Prentiss says she wrote Energy Revolution out of a conviction that information is a powerful way to help people make decisions about energy use, whether as citizens or consumers. In order to effect change, then, her decision to focus on the largest, most inefficient sectors of the U.
The data also reveal that the most efficient sectors are the smallest. Transportation, the most inefficient sector by far, consumes 27 quads of energy, more than a quarter of total U. The largest, most inefficient sectors thus represent more than two-thirds of total energy consumption, and are the logical focus for moving the economy toward a sustainable future. The most wasteful example is a gasoline-powered car driven in the city.
The inefficiency begins with the engine itself, subject to the Carnot limit the thermal engine loss exceeds 65 percent of the energy in the fuel burned , and mounts from there: drivetrain losses, 4 percent; parasitic frictional losses, 6 percent; and other engine losses, 11 percent. In the final analysis, says Prentiss, just 16 percent of the energy actually moves the wheels.
Of every six gallons of gasoline burned, in other words, only one moves the car. In more efficient highway use, one gallon in four goes to turn the wheels—a yield of 25 percent. Electric cars are far more efficient. Their motors waste a negligible amount of power efficiencies can approach 99 percent , and regenerative brakes allow them to recapture and reuse much of the energy that propels the car. Overall, existing electric cars have total efficiencies that can exceed 60 percent. Thus, if gasoline-powered cars were completely replaced by electric cars, the electrical energy required to fuel them would be less than one-third the energy previously supplied by gasoline.
But Prentiss is not advocating that everyone buy an electric car now. That would cause demand for electricity to spike, and force utilities to burn more fossil fuels. Getting to efficient electric vehicles, in other words, also requires system change. The efficiency of the car and its impact on emissions is only as good as the efficiency of the plant that generates the power used to charge the battery. If the power to run those cars comes from a wind turbine or a solar panel on the roof of a home, then the electric car makes sense.
An energy economy based on electricity, including electric cars, must therefore grow gradually, Prentiss argues, with sources of supply and demand expanding in tandem in order to capture the efficiencies gained by eliminating heat engines. Furthermore, utilities must carry the capital costs of fossil-fuel-burning power plants on their books even as new renewable-power plants come on line.
Her data show that meeting growth in demand for electricity energy use grows over time by building new renewable energy plants, without decommissioning fossil-fuel plants before the end of their lives, leads to the smoothest transition to a sustainable economy.
Prentiss is realistic about the potential for change. Jets would still need to run on liquid fuel; doubling production of ethanol, a biofuel, could meet that need, she suggests. And even if the contiguous 48 states were to be linked by a single electric grid optimally combining wind, solar, hydroelectric, and geothermal power, she says that it would be more economical, in the near future at least, to burn some natural gas as part of that mix. A shift to renewable energy is already under way in the United States. In , renewables passed nuclear power in the amount of electricity generated.
In addition, society is on the verge of benefiting from new kinds of efficiency gains. Computing advances, for example, could enable real-time modulation of supply and demand: imagine a hot summer day when air conditioning causes the demand for electricity to spike—and the batteries in electric cars provide a buffer during peak power use.
Read about two alumni applying these technologies with utilities today. View the discussion thread. Isaac Kohane studies exceptional responders. Elizabeth Hinton Photograph by Stu Rosner. John Rawls and the remaking of political philosophy. Energy Information Administration. Source: data from Lawrence Livermore National Laboratory. ON, the largest utility, which owns Grafenrheinfeld and many other plants, declared a loss of more than three billion euros last year. ON is splitting into two companies, one devoted to coal, gas, and nuclear, the other to renewables.
The CEO, once a critic of the energiewende, is going with the renewables. In a trench that covers 11 square miles and is more than feet deep, 13 gargantuan digging machines work in synchrony—moving the trench through the landscape, exposing and removing the lignite seam, and dumping the overburden behind them so the land can be replanted.
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On the same rebuilt hill stands a memorial to Wolkenberg, a village consumed by the mine in the s. Boulders mark the spots where the church and other buildings once stood.
