Seven Ways to Save the WorldForget the old idea that conserving energy is a form. of self-

Seven Ways to Save the World

Forget the old idea that conserving energy is a form. of self-denial -- riding bicycles, dimming the lights, and taking fewer showers. These days conservation is all about efficiency: getting the same -- or better -- results from just a fraction of the energy. When a slump in business travel forced Ulrich Romer to cut costs at his family-owned hotel in Germany, he replaced hundreds of the hotel's wasteful light bulbs, getting the same light for 80 percent less power. He bought a new water boiler with a digitally controlled pump, and wrapped insulation around the pipes. Spending about ？100,000 on these and other improvements, he slashed his ？90,000 fuel and power bill by ？60,000 As a bonus, the hotel's lower energy needs have reduced its annual carbon emissions by more than 200 metric tons. "For us, saving energy has been very, very profitable," he says. "And most importantly, we're not giving up a single comfort for our guests."

Efficiency is also a great way to lower carbon emissions and help slow global warming. But the best argument for efficiency is its cost -- or, more precisely, its profitability. That's because quickly growing energy demand requires immense investment in new supply, not to mention the drain of rising energy prices.

No wonder efficiency has moved to the top of the political agenda. On Jan. 10, the European Union unveiled a plan to cut energy use across the continent by 20 percent by 2020. Last March, China imposed a 20 percent increase in energy efficiency by 2020. Even George W. Bush, the Texas oilman, is expected to talk about energy conservation in his State of the Union speech this week.

The good news is that the world is full of proven, cheap ways to save energy. Here are the seven that could have the biggest impact:

Insulate

Space heating and cooling eats up 36 percent of all the world's energy. There's virtually no limit to how much of that can be saved, as prototype "zero-energy homes" in Switzerland and Germany have shown. There's been a surge in new ways of keeping heat in and cold out (or vice versa). The most advanced insulation follows the law of increasing returns: if you add enough, you can scale down or even eliminate heating and air-conditioning equipment, lowering costs even before you start saving on utility bills. Studies have shown that green workplaces (ones that don't constantly need to have the heat or air-conditioner running) have higher worker productivity and lower sick rates.

Change Bulbs

Lighting eats up 20 percent of the world's electricity, or the equivalent of roughly 600,000 tons of coal a day. Forty percent of that powers old-fashioned incandescent light bulbs -- a 19th-century technology that wastes most of the power it consumes on unwanted heat.

Compact fluorescent lamps, or CFLs, not only use 75 to 80 percent leas electricity than incandescent bulbs to generate the same amount of light, but they also last 10 times longer, Phasing old bulbs out by 2030 would save the output of 650 power plants and avoid the release of 700 million tons of carbon into the atmosphere each year.

Comfort Zone

Water boilers, space heaters and air conditioners have been notoriously inefficient. The heat pump has altered that equation. It removes heat from the air outside or the ground below and uses it to supply heat to a building or its water supply. In the summer, the system can be reversed to cool buildings as well.

Most new residential buildings in Sweden are already heated with ground-source heat pumps. Such systems consume almost no conventional fuel at all. Several countries have used subsidies to jumpstart the market, including Japan, where almost 1 million heat pumps have been installed in the past two years to heat water for showers and hot tubs.

Remake Factories

From steel mills to paper f

A．Raising efficiency.

B．Cutting unnecessary costs.

C．Finding alternative resources.

D．Sacrificing some personal comforts.