California has set a string of ambitious greenhouse gas-cutting goals in recent years, but whether they're attainable has been a subject of some skepticism.

One country we might look to for inspiration is Japan -- by some measures, the most energy-efficient country on the planet. The island nation has spent the last three decades on an obsessive quest to reduce its energy consumption.

Meet the Sakakis

Meet the Sakaki family: Dad Hiroshi, Mom Yukiko, and three-year-old daughter, May.

The Sakakis have an air conditioner but despite Tokyo's sweltering summer, they rarely use it. Their power strips have individual on/off switches so their appliances won't waste energy. They buy LED lights. Each night, they share bathwater, and their bathtub talks to them. It warns them when they're wasting energy.

The Sakakis aren't rabid environmentalists: They're typical Japanese. As a middle-class family living in Tokyo, they do whatever it takes to save energy. Why? The answer is in their hands, as they riffle through a stack of their monthly electricity bills.

"Six thousand to seven thousand yen, it's around a hundred U.S. dollars," said Hiroshi, looking at one bill.

And they spend a little more on natural gas. Energy costs twice as much as in the U.S., because Japan imports nearly all its fossil fuels.

Hard Lessons That Stuck

The lessons most Americans are starting to learn from rising oil prices are ones the Japanese have been practicing for the three decades, following the oil shocks of the 1970s. Economist Yukari Yamashita recalls that had Japan's economy on the brink of collapse.

"The prices of everything went up because of the oil crisis, so everybody was aware that we have to do something, otherwise our life won't be sustainable," said Yamashita.

Yamashita says it was as if the country were at war. The government held emergency meetings, quickly passing a series of conservation laws, forcing factories to replace old, inefficient boilers and assembly-line machinery with new energy-saving equipment. Rising energy taxes funded programs like low-interest loans for companies developing more energy-efficient solutions for industry.

As a result, Japan, the world's second-largest economy, now consumes one-half the energy -- per capita -- of the United States.

Industry Leads the Way

Nowhere have these energy saving measures had more impact than on Japan's industrial sector, where current energy use is on par with levels 40 years ago, despite dramatic economic growth since then.

By law, all manufacturers in Japan must make each of their factories one percent more energy efficient per year. This may not sound like much, but Shinya Okada, manager of a Daikin appliance plant outside of Kyoto, says it adds up over time.

"Each person who works in this factory has made small improvements to our products and our manufacturing process -- little tweaks, here and there," said Okada. "When you put it all together, it's meant huge savings in energy."

The government of Japan requires each factory to have at least one staff member who oversees energy efficiency. Daikin, one of the largest makers of air conditioners and refrigerators in Japan, has eight.

Another law, called the "top runner" program, requires Japanese appliance makers to ensure that each new model equals or surpasses the most efficient model available on the market at any given time.

Okada says companies like his weren't fond of this law when it was passed 12 years ago, "but now we find it valuable to compete with one another and develop technology not only to meet the strict government standards, but to cater to the needs of our customers."

Efficiency's Dividends

All this attention to efficiency has its downside. Daikin has tried several times to penetrate the American market, with little success. Remember the air conditioner the Sakaki family rarely uses? They have one in every room. AC units in Japan are made this way to save energy by cooling only the parts of the house that are in use. Daikin had a hard time selling this type of AC in the U.S., where the more inefficient central air is the norm.

Still, Japan's efficiency requirements have meant its companies lead the world in patents for green technology. This is a far cry from the country's industrial beginnings. Japan was a late industrial developer, opting to take time to learn from Western countries how to best develop the sector.

The common phrase used to be "America innovates, Japan imitates," but George Washington University Japan expert Llewelyn Hughes says the U.S. should turn this idea on its head.

"Perhaps an opportunity exists to go the other way. That is, to learn from Japan the lessons that have already been learned about how to better promote energy efficiency and also improve competitiveness in this particular sphere of the economy."

Japan, of course, is not perfect. While its industrial sector may be energy-efficient, critics say its housing sector could use a makeover. Many Japanese homes are poorly insulated, defeating the purpose of some of those efficient appliances. But economists say in the green-tech field, Japan is poised to dominate global markets.