Americans waste energy all the time.

Lone commuters look themselves in 3,000-pound gasoline guzzlers driving to work and back.

Precious heat seeps out of poorly insulated homes while the gas yard-lamps burns all day.

A factory's boilers work up a head of steam to produce goods while a nearby electric plant does the same thing to produce electricity for the same factory.

Apartments are brightly lit, needlessly, round the clock.

Warm water is unnecessarily used for the rinse cycles of clothes washers.

Wasted energy may account for 30 or even 50, per cent of all the energy consumed in the United States. In 1975, this country wasted more fossil fuel than was used by two-thirds of the world's population, according to Denis Hayes of the Worldwatch Institute, a Washington-based nonprofit research organization.

West Germany, with a standard of living similar to ours, uses only half as much energy per person, according to the Federal Energy Administration.

"There is nothing that we do that's as efficient as it could be," FEA's John G. Muller says of a nation that prides itself on its technology, its living standard and its can-do attitude. "We could cut waste tremendously without changing the way we live. If you change, you save even more."

The watchword of President Carter's fireside remarks on energy is conservation, which itself is the most readily available source of new energy supplies because energy saved is energy produced.

Conservation means getting more out of the energy we must consume and eliminating consumption that isn't essential. Some examples: doubling up in cars or switching to mass transit, and buying leaner cars that go farther on a gallon. Generating electricity for factories with the same steam used for production. Re-insulating the house and turning off the yard-lamps (13 of them can heat two houses). Separating the electricity bill from rent, because direct payment by the tenant reduces consumption by 25 per cent. Rinsing laundry - or doing the whole wash - in cold water.

How have we become such wastrels?

"It's just been too cheap," FEA's Muller says of our once seemingly endless supply of energy.

"The United States matured in an era of abundant fuel and declining real energy prices," says Hayes. Cheap energy "was substtituted for all other factors of production . . . "

"The most important variable, affecting energy use and energy efficiency is the relative price of energy . . . to other resources," according to a Science magazine article that concluded that Sweden, too, has a living standard close to ours but uses far less energy.

"High national gasoline prices and/or taxes have promoted the manufacture and purchase of relatively efficient autos, notably in Western Europe, and low gasoline prices&taxes have led to large inefficient autos, notably in the United States and Canada," says the International Energy Agency.

A survey by the IEA - 18 oil-consuming nations' answer to the oil producers' cartel - reported last year that, despite the price rises of recent years, the United States still has the cheapest gasoline and natural gas.

The single largest use of energy in the United States is the production of steam industry. Muller says that for years industry enhanced profits by wasting cheap energy rather than installing generators to produce electricity with its own steam.

With our energy demand growing at 2.5 per cent a year, according to FEA's 1977 National Energy Outlook, and our dependence on foreign oil still growing, there is widespread agreement now on the need for conservation. The federal Energy Research and Development Administration has revised its thinking to recognize the increased importance of conservation as a source of more energy.

There is disagreement, however, on how to stimulate conservation, how much energy can be saved and what impact it may have on the economy.

A Chase Manhattan Bank report says: "An analysis of the uses of energy reveals little scope for major reductions without harm to the nation's economy and its standard of living. The great bulk of energy is utilized for essential purposes . . . " Fifty per cent of U.S. energy consumption heats houses, generates steam for industry, heats industry amd powers automobiles.

But in a report last year, the FEA found West Germany using far less energy to do those same things - one-fourth as much per person for transportation, one half as much for residential heating (adjusted for climate). The United States uses 40 per cent more energy for the equivalent industrial output.

The FEA concluded: "It may be possible to achieve a substantial reduction in the rate of growth of energy consumption in the United States without reducing the standard of living and economic growth."

Writing in Science magazine, University of California researchers Lee Schipper and Allan J. Lichtenberg said the primary reason Sweden burns less energy than the United States is not that it has learned to do without but that it has learned to do better. Since fuel costs more, it is used more wisely. Schipper and Lichtenberg conclude that if Americans drove lighter and more efficient cars, erected better buildings and used industrial steam more efficiently, the United States could perhaps cut energy consumption 30 per cent.

It could be cut if Americans would not throw away used motor oil rather than recycle it for lubricants, if they would not overpackage food at such a rate that production of packing increases faster than consumption of food; if gas pilot lights did not burn endlessly when most could be replaced by electrical igniters; if houses were not under-insulated; if we did not use 20 times as much electricity to produce a pound of aluminium from raw material as we would to produce a pound from recycling.

"All of us must learn to waste less energy," the President said in his fireside remarks. "There is no energy policy we can develop that would do more good than voluntary conservation."

However, in its report last year, the International Energy Association said, "The United States conservation program . . . is severely hampered by oil and gas prices controlled below world marked prices and by very low taxes on all fuels."

"We've been living on our (energy) inheritance, not on our income," says FEA's conservation expert, Muller. "And we're spending it faster than we're building up on our annuity. Depending on what sacrifices we make, we can reduce it any amount."