THE HOUSE Ways and Means Committee will soon have an opportunity to kill the president's plan for an energy trust fund. It is an opportunity to be seized. The energy trust fund is a dangerously flawed concept, and no amount of tinkering can make it right.

When President Carter decided to decontrol oil prices, he saw the need for a tax to return to the public some of the gigantic increases in revenues to the oil producers. So far so good. But then he adopted the idea of putting all of those revenues into what he called the Energy Security Fund. Out of it, he proposed to pay a little for aid to the poor, a little more for public transit, and quite a lot for the development of new energy supplies.

The big flaw is that no real relationship exists between those needs and the amounts of money flowing into the fund. If the oil taxes should return less than estimated, the shortfall would restrict the subsidies to the poor, the transit systems and new energy technologies. But it is infinitely more likely, almost certain, that the income to the fund would be far greater than the administration's estimates. The administration's figures are based on oil price forecasts that are already demonstrated to be vastly too low. The trust fund would be inundated with money, creating a strong temptation to expand those subsidies beyond all justification.

Helping the poor and mass transit and new energy technologies are all worthy and proper uses of tax money. But it is the responsibility of Congress to set those appropriations in terms of the needs that they meet, rather than leaving them up to the blind workings of a trust-fund formula.

Mr. Carter adopted the trust fund because he expected it to strengthen his tax plan in Congress. But it is a liability that drags on the tax bill. If the tax bill continues to lose momentum, the whole oil price decontrol plan will fall into great jeopardy.The Ways and Means Committee will do a service by dumping the trust fund overboard, to improve the chance of survival for those parts of the plan that should be saved.