A 50-cents-a-gallon tax on gasoline is independent presidential candidate John B. Anderson's most famous campaign idea. Fittingly, then, the gasoline tax is reflected both in letter and spirit in the energy portions of Anderson's "National Unity Campaign" platform.

Anderson's theory is that adding a new tax to the already rapidly inflating price of gasoline will discourage gasoline use and thus reduce dependence on foreign oil supplies. And this concept -- reducing energy consumption through price mechanisms -- is central to the energy plank in the platform Anderson made public last weekend.

The platforms of the Democratic and Republican parties also emphasized reducing consumption as a means of meeting the energy crisis. But Anderson's places more stress than either of the major party platforms on the subject of conservation. Anderson's document discusses the subject at greater length and offers more specific ideas to aid conservation than either of the other two platforms.

Anderson says he will "firmly support" a total decontrol of oil and gas prices. "Letting prices rise is the most efficient way to exploit our conservation potential," the platform says. In a similar vein, he proposes new formulas for pricing electricity to reduce its use and spread consumption more evenly around the clock.

The major party platforms agree with these proposals. But Anderson is alone in his plan to add a 50-cent tax to the decontrolled price of gasoline.

"A 50 cent per gallon tax would achieve a reduction in gas consumption of as much as 700,000 barrels per day in the short run and over 1 million barrels per day in the longer term," the platform asserts. The United States is currently importing about 6.5 million barrels of oil per day.

Anderson proposes to use the $50 billion his gasoline tax would raise each year to offset increases in the Social Security tax.

The Anderson platform also calls for tougher mileage standards to be imposed so that the cars Americans drive will use less gasoline per mile. The document calls for extending fuel economy standards to light-duty and pickup trucks, which are currently exempted from the mileage rules. Anderson also says he would "enforce strict adherence to the 55-mile-per-hour speed limit," a pledge that aligns him with the Democrats but is directly oppposed to the Republican plan to eliminate the 55 mph limit.

Like the other platforms, Anderson's also discusses the need for conservation in homes and industry. But while the Democratic platform calls for "massive" federal grants to help people save energy, Anderson would try to achieve that purpose through tax incentives and loans, many of which he would like to see provided by the utilities.

On the other hand, Anderson would continue some government energy grants, including assistance to help the poor pay their heat and light bills. He also proposes a $4 billion federal trust fund for mass transit.

Anderson puts considerably less emphasis than the Republican Party did on federal efforts to encourage domestic oil production, but he does suggest some steps to do that. The Anderson platform also calls for stepped-up completion of the national petroleum reserve. "A regional reserve for the Northeast, an area particularly dependent on imported oil, should be constructed," the platform adds.

As for alternative fuels, Anderson's platform is hot on coal and lukewarm on nuclear power. As in many other areas of policy, Anderson calls for tax incentives to spur greater production of coal and more conversion from petroleum fuels to that alternative.

Through most of his congressional career, Anderson, a Republican from Illionois, was a supporter of nuclear power and its development. But his mind seems to have changed in the past year, and the platform reflects his new hesitancy.

It says that the Nuclear Regulatory Commission "should be barred from issuing new operating licenses [for nuclear electric generating stations] unless the commission certifies that the stringent safeguards adopted since Three Mile Island have been incorporated into the plant design, operating procedures and emergency plans." Further, Anderson calls for a moratorium on new construction of nuclear plants until a location for permanent disposal of the plants' nuclear waste has been found. This would effectively prevent issuance of any new construction permits.

Like the Democratic and Republican platforms, Anderson also talks about development of more exotic energy sources, such as wind, fusion and the heat in the ocean. The platform also says, in the energy chapter, that "we need to revitalize our space program" -- because it is a good place for energy innovation.

The Anderson platform goes on to say that the need for new energy development does not justify revamping environmental protections established in the past decade.

"The nation's environmental standards were enacted to protect the health and safety of the American people and to ensure the quality of our lives and the lives of our children," the platform says.

"We will exert our best efforts," it adds, "to meet our national committment of protecting our environment. We will not relax these standards."