The rapid global proliferation of computers, cell phones, plasma TVs, iPods and other energy-hungry devices is offsetting global gains in energy efficiency, according to a report by the International Energy Agency (IEA). Unless manufacturers, governments and consumers make a concerted effort to use far more efficient electronic equipment, energy consumption from such devices will double by 2022 and triple by 2030, the IEA said. Since 1990, household energy consumption has been rising worldwide at 3.4 percent a year, in large part because of the rapid spread and increasing sophistication of electronic devices. U.S. electricity consumption by television sets, for example, has tripled in the past 10 years, mainly because of the popularity of energy-sucking plasma TVs. The IEA report said that technologies already exist to improve energy efficiency of devices by 40 percent, but consumers and manufacturers often opt instead for more high-tech devices that consume large amounts of energy.