Earth's core comes to the surface
Fire and Ice Geothermal plants provide some 25 percent of Iceland’s electricity Stephen Toner/Getty Images
The Big Picture: Geologically active countries like Iceland can more than meet their needs with the energy that vents from the Earth, but other countries would benefit from expanding clean geothermal power as quickly as possible.
Where We Are Now: 10 GW
What We Need by 2050: 700 GW
Carbon-capture technology comes on the scene
Capture the Carbon The Dynegy power plant in Moss Landing, California, could be the first to use Calera’s carbon-to-cement emissions-scrubbing technology Courtesy Steve Marra
The Big Picture: Carbon-restricting legislation, if enacted, will discourage the use of coal, the dirtiest of all fossil fuels. Natural gas is cleaner but still emits carbon dioxide when burned. Both will be used for decades, but carbon-capture technology could clean them up until they can be replaced completely.
Where We Are Now: 1,460 GW
What We Need by 2050: 3,830 GW (all of it clean)
Tech to Watch: Carbon-to-cement
Electricity generation accounts for 35 percent of human-generated carbon dioxide emissions globally, and almost all of that comes from burning coal or natural gas. Production of cement — 2.9 billion tons of it worldwide every year — contributes another 5 percent of carbon dioxide every year. For the Silicon Valley start-up Calera, those are convenient facts. The company has found a way to slash emissions from two of the biggest greenhouse-gas sources simultaneously by turning carbon dioxide into the raw material for buildings and highways.
The basics are simple. Take the smokestack exhaust from a coal- or gas-fired power plant and run it through seawater. The carbon dioxide and other pollutants in the flue gases combine with magnesium and calcium in the seawater to form a kind of synthetic limestone. That material can then be processed into either cement or aggregate, the main ingredients in concrete and asphalt. The seawater, which is clean but depleted of magnesium and calcium, is sent back to the ocean. The technology is obviously best suited to the coasts, but inland, briny water drawn from overtapped aquifers could replace seawater.
Calera's process has a side benefit that could make it particularly attractive to the owners of existing coal- and gas-fired power plants: It traps the so-called criteria pollutants — sulfur dioxide, nitrogen oxides, particulates, heavy metals — that the Clean Air Act requires power plants to "scrub" from their smokestacks by 2012. Roughly half the plants in the U.S. haven't complied with the law, because of the expense and the fact that 20 percent of the electricity a plant produces would have to be used for scrubbing. Add a scrubber to separate out carbon — the most conventional route to clean coal — and you eat up another 20 percent. Total cost: $1.7 billion for a 500-megawatt plant. "If you own an old coal plant that's already at 35 percent efficiency, you're pretty much out of business," says Calera CEO Brent Constantz. In contrast, he estimates, it would cost $400 million for a 500-megawatt plant to install his company's technology.
The Plan to Build the Next Electric Grid
Even if we tap every renewable power source available, it won't mean a thing without a final, crucial step: reinventing the grid
The Next Grid: Nick Kaloterakis and Kevin Hand
The American electric grid is an engineering marvel, arguably the single largest and most complex machine in the world. It's also 40 years old and so rickety that power interruptions and blackouts cost the economy some $150 billion a year. The idea of building a connected "smart" grid that can route power intelligently is beyond daunting, no matter how much stimulus money gets thrown at it. But if we want to cut carbon, we have no choice. Today's grid simply cannot handle a large-scale rollout of the clean-energy sources outlined in this series.
In part that's because we need new high-voltage power lines to connect parts of the country where renewable resources are abundant (the sunny Southwest deserts, the windy Great Plains) to the cities and suburbs where more people live. But the more fundamental problem is that most renewable power sources don't behave like fossil-fuel sources — they can't be turned on and off on demand. Wind farms produce power only when the wind blows; solar, only when the sun shines. This is problematic, because power demand is twofold: We need "baseload" power that's predictable and steady, and "peak" power for daily spikes in demand (when, say, everyone arrives home and turns on their air conditioning). Intermittent renewables are not well suited to either. But with more power lines connecting power sources over a broader geographical area, renewables can simulate baseload power. (The wind is always blowing somewhere.) And a smarter grid cleverly shifting power demand around can redirect enough clean electricity to handle it when demand increases suddenly.
