Many tried, but none succeeded. Now one hope remains.

President Carter tried to persuade the American people that the oil shortage is real. He told us again and again that our dependence on foreign sources is real. He warned that the price we pay is high in terms of dollars and ever higher in terms of long-range damage to our economy.

And recent events have made it clear that even when a nation is willing to pay a high price now, and more later, it has no assurance that its oil supplies will not be interrupted without notice.

Dozens of government officials echoed the prisident's warnings and pleas for conservation. Hundreds of oil industry experts told us the same things. "Opinion molders" solemnly agreed, and joined in preaching conservation.

But very few who heard the message acted upon it. Too few did to little.

Today, however, there is reason to hope that Providence has sent us a lower-case savior -- a man who can make us understand the situation clearly and rally us to the common cause of survival, That man is Ayatollah Ruhollah Khomeini.

Some demonstrators and counter-demonstrators have been saying harsh things about the ayatollah, but I think we owe him a great debt of gratitude. He has finally brought home to millions of Americans the realization that we cannot end our constant fear of being cut off from foreign oil until we become self-sufficient.

A Washington Post editorial pointed out on Saturday that this country's use of oil and its derivatives figures out to 10 gallons per household per day. However, if we were to reduce our use of oil by just five pints a day per household, we would change a seller's market to a buyer's market. We would "leave the various ayatollahs and mullahs to take their oil elsewhere."

Ther would be a better balance between supply and demand. We would end the present "standing invitation to the exporting countries to keep raising prices, to play favorites among customers and to demand intolerable political concessions."

If and when demand for oil diminishes, the oil exporting nations "would have to begin allocating production cuts among themselves, an awkward and devisive process." How long could the OPEC monopoly survive under those conditions?

Five pints a day per household is all it would take. We could easily get a good part of that out of more prudent use of our automobiles.The rest could come from savings on winter heating and summer cooling. Industrial users and commercial plants could also make substantial contributions through better planning and the elimination of outright waste.

The Post editorial concluded with the words, "together, as a country, we drove ourselves into this mess. Any time we want to do it, we can walk out of it."

With the ayatollah's help, we may finally be sufficiently unified in our common defense to start walking. POSTSCRIPT

If you'd like examples of some of the hundreds of things we can do -- right now -- to cut our dependency on oil, yesterday's news supplied two good ones.

A dispatch that began on page 1 told about Vepco's two North Anna Nuclear plants. One, in operation for a year, produces enough electricity to light homes in an area the size of Wasington plus all its Northern Virginia suburbs. The other, its twin, has been ready to go into operation since June but has produced nothing because of a federal moratorium on all nuclear plants. b

The article posed the question, "What sense does a government policy make that lets one reactor operate at the North Anna plant and keeps an identical reactor sitting idle a few hundred feet away?" The answers that were supplied were, let us say, inadequate.

Immediately following that article on the two North Anna nuclear plants was a much shorter story about Vepco's new office building in Richmond.

The building gets most of its electricity from solar power, and uses manufactured energy only at night.

Imagine that! This was not another story about a building that is being planned to conserve energy. This was not a gee-whiz article in a weekly tabloid about what we may be able to do in the year 2000. This was a factual report of a finished building that is now in use -- and by an electric power company, at that.

More sophisticated and more widespread use of solar power may still be decades away. But some things can be done now. And we ought to be concentrating the full power of private ingenuity and governmental support on doing them.

The ayatollah demands it of us, and I certainly hope we won't let him down.