When Tom Van Flandern bought a tiny electric "Citicar" during the gasoline crunch of 1974 and began commuting to work in it from his Bethesda home, it seemed a little bit like driving "a souped-up golf cart."

Six years later, although the electric car industry is still in its infancy, the U.S. secretary of energy drives a stylish and powerful electric Omni around Washington, and businesses and government agencies across the country are ordering electric vehicles by the hundreds.

About 2,000 electric vehicles are in use in the United States today, and the federal Department of Energy projects that by the year 2000 there will be 9 million -- 5 percent of the U.S. vehicle fleet then.

Today's electrics still run on cumbersome versions of the basic lead-acid car battery and have a range of about 40 miles -- a distinct disadvantage -- but scientific advances may improve that.

Gulf & Western Industries Inc. announced on Thursday that it had developed a battery that it said will power an electric car 200 miles on a single charge.

Although scientists say there are still significant problems to be overcome before the Gulf & Western battery is ready for widespread use, the company's announcement -- plus a General Motors plan to produce electrics by 1985 -- has fired enthusiasm for electric cars.

"Americans will buy them," said Van Flandern, who still drives his Citicar -- a tiny red contraption -- to and from the U.S. Naval Observatory, where he is an astronomer. "When they get a few more improvements, there will be a whole lot of people who will buy them."

That is the hope of Department of Energy officials, whose goal is to spur development of electric vehicles with a variety of incentives and cost-sharing programs so the country will have something to fall back on in case of another gasoline shortage.

"We're not trying to replace the gasoline vehicle. We just want to provide an alternative," said Anthony H. Ewing, chief of the demonstration and incentives branch in DOE's electric and hybrid car division.

"Suddenly there's a lot of interest in electric because of the price at the [gasoline] pump," said Paul Brown, chief of the department's electric and hybrid car division. "There are so many things an electric car can do. You can't tow a boat trailer, but you can do 80 percent of your second-car driving with one. You can use it on a lot of in-town missions."

Another big advantage of electrics, according to the experts: they are pollution-free, assuming electric power plants are held to clean-air standards, and, although they take hours to charge, this can be done at night when the nation's power plants have plenty of spare generating capacity.

Van Flandern's Citicar cost only $2,500, but electric cars and vans -- converted Omnis, Pacers, Rabbits and other vehicles -- now sell for $7,000 to $12,000, and even more.

But because the Energy Department will foot the bill when a company purchases electric vehicles, firms such as American Telephone and Telegraph, Consolidated Edison, General Telephone and Electronics and the U.S. Postal Service are buying them to use as repair and delivery trucks, messenger vehicles and security runabouts.

"We buy them because we have to look for some way to get out from under the petroleum crunch," said Donn Crane, director of fleet management for the U.S. Postal Service, which has 383 electric delivery trucks and has just ordered 375 more.

At the Falls Church Post Office, where 10 of the vehicles are being used, there have been problems.

"One man had a hill on his route and every day he had problems [getting up it]," said Gene Merkert, manager of customer services at Falls Church. "You can't put [electrics] on long routes, either."

"You want to take 'em away?" postman Gary Wamsley said to a visiting reporter. "Good."

Clifford Hayden, energy director for General Telephone and Electronics, said the firm has 75 electric vehicles operating in Florida, Long Beach and Honolulu.

"We're putting them in normal operations and missions and not making any compromises other than range," Hayden said. He said that the electrics are used on the shorter repair routes because of doubts about their ability to go long distances.

John McDougall of AT&T said the company's 20 electric repair vans average about 15 miles a day, and sometimes the repair crews have to come in early when their vans run low on electricity.

"We're not getting as much [mileage] as we would like to get out of them," McDougall said. Still, he will order more.

New York State's Energy Research and Development Authority carefully studied available electric vehicles before deciding to order several dozen converted VW Rabbits at more than $17,000 each. Among other things, they will be driven by government nurses in Westchester County.

Long Island Lighting, a utility company, is using 30 electric vans and has 19 more on order.

The company found its electric vehicles require less maintenance and are cheaper than gasoline-powered cars to operate on a cost-per-mile basis excluding the cost of replacing batteries.

Long Island Lighting has sold about 20 electric cars to other individuals and firms, acting as a broker between the manufacturers and buyers. A company spokesman said there is such enthusiasm for the vehicles that the firm could easily sell 1,000 if they were available.

In return for financial help from the Energy Department in buying the vehicles, companies and organizations like those above maintain elaborate records on the vehicles' performance for the federal agency.

Meanwhile, the federal agency is helping firms with loan guarantees and other incentives to develop advanced models of electric vehicles that will come into being during the next decades.

The most critical technological problem for electric vehicles is their batteries. Even the sporty Omni driven by Secretary of Energy Charles Duncan is still powered by zippy versions of the basic lead-acid battery that powers golf carts.

Duncan's Omni can hit 55 mph on the highway, but its range is limited to about 40 miles. Then it must be recharged, a process that takes several hours.

Several firms are studying ways to improve the lead-acid battery, and others are working on more powerful batteries made of nickel, iron and zinc.

Gulf & Western's new battery is made of zinc and chlorine. A company spokesman said it would allow four people in a VW Rabbit to drive 150 miles at 55 mph before recharging the batteries.

That's a significant improvement: a Rabbit with four passengers and powered by today's batteries could travel only about 45 miles, and as a practical matter less, at a highway speed of 55 mph, according to the Energy Department.

The DOE's Brown said the Gulf & Western battery is about 15 percent heavier than other types -- a draw-back -- but delivers about 40 percent more power per pound.

There are other problems with the Gulf & Western battery, too.

"In terms of acceleration, zinc-chlorine is no better than the other [batteries], maybe not as good," said Chinton Christianson, deputy project manager for near-term electric vehicle batteries at the Argonne National Laboratory, which is testing batteries for the Energy Department.

Conrad Weinlein, manager of advanced development engineering for Globe-Union Inc., which develops batteries, said one drawback of the Gulf & Western battery is that "it requires a refrigeration system for charging. It's off-board so you can't charge except at home. Otherwise, it looks quite promising."

A senior industry scientist who has studied test results of the Gulf & Western battery, and who asked not to be identified, said it appears that the battery will provide adequate acceleration and may be discharged and charged 1,000 times or more -- more than twice the number of times a lead-acid battery may be used.

This increased "cycle life" is important because it costs more than $1,000 to replace the 18 to 20 batteries in an electric vehicle, and at present they last only about two years.

The Gulf & Western battery in its current state has a corrosion problem with its complex system of pumps and valves. This complexity, along with the bigger, bulkier size of the battery, present engineering problems that can be solved but may add to the cost, the senior industry scientist said.