2012年3月26日星期一

forwarded: How to Prevent Environmental and Economic collapse

World on the Edge: How to Prevent Environmental and Economic Collapse

Lester R. Brown

Chapter 8. Building an Energy-Efficient Economy

Advancing technologies offer the world a greater potential for cutting energy use today than at any time in history. For example, during much of the last century nearly all the household light bulbs on the market were inefficient incandescents. But today people can also buy compact fluorescent lamps (CFLs) that use only one fourth as much electricity. And the light-emitting diodes (LEDs) now coming to market use even less. 1

A similar situation exists with cars. During the century since the automobile appeared, an internal combustion engine was the only option. Now we can buy plug-in hybrids and all-electric cars that run largely or entirely on electricity. And since an electric motor is over three times as efficient as an internal combustion engine, there is an unprecedented potential for reducing energy use in the transport sector. 2

Beyond energy-saving technologies, vast amounts of energy can be saved by restructuring key sectors of the economy. Designing cities for people, not for cars, is a great place to begin. And if we can move beyond the throwaway society, reusing and recycling almost everything, imagine how much material and energy we can save.

One of the quickest ways to cut carbon emissions and save money is simply to change light bulbs. Replacing inefficient incandescent bulbs with CFLs can reduce the electricity used for lighting by three fourths. And since they last up to 10 times as long, each standard CFL will cut electricity bills by roughly $40 over its lifetime. 3

The world has reached a tipping point in shifting to compact fluorescents, as many countries phase out incandescents. But even before the transition is complete, the shift to LEDs is under way. Now the world’s most advanced lighting technology, the LED uses even less energy than a CFL and up to 85 percent less than an incandescent. And LEDs offer another strong economic advantage—longevity. An LED installed when a child is born is likely to still be working when the youngster graduates from college. 4

With costs falling fast, LEDs are quickly taking over several niche markets, such as traffic lights. In the United States, almost 70 percent of traffic lights have been converted to LEDs, while the figure is still less than 20 percent in Europe. New York City has changed all its traffic lights to LEDs, cutting the annual bill for power and maintenance by $6 million. 5

For the far more numerous street lights, the potential savings are even greater. In 2009, Los Angeles Mayor Antonio Villaraigosa said the city would replace its 140,000 street lights with LEDs, saving taxpayers $48 million over seven years. With replacement well along, the electricity bill for street lights was down 55 percent as of mid-2010. 6

Leading bulb manufacturers such as Phillips and GE are currently selling their lower-wattage LEDs for $20. As prices fall, Zia Eftekhar, head of Phillips lighting in North America, expects LEDs to take more than 50 percent of the North American and European markets by 2015 and 80 percent by 2020. In 2009, China and Taiwan joined forces in manufacturing LEDs to compete more effectively with Japan (currently the world leader), South Korea, Germany, and the United States. 7

Energy can also be saved by using motion sensors that turn lights off in unoccupied spaces. Automatic dimmers can reduce the intensity of interior lighting when sunlight is bright. In fact, LEDs combined with these “smart” lighting technologies can cut electricity bills by 90 percent compared with incandescents. 8

All told, shifting to CFLs in homes, to the most advanced linear fluorescents in office buildings, commercial outlets, and factories, and to LEDs for traffic lights would cut the world share of electricity used for lighting from 19 to 7 percent. This would save enough electricity to close 705 of the world’s 2,800 coal-fired plants. If the world turns heavily to LEDs for lighting by 2020, as now seems likely, the savings would be even greater. 9

A similar range of efficiencies is available for many household appliances. Although the U.S. Congress has been passing legislation since 1975 to raise efficiency for 22 broad categories of household and industrial appliances, from dishwashers to electric motors, the U.S. Department of Energy (DOE) had failed to write the standards needed to implement the legislation. To remedy this, just days after taking office President Barack Obama ordered DOE to write the needed regulations and thus tap this reservoir of efficiency. In September 2010, DOE announced that new efficiency standards for more than 20 household and commercial products had been finalized since January 2009, noting that this “will cumulatively save consumers between $250 billion and $300 billion through 2030.” 10

A more recent efficiency challenge is presented by large flat-screen televisions. The screens now on the market use much more electricity than traditional cathode ray tube televisions—indeed, nearly four times as much if they are large-screen plasma models. Setting the U.S. pace in this area, as in so many others, California is requiring that all new televisions draw one third less electricity than current sets do by 2011 and 49 percent less by 2013.. Because the California market is so large, it could very likely force the industry to meet this standard nationwide. 11

The big appliance efficiency challenge is China, where modern appliance ownership in cities today is similar to that in industrial countries. For every 100 urban households there are 133 color TV sets, 95 washing machines, and 100 room air conditioners. This phenomenal growth, with little attention to efficiency, helped raise China’s electricity use a staggering 11-fold from 1980 to 2007. 12

Along with the United States and China, the European Union has the other major concentration of home appliances. Greenpeace notes that even though Europeans on average use half as much electricity as Americans do, they still have a large reduction potential. A refrigerator in Europe uses scarcely half as much electricity as one in the United States, for example, but the most efficient refrigerators on the market today use only one fourth as much electricity as the average refrigerator in Europe, suggesting a huge potential for cutting electricity use further everywhere. 13

Technological progress keeps raising the potential for efficiency gains. Japan’s Top Runner Program is the world’s most dynamic system for upgrading appliance efficiency standards. In this system, the most efficient appliances marketed today set the standard for those sold tomorrow. Within a decade, Japan raised efficiency standards for individual appliances by anywhere from 15 to 83 percent. This ongoing process continually exploits advances in efficiency technologies. 14

Although appliances account for a significant share of electricity use in buildings, heating and cooling require more energy in total. But buildings often get short shrift in efficiency planning, even though the sector is the leading source of carbon emissions, eclipsing transportation. Because buildings last for 50¬–100 years or longer, it is often assumed that cutting carbon emissions in this sector is a long-term process. But that is not necessarily the case. An energy retrofit of an older inefficient building can cut energy bills by 20–50 percent or more. The next step, shifting entirely to renewable sources of electricity to heat, cool, and light the building, completes the job. Presto! A zero-carbon building. 15