Energy Revolution: The Physics and Promise of Efficient Technology | iCons Program
It was a gorgeous spring day; from Wolkenberg, the only cloud we could see was the lazily billowing steam plume from the 1. Even with the looming shutdown of more nuclear reactors, Germany has too much generating capacity. Vattenfall, however, plans to sell its lignite business, if it can find a buyer, so it can focus on renewables.
Last year the amount of new solar fell to around 1. At the end of April, Vattenfall formally inaugurated its first German North Sea wind park, an turbine project called DanTysk that lies some 50 miles offshore.
Energy Revolution : The Physics and the Promise of Efficient Technology (Electricity From the Sun)
The ceremony in a Hamburg ballroom was a happy occasion for the city of Munich too. As a result Munich now produces enough renewable electricity to supply its households, subway, and tram lines. By it plans to meet all of its demand with renewables. In part because it has retained a lot of heavy industry, Germany has some of the highest per capita carbon emissions in western Europe. Its goal for is to cut them by 40 percent from levels.
As of last year, it had achieved 27 percent. Last spring Gabriel proposed a special emissions levy on old, inefficient coal plants; he soon had 15, miners and power plant workers, encouraged by their employers, demonstrating outside his ministry. In July the government backed down. Instead of taxing the utilities, it said it would pay them to shut down a few coal plants—achieving only half the planned emissions savings. For the energiewende to succeed, Germany will have to do much more. It will have to get off gasoline and diesel too.
Rolf Disch in Freiburg is one of many architects who have built houses and buildings that consume almost no net energy or produce a surplus. But Germany is not putting up many new buildings. A lot is being done, but not enough. All over Germany, old buildings are being wrapped in six inches of foam insulation and refitted with modern windows. Low-interest loans from the bank that helped rebuild the war-torn west with Marshall Plan funds pay for many projects.
Just one percent of the stock is being renovated every year, though. For all buildings to be nearly climate neutral by —the official goal—the rate would need to double at least. Once, Sandrock said, the government floated the idea of requiring homeowners to renovate. The public outcry shot that trial balloon down. With all the parties in Germany in agreement, Rosenkranz said, the energiewende felt like that. Economic interests are clashing now. Some Germans say it might take another catastrophe like Fukushima to catalyze a fresh burst of progress. What can we learn from them?
But we can be inspired to think that the energiewende might be possible for other countries too. In a recent essay William Nordhaus, a Yale economist who has spent decades studying the problem of addressing climate change, identified what he considers its essence: free riders.
While most countries have been free riders, Germany has behaved differently: It has ridden out ahead.
And in so doing, it has made the journey easier for the rest of us. Read Caption. Wind turbines surround a coal-fired power plant near Garzweiler in western Germany. By Robert Kunzig. Photographs by Luca Locatelli. This story appears in the November issue of National Geographic magazine.
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Pull Quote What makes Germany so important, however, is the question of whether it can lead the retreat from fossil fuels. Workers have been taking apart this Soviet-era nuclear power plant, near Greifswald in eastern Germany, since , cleaning radioactive surfaces with steel grit so the metal can be recycled.
Germany plans to shut all its reactors by A nuclear reactor at Kalkar was finished just before the explosion at Chernobyl, Ukraine—and never used. The support is rooted in an eco-friendly culture, a collective desire to abandon nuclear energy, and laws that allow citizens to profit from selling their energy to the grid. Solar and Wind Energy in Germany. Installed capacity by postal code area, megawatts per square mile.
Wind-dominant region. Solar-dominant region. Green Day. On July 25, , it was very windy in the north and sunny in the south. After the disaster in Fukushima, Japan, in , Germany vowed to quickly abandon nuclear energy. Of 17 operable reactors, nine have since been shuttered. The rest are set to close by Offshore Promise. Germany has invested heavily in energy generated by offshore wind and expects one-third of its future wind energy to come from offshore farms.
To bring renewable power from the windy north to the heavily industrialized south, government and utilities have proposed at least two high-voltage, direct current HVDC power lines. Kirkus Reviews Issue: Dec. Email address:. Please provide an email address. Categories of Interest: Select All. Current Affairs. Historical Fiction.
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