Research into renewable energy, batteries, carbon capture and storage, the electric grid and natural gas have sprung up around campus, helping to move the world to a more sustainable future.
Batteries to store their intermittent energy are not yet cheap and powerful enough to fill the gaps. Nuclear energy produces no greenhouse gases directly, but the current generation of reactors has other problems. Solutions like storing carbon dioxide underground or turning it into clean fuel are promising, but they also need much development. None of the possible solutions is without challenges. Eight Stanford researchers describe how, among these many developing options, they envision the world becoming less reliant on fossil fuels.
Nobel physicist and former U. Other professors describe pathways to better technologies, as well as the public policies and financial mechanisms necessary for the best applications to flourish. All agree that the goal is less reliance on carbon-based fuel sources, and that a combination of solutions — rather than a silver bullet — likely will create that greener energy future. The long answer about our next fuel is not so grim, however. In fact, plenty of contenders for the energy crown now held by fossil fuels are already at hand: wind, solar, even nuclear, to name a few.
But the successor will have to be a congress, not a king. Virtually every energy expert I met did something unexpected: He pushed not just his own specialty but everyone else's too. The big problem is big numbers. The world uses some billion kilowatt-hours of energy a day. It's equal to about 22 bulbs burning nonstop for every person on the planet.
No wonder the sparkle is seen from space. Hoffert's team estimates that within the next century humanity could use three times that much. Fossil fuels have met the growing demand because they pack millions of years of the sun's energy into a compact form, but we will not find their like again. Fired up by my taste of energy freedom, I went looking for technologies that can address those numbers. The answers are out there. But they all require one more thing of us humans who huddle around the fossil fuel fire: We're going to have to make a big leap—toward a different kind of world.
On a cloudy day near the city of Leipzig in the former East Germany, I walked across a field of fresh grass, past a pond where wild swans fed. The field was also sown with 33, photovoltaic panels, planted in rows like silver flowers all turned sunward, undulating gently across the contours of the land. It's one of the largest solar arrays ever. When the sun emerges, the field produces up to five megawatts of power, and it averages enough for 1, homes. Nearby are gaping pits where coal was mined for generations to feed power plants and factories.
The skies used to be brown with smoke and acrid with sulfur. Now the mines are being turned into lakes, and power that once came from coal is made in a furnace 93 million miles million kilometers away. Solar electric systems catch energy directly from the sun—no fire, no emissions.
Some labs and companies are trying out the grown-up version of a child's magnifying glass: giant mirrored bowls or troughs to concentrate the sun's rays, producing heat that can drive a generator. But for now, sun power mostly means solar cells. The idea is simple: Sunlight falling on a layer of semiconductor jostles electrons, creating a current.
Yet the cost of the cells, once astronomical, is still high. Like most things electronic, solar power has been getting cheaper. Tomorrow, he says, it will make sense for almost everyone.
Martin Roscheisen, CEO of a company called Nanosolar, sees that future in a set of red-topped vials, filled with tiny particles of semiconductor. He won't say exactly what the particles are, but the "nano" in the company name is a hint: They are less than a hundred nanometers across—about the size of a virus, and so small they slip right through skin. Roscheisen believes those particles promise a low-cost way to create solar cells. Instead of making the cells from slabs of silicon, his company will paint the particles onto a foil-like material, where they will self-assemble to create a semiconductor surface.
The result: a flexible solar-cell material 50 times thinner than today's solar panels. Roscheisen hopes to sell it in sheets, for about 50 cents a watt. At that price solar could compete with utilities and might take off. If prices continued to drop, solar cells might change the whole idea of energy by making it cheap and easy for individuals to gather for themselves.
That's what techies call a "disruptive technology. We believe solar electric systems will be disruptive to the energy industry.
Yet price isn't the only hurdle solar faces. There are the small matters of clouds and darkness, which call for better ways of storing energy than the bulky lead-acid batteries in my system. But even if those hurdles are overcome, can solar really make the big energy we need? With solar now providing less than one percent of the world's energy, that would take "a massive but not insurmountable scale-up," NYU's Hoffert and his colleagues said in an article in Science.
At present levels of efficiency, it would take about 10, square miles 25, square kilometers of solar panels—an area bigger than Vermont—to satisfy all of the United States' electricity needs.
But the land requirement sounds more daunting than it is: Open country wouldn't have to be covered. All those panels could fit on less than a quarter of the roof and pavement space in cities and suburbs. Wind, ultimately driven by sun-warmed air, is just another way of collecting solar energy, but it works on cloudy days.