At a Small Scale: sensors will connect each appliance in your home to a smart meter. The meter will serve several purposes. One, it will provide detailed information on how much energy you’re using at any given time and what it’s costing you. Two, it will allow you to control your energy use remotely — from your office computer, for instance. Three, it could allow your electric utility to regulate your energy use for you, reducing power flow during peak demand hours Nick Kaloterakis and Kevin Hand
The idea behind the smart grid is to embed the system with sensors and computers so that utilities and consumers can precisely control power usage and delivery. Wireless nodes (on substations, transformers and wires) and smart meters (on homes and businesses) will communicate over the Internet to you and your electrical supplier. That way, when everyone turns on the A/C, the electric company can lower the power headed for other appliances, or even draw electricity stored in the battery of your plug-in hybrid, which, when parked, would act as a backup power source.
Rebuilding the entire grid and all its components could cost trillions, and it will require the coordinated efforts of hundreds of state and regional agencies, power-plant owners and electrical utilities. But the smart grid is already appearing piecemeal. By 2012, Southern California Edison, one of the country's largest electrical utilities, will install 5.3 million smart meters throughout San Diego and Los Angeles that will tell homeowners exactly how much power they're using at any given time — an important first step. The city of Boulder, Colorado, will soon finish building the country's first smart grid, with smart metering and a variety of sustainable energy sources. And President Obama's stimulus package includes $11 billion for smart-grid technology, to be used for research and demonstration projects.
Finally, a smart grid and a new network of high-voltage power lines to support it will make rolling brownouts a thing of the past. Let's get to it.
Last October, Iceland's economy tanked. Its bailout? A two-mile geothermal well drilled into a volcano that could generate an endless supply of clean energy. Or, as Icelanders will calmly explain, it could all blow up in their faces
The Kuwait of the North: Engineers at the Tyr drilling rig in Krafla’s snow-covered caldera hope to use a supercritical-water source two miles underground to produce 10 times as much geothermal electricity as a normal well Courtesy Sveinbjorn Holmgeirsson/Landsvirkjun Power
It's spring in Iceland, and three feet of snow covers the ground. The sky is gray and the temperature hovers just below freezing, yet Gudmundur Omar Fridleifsson is wearing only a windbreaker. Icelanders say they can spot the tourists because they wear too many clothes, but Fridleifsson seems particularly impervious. He's out here every few days to check on the Tyr geothermal drilling rig, the largest in Iceland. The rig's engines are barely audible over the cold wind, and the sole sign of activity is the slow dance of a crane as it grabs another 30-foot segment of steel pipe, attaches it to the top of the drill shaft, and slides it into the well.
Beneath the calm landscape, though, Fridleifsson and his crew of geologists, engineers and roughnecks are attempting the Manhattan Project of geothermal energy. The two-mile-deep hole they've drilled into Krafla, an active volcanic crater, is twice as deep as any geothermal well in the world. It's the keystone in an effort to extract "supercritical" water, stuff so hot and under so much pressure that it exists somewhere between liquid and steam. If they can tame this fluid — if it doesn't blow up their drill or dissolve the well's steel lining — and turn it into electricity, it could yield a tenfold increase in the amount of power Iceland can wrest from the land.
Iceland's geological evolution makes it especially well suited to harvesting geothermal energy. The island is basically one big volcano, formed over millions of years as molten rock bubbled up from the seafloor. The porous rock under its treeless plains sponges up hundreds of inches of rain every year and heats it belowground. Using this energy is simply a matter of digging a well, drawing the hot fluid to the surface, and sticking a power plant on top. Then, as power plants go, it's business as usual: Steam spins a turbine that drives a generator, and electricity comes out the other end. More than 50 countries use geothermal power; pretty much anywhere magma and water are within a few miles of the surface is fair game. Iceland ranks 14th in the world for geothermal resources but is the highest per-capita producer of geothermal power. It's committed to getting clean power out of the ground.
