WILL an electric car help clear the world's dirtiest skies?The largest utility company in the United States has already bet $7 million on "yes." With the battle cry, "L.A. is going electric," the Los Angeles Department of Water and Power (DWP) unveiled an electric car here recently that officials say will be commercially viable by early 1993. A Swedish company known as CleanAir Transport plans to produce 1,000 of the two-door hatchbacks in 1993 and 30,000 by 1995. General Motors (GM), Chrysler, Ford, Nissan, and Toyota are among other companies developing protot ypes. The moves are more than just wishful thinking. To meet standards of 1990 amendments to the Clean Air Act, the California Air Resources Board has required manufacturers to build minimum numbers of zero-emission cars: 2 percent or 40,000 of new cars sold in California by 1998, 10 percent or 200,000 of all cars by 2003, and 17 percent by 2010. The move is being closely watched by the other, most-polluted cities mandated by the US Environmental Protection Agency to meet federal standards: New York, Baltimore , Chicago, Philadelphia, and Milwaukee. "The electric car has always been thought of as the ultimate solution from the standpoint of pollution abatement," says C. Kenneth Orski, president of Urban Mobility Corporation, a Washington, D.C., transportation consulting firm. "Now the regulatory mandate is pushing the fantasy towards reality." "This prototype represents a quantum leap," says Tim Little, executive director of the California Coalition for Clean Air. "Pollution activists have been screaming for them for years ... and this will be the first time they've ever been marketed for the masses." A ride in the pearl-colored prototype called the LA301 (see story below) feels like a conventional car with the quiet "whirr" of an electric golf cart. The 18 batteries that sit beneath the car's center floor drive a 57-horsepower motor. A seven-gallon gas tank powers an auxiliary ultra-low-emission engine, intended to augment electric power at speeds greater than 30 m.p.h. With four seats, two-speed automatic transmission, and conventional controls, dashboard, and interior, the car is expected to sell for $25,000. 'THE technical goal has been to overcome size, comfort, design, and range limitations that have always been associated with electric cars," says Lars Kyrklund, marketing director for CleanAir. International Automotive Design Ltd., a British company, was commissioned to do the design work. Innovations include specially developed "low rolling resistance" tires, an energy-absorbing, steel chassis, and an electronic power-train management system that coordinates two engines. Beneath the car's sporty, sloped hood is a three-pronged plug that will fit ordinary 110- and 220-volt outlets. One eight-hour electrical charge (cost: $1) will carry it 60 miles. Maximum speed is 75 m.p.h., and acceleration is 0-to-30 m.p.h. in seven seconds. To clear what designers feel is the largest hurdle of resistance to the car - consumer interest - the LA301 comes with power steering and brakes, electric windows, and a compact disc player as standard equipment. "We want to make Los Angeles the first 'EV friendly' city in the US," says Marvin Braude, the L.A. city councilman who began the initiative. GM is poised to release an electric car called "Impact" in the next three or four years. German firms Volkswagen and BMW have electric cars on the drawing board. And Amerigon, a Los Angeles company, is looking into retooling the dwindling aerospace industry to make L.A. an electric-car manufacturing center. The electric car "may not be the answer to all our transportation needs but will definitely meet the need for community and city-type driving," says Charles Hurst, a professor of mechanical engineering at Virginia Tech in Blacksburg, Va., a specialist in design alternatives to gas-powered cars. He sees the short-term use in institutional fleets such as post office vehicles. Professor Hurst, Mr. Orski, and others say the hurdles to public acceptance of electric cars are their greater purchase price, mechanical problems with batteries, slow acceleration in freeway traffic, and limited range. Strengths - besides eliminating exhaust - include cheaper fuel cost (about one-third that of gasoline per mile) and the opportunity electric cars provide to use low-cost energy during off-peak night hours. "Night charging will help power companies operate more efficiently and economically," says Don Siglar of the Los Angeles Department of Water and Power. How the cars affect pollution overall depends on the power plant providing the electricity: Natural gas, solar, or hydroelectric-generated electric power would mean cleaner air; increased demands on plants that generate electricity by burning coal would worsen smog, ozone, and atmospheric greenhouse-effect levels. Though critics wonder how cars can be recharged in ordinary parking lots and employee garages - and what happens when one needs recharging on a freeway - L.A. Water and Power officials say 90 percent of all trips taken by Los Angeles drivers fit within a 60-mile range. If higher amperage outlets could be developed, the car could charge in two hours, according to Kyrklund.