One afternoon I stood in a field near Denmark's west coast under a sky so dark and heavy it would have put my own solar panels into a coma. But right above me clean power was being cranked out by the megawatt. A blade longer than an airplane wing turned slowly in a strong south breeze.
It was a wind turbine. The turbine's lazy sweep was misleading. Each time one of the three foot meter blades swung past, it hissed as it sliced the air. Tip speed can be well over miles kilometers an hour.
This single tower was capable of producing two megawatts, almost half the entire output of the Leipzig solar farm. In Denmark, turning blades are always on the horizon, in small or large groups, like spokes of wheels rolling toward a strange new world. Denmark's total installed wind power is now more than 3, megawatts—about 20 percent of the nation's electrical needs.
All over Europe generous incentives designed to reduce carbon emissions and wean economies from oil and coal have led to a wind boom. The continent leads the world in wind power, with almost 35, megawatts, equivalent to 35 large coal-fired power plants. North America, even though it has huge potential for wind energy, remains a distant second, with just over 7, megawatts. With the exception of hydroelectric power—which has been driving machines for centuries but has little room to grow in developed countries—wind is currently the biggest success story in renewable energy.
He's director of project development for a Danish energy company called Elsam. He means not only the number of turbines but also their sheer size. In Germany I saw a fiberglass-and-steel prototype that stands feet meters tall, has blades feet 61 meters long, and can generate five megawatts. It's not just a monument to engineering but also an effort to overcome some new obstacles to wind power development.
One is aesthetic. England's Lake District is a spectacular landscape of bracken-clad hills and secluded valleys, mostly protected as a national park. But on a ridge just outside the park, though not outside the magnificence, 27 towers are planned, each as big as the two-megawatt machine in Denmark. Many locals are protesting. Danes seem to like turbines more than the British, perhaps because many Danish turbines belong to cooperatives of local residents.
In October its researchers developed a small fusion reactor design—one that might someday fit in a tractor-trailer and produce megawatts of power. The company hopes to have a working prototype in five years and a commercial version within a decade. Wind power promises to gain massive adoption in 25 years as advances in turbine blade designs are borrowed from aeronautics technology to derive the maximum amount of energy from each gust of wind.
Wind turbines will also increasingly move offshore, where countries like Denmark are already showing the rest of the world just how effective offshore wind energy can be. Wind power already provides a third of the country's power and is expected to provide a full 50 percent by Offshore installations like the turbine Anholt farm, completed last year, provide some 1.
And because offshore wind resources tend to blow stronger and more consistently than onshore installations, intermittency is less of a problem. In the decades ahead, geothermal energy is expected to boom as scientists find a commercially viable way to tap energy deep beneath the Earth's crust. Overseas, researchers in Iceland have spent several years drilling straight into volcanoes to access very hot water and magma deposits, with an eye toward eventually developing these high-temperature resources into far more prolific geothermal power stations.
The goal is to develop more advanced technologies that can be exported in the next decade. If that research pays off, it could soon be possible to tap much hotter geothermal resources around the globe that can produce 10 times as much energy as today's geothermal facilities. It might even one day be feasible to drill geothermal wells offshore; researchers estimate that massive stores of heat energy are reachable just 1, meters below the seabed at the Juan de Fuca Ridge off the coast of Washington state.
Space-based energy technologies—things like harvesting hydrogen from the moon to power fuel cells on Earth, or orbiting solar arrays that absorb around-the-clock direct sunlight and beam the energy back down to stations on the ground via radio or microwaves—remain firmly in the realm of science fiction for now.
That is why most projections predict energy additions taking place -- rather than transitions. In the graph above outlining the projections of the primary global energy consumption by fuel, coal consumption would increase or remain flat under half of the scenarios described here.
Natural gas consumption will grow under every scenario, while liquids consumption will grow in all but 2 scenarios. The share of nuclear power is highest under Ambitious Climate scenarios. Renewable energy, led by wind and solar power, grow rapidly, though they primarily add to, rather than displace, fossil fuels unless more ambitious climate policies are put into place.
Emissions concerns, economic growth, demand, and trade, will mean difficult policy choices for national governments and energy majors. These decisions will come to define the globe's future energy landscape. The GEO provides a coherent compilation of these forecasts and offers us the best glimpse of that future so far.
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