And commitment is what the rocky country needs right now. Last fall, Iceland entered a deep economic recession following a financial meltdown. Now, Iceland's economy is down to fishing, metals and its clean, limitless supply of geothermal energy. It's betting heavily on that energy, hoping to someday offload excess electricity to Europe through undersea cables, and Fridleifsson's project is the all-in wager of the game. Many countries dabble in green energy — a solar plant here, a wind farm there — as they try to wean themselves off oil and coal. Iceland, on the other hand, has been making zero-emissions power a reality since the oil shock of the 1970s, when its progressive inhabitants realized that their dependence on imported energy was an economic vulnerability. Fridleifsson's project, once just a scientific experiment, is the most recent expression of that ethos. If the gamble pays off, it could not only catapult Iceland out of debt but revolutionize renewable-energy efforts around the world.
From the Ground Up: Supercritical water from a 2.5-mile well[A] transfers its heat energy to clean water [B]. This creates steam, which drives a turbine [C] to generate electricity. A cooling circuit [D] absorbs excess heat and condenses the steam into water to reuse in the heat exchanger. Used supercritical water is pumped back underground [E] Paul Wootton
The process has been methodically slow, but after nearly a decade and $22 million, the Iceland Deep Drilling Project should hit supercritical water next month. Fridleifsson has already weathered one failed attempt, in 2005, when a well collapsed during a routine flow test. And so, close as he is, he's modest about his chances; when pressed, he admits to being "cautiously optimistic" about the current attempt. The project's risk assessor gives it a 50-50 shot at succeeding. Fridleifsson doesn't mention that if it works, a plant built around this well could deliver as much power as a small nuclear plant and become the global model for geothermal projects. And he certainly doesn't mention (as oilmen, solar engineers and wind farmers so often say of their work, but Fridleifsson actually deserves to of his) that it could rearrange the future of energy.
A Modest Proposal
Iceland turns geothermal energy into electricity in two ways: Venting 600°F steam from a mile underground through a turbine, and a more energetic method that pulls 390° water from deep wells and heats surface water, making steam to drive turbines. Harnessing a natural supply of supercritical water — water that's three times as hot and under enormous pressure — and turning it into electricity would be like switching from diesel to jet fuel. "If we succeed, we expect to increase power output by 5 to 10 times [above what a typical well can produce]," Fridleifsson says.
To appreciate the benefits of free supercritical water, it helps to understand that most coal plants and nuclear power plants make supercritical water before generating electricity. The plants transfer heat energy — produced by burning coal or by the radioactive decay of isotopes — to water in a pressurized tank to bring it to a supercritical state. The process allows the water to maintain the high-energy intermolecular hydrogen bonds of a liquid, yet flow through pipes with near-zero resistance like a gas. It then runs through heat exchangers to create even more steam, which drives turbines to make electricity.
The IDDP well will dip two and a half miles belowground into a pocket of water heated to 1,100° by a bubble of magma. Water normally exists as steam at this temperature, but the immense pressure of the rock above holds the water in a near-liquid state. Once the water squirts to the surface, it will retain nearly all the energy that heated and compressed it. It is virtually certain that engineers will have to redesign existing heat exchangers to handle the water's heat and potentially corrosive chemistry, but a plant running on naturally occurring supercritical water could churn out up to 500 megawatts, on par with a small nuclear reactor and half of what a large coal plant produces. Unlike these, though, the IDDP's zero-emissions power source will last as long as the Earth's core continues to heat rainwater.
Iceland's geothermal efforts are currently operating at 20 percent capacity. If it exploited the island's full reserves in only the conventional way, it could produce 20 terawatt-hours of electricity per year — about the same as three nuclear reactors. Tap into other supercritical reserves, or drill deeper into existing wells, and Iceland's electric output could be five times that of the U.S., the world's largest producer of geothermal electricity; Iceland is only the size of Kentucky.
