THE NEXT STAGE of this country's energy policy rests in the mass of legislation now grinding its way through the final stages of enactment. It's scattered through three bills, in three different Senate-House conferences. A brief inventory is useful: these bills vary greatly in quality and urgency.

At the top of the list is the bill to speed up the production of synthetic fuels -- gas and oil, for example, manufactured from coal. It is time to get going with prototype plants to begin testing a wide range of these technologies at full industrial scale. A few plants are already under construction, but there's much more to be done.

The House passed its original synthetics bill, in loose and hasty form, 14 pages long, last June when the gasoline lines were at their worst. The Senate's subsequent version runs to 340 pages and includes a great variety of odds and ends -- including, unfortunately, a wildly controversial gasohol amendment that threatens to tie up the bill indefinitely.

Experimenting with gasohol -- 90 percent gasoline, 10 percent alcohol -- is reasonable enough on a modest scale. But the Senate bill commits the federal government to it in a very big way indeed. It sets a goal of replacing the country's entire gasoline supply with gasohol by 1990. That idea comes, needless to say, from farm interests who see it as a good way to raise grain prices. That means, inevitably, raising food prices. If you think that food prices are not yet rising fast enough, you will doubtless support the Senate's gasohol amendment. Otherwise, you will probably conclude that the House conferees ought to cut it way or, even better, drop it from this bill altogether and insist on handling it separately.

The second of these energy bills is the windfall tax on crude oil -- a subject that we have discussed at some length in this space. In brief, the House bill is in every respect superior to the Senate bill, with its low rates and egregious exemptions.

The third bill -- not so urgent, this one -- would set up an Energy Mobilization Board. Some of the environmental laws sometimes get in the way of large industrial projects like pipelines and synthetic fuel plants. The conference is debating the board's power to cut corners and waive certain of those laws. The Senate's more limited version is preferable. But the whole principle here is a bad one.It is wrong to leave laws in force for most people while lifting them for a few.

You will note that none of these bills would increase fuel supplies very soon or diminish consumption much. None of them speaks to that terrible impending question about a sudden disruption in the flow of oil from the Persian Gulf. All this legislation assumes that oil supplies will keep getting tighter, as they will. But it also assumes that the process will be gradual. Is that a safe assumption? Perhaps it is not reasonable to expect Congress, or any government, to try to prepare for an utterly unpredictable oil shortage that could be of almost any magnitude, starting at any time. Perhaps the current bills are the best effort that anyone expect. But when you hear people talk about national energy policy, it's useful to remember that one large unstated element in it is the American custom of trusting to luck for the next few years.