On the surface, it seemed just another example of the legislative language spoken so cryptically on Capitol Hll.

House and Senate Appropriations committees last year directed the Department of Energy to come up with a "national exemplar" solar energy project to be linked to an experiment to burn high-sulfur coal cleanly.

That vagueness could have meant a number of things, but it didn't. Without naming names, the committees intended, and DOE understood, that the project would go to Georgetown University here in Washington.

DOE is now reviewing Georgetown's proposal to build an intercultural center on the campus, using an array of rooftop photovoltaic cells to turns sun power into electricity for the building.

Georgetown's idea, which could cost DOE $8 million or more by some estimates, happens to fit the committee language precisely. GU already has a DOE-funded clean-coal experiment; it calls its program a "national exemplar."

University officials are reluctant to talk in detail about their proposal, but its progress so far is an example of one of the striking realities of the federal solar energy program.

Solar is the new glamor product in a federal dispensary whose traditional top-of-the-line items have been locks, dams, highways and public buidlings. Increasing research money gives solar a special place in the congressional sun.

"The interest is growing, especially in the appropriations area," said a high-level DOE official recently. "It's unmistakable. Part of it has to do with a member of Congress seeing the possibility of a nice solar project in his district."

The possibilities are clear. Solar research and demonstration funding has climbed from around$45 million in fiscal 1975 to about $600 million for this year. DOE has funded scores of solar projects in schools, factories, businesses.

"There are two forces at work," the DOE official continued. "One is the solar coalition in Congress, pushing for more development. The other is the overall state delegations, which see this as the new pork barrel."

Still a third force: universitites and colleges, companies and consultants eager to tap into the money barrel at DOE for help on research projects to harness the power of the sun.

In combination, as the cases of Georgetown and other costly solar projects show, these become powerful forces on decision-makers at DOE.

And while Georgetown officials downplay the idea, political support, carefully nurtured on Capitol Hill, has helped the university get its proposal as far as it has gone.

In fact, according to congressional committee aides, the university's lobbyists worked assiduously to plant the right seeds in the right places in Congress, briefing committee members, arguing their case.

Bennett Miller, head of a technical office at DOE that evaluates solar proposals, put it this way:

"Georgetown is talking to anyone who will listen, here and on the Hill. Hill staffers have called us to say GU is interested in being approved."

Even without that subtle prodding, Miller maintained, the university proposal shows "a vision that is commendable," although not necessarily a guarantee of approval.

Dean Price, the university architect, explained: "We have to convince people on the merits. In general, if you have a good idea it bleeds with merit."

GU's convincing was forceful enough that its idea somehow found its way into the appropriations language, although no one openly takes credit for putting it there.

"They had witnesses at our hearings for two or three years running," said Mel Greer, a committee assistant. "They gave a very attractive presentation. The committee looked at it and it just got in the final bill. The report language is tailored to the committee's wants. DOE did not ask for it."

Despite persistent committee reports to the contrary, House Speaker Thomas P. (Tip) O'Neill Jr. (D-Mass.), father of a Georgetown law graduate, denied that he or his staff played a role in promoting the school's proposal.

Beyond demonstrating a new technology on a large scale - the photovoltaic roof would be an acre and a half in size - Georgetown would stand to gain something else from approval of its proposal.

At federal expense, the coal-burning experiment and the companion solar project would pay a large share of the private university's energy costs in the future.

Although not quite like a dam or a highway in size, that sort of potential in the solar program flashes lights and rings bells in the minds of legislators eager to funnel federal assistance to home districts.

"I get paid to do technical evaluations," said DOE's Miller, "but I am not insulated from politics.. . . It is just in the nature of the business."

"Every member of Congress is concerned about the progress of projects in his district. We get 12 to 14 congressional letters a day. We're almost always bombarded. It's an everyday thing," Miller said.

Two of the more celebrated DOE solar project approvals, one in Mississippi and the other in Arkansas, happended to be in the home districts of legislators with powerful sway over DOE's budget.

In both cases, the project files indicate that DOE found major objections and raised major objections and raised major questions about the proposals.But in both cases, the agency worked overtime to find ways to approve them.

One was a $6 million grant for a photovoltaic and energy-storage project at Mississippi County Community College in Blytheville, Ark. DOE examiners had doubts about the proposal, but it had a strong patron - the late Sen. John L. McCellan (D-Ark.), who was chairman of Senate Appropriations.

The project was approved and it is now watched over by Sen. Dale Bumpers (D-Ark.), who according to an aide, "keeps riding herd on it. He was interested in this before McCellan died." Bumpers, too, is important to DOE. He is a member of the Senate Energy Committee, which oversees DOE activities.

The Mississippi project involved a $7.7 million solar heating and cooling grant , also using photovoltaic, for Northwest Mississippi Junior College at Senatobia, in the district of Rep. Jamie L. Whitten (D-Miss.), House Appropriations Committee chairman.

Whitteen at the time had not yet been named chairman, but DOE knew he soon would be. His name does not appear in the file documents, but DOE's sense of priority was clear - Washington was instructing its field office to move quickly.

"I feel very comfortable with that," said Miller. "The urgency was to get data. The project was not a good one when it came in, but it is now."

DOE officials advised the college at length how to improve its proposal, advice Miller said was "not unusual." He said, "hand-holding is okay, to help those with good ideas but who don't know how to be slick. It's wrong not to do that, or you end up approving only the glib proposals."

The college, facing severe cutbacks in natural gas, needed some new power source. Its solar project may show the way for new technology, but there's more to it than that:

Almost half of the federal grant will pay for steam pipes, hardly a new technology that cries for demonstration.