In 2000, Fridleifsson recruited Wilfred Elders, a professor emeritus of geology at the University of California at Riverside, from retirement to co-lead the IDDP. Geological studies revealed that supercritical water does indeed flow under Iceland, and the six-mile-wide Krafla caldera was the place to go after it. They realized that all they have to do is tap the stuff — and hope that it doesn't destroy the drilling equipment in the process.
Dirty Work: The IDDP’s 23-inch drill bit grinds about 300 feet of rock from the well daily Courtesy Hjalti Steinn Gunnarsson/Isor
Fire in the Hole
Day at the Office: Typically stormy weather at the Krafla drilling site Sigurveig Arnadottir/Isor
Iceland has been running on geothermal power since the turn of the 20th century. Geothermal provides four terawatt-hours of electricity to the island a year, fulfilling about 25 percent of the country's consumption, in addition to nearly 90 percent of its heat and hot water. (The U.S. has an estimated 400 terawatt-hours in geothermal resources but produces just 14.8 terawatt-hours a year, which amounts to only 0.38 percent of its overall electricity consumption.) Iceland's international expertise on geothermal power, however, came with a steep learning curve. "We know better than anyone else how many things can go wrong," says Bjarni Palsson, the IDDP's head drilling engineer.
And with such a volatile fluid, a lot can go wrong. "Worst case, we have a blowout, and an uncontrolled flow of fluid blows the whole rig off," says engineering geologist Sebastian Homuth, who conducted the risk assessment of the project. This happened on one of Iceland's drilling projects in 1999, to incredible effect: The blowout left behind a 100-foot-wide crater. That explosion occurred because of a malfunction of the valve used to seal a wellhead in the case of a blowout. The IDDP's stop valve is strong enough to prevent an explosion from trashing the rig, but a blowout could make reopening the well difficult.
It's also likely that hydrochloric acid potentially present at these depths will make the water as caustic as battery acid. Engineers plan to strengthen the well with a steel lining, but "there is a good chance that this fluid is so corrosive that it will melt the steel within hours," Homuth says. As long as the fluid shooting up the well remains in steam form, as the engineers hope it will, the hydrogen and chlorine ions it carries cannot form hydrochloric acid. Unfortunately, no one will know either way until the fluid races to the surface. A more mundane failure is also possible — the drill could simply miss the supercritical water, or hit impenetrable magma, forcing Fridleifsson to abandon this site and drill elsewhere.
The team members have already drilled two miles, but their sensory gear can't withstand the hellish temperatures of the volcanic rock it will soon encounter, so they will drill the final 3,000 feet blind. The Tyr drilling rig works around the clock, grinding out 300 feet of rock per day, stopping every so often to take uncontaminated samples of the exotic rock. Elders and his team of mudloggers examine these rocks as they emerge from the well, searching for pyroxene-hornfels facies, the distinctive metamorphic rocks that indicate that the drill has hit its target. Regardless of the outcome at Krafla, the group will drill wells into two supercritical reservoirs on the west coast. Then, once they understand the supercritical fluid, they'll start figuring out how to turn it into electricity. "We're probably a dozen years away from a pilot plant," Elders says. "I might not live to see it."
The Patience to Be Bold
Iceland's high-pressure geology and volcanic activity make its geothermal plan a model for countries with a similar landscape. Japan and Italy are talking openly about the potential of their own supercritical water. But Iceland is the first country forced to bet everything on green energy, and its combination of desperation and expertise means it could finally make geothermal a viable alternative to oil and gas. As other nations run out of fossil fuels, they will face the same impetus. But you won't hear that from Fridleifsson. Perhaps it takes his kind of patience and modesty to make geothermal work. Fridleifsson insists that Krafla is just like hundreds of geothermal wells that he has drilled over the years. "There's no magic in this," he says. "It's just a natural process."
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