Cooling the $170,000 worth of snack foods - most of it soft-serve ice cream - sold every year at this remote, boat-only outpost takes a big refrigerator-freezer.

That's a lot of ice cream but nothing compared with the $2.7 million in annual gasoline commerce racked up at the dock. And not as much as the $258,000 in ice sales conducted at the Dangling Rope convenience store.This is boat central on Lake Powell, a floating little city at the end of the Earth that serves as a midjourney pit stop between the Wahweap Marina in Arizona and Bullfrog Marina some 80 miles north in Utah.

A dozen National Park Service employees maintain summertime quarters here alongside 32 employees of ARAMARK Leisure Services, which holds the retail franchise at Dangling Rope. All those workers, and all the 250,000 or so boaters who stop for refreshment and fuel from April to September, and everybody else who sets foot on the 365-day-a-year marina in the off-season, make - ultimately - for an enormous electricity bill.

This is why a consortium of government agencies and private interests have spent $1.5 million to import and install a solar power system that replaces a diesel-fuel operation that by late August will no longer run the lights, coolers and assorted other gadgets at Dangling Rope.

"We're investing $1.5 million in order to save $2.3 million," said Jeff Burks, director of the state's Office of Energy and Resource Planning.

It will take 20 years to achieve those results, but in the meantime proponents of the change say other benefits will become apparent. The distant roar of generators will be quelled for most of the day, though a propane-fueled backup power source will still run the noisemakers for up to eight hours a day during peak days of summer demand.

When the solar array is engaged, "You won't hear a sound except the wind," said Howard J. Rigtrup, deputy director of the state's Department of Natural Resources.

Some 557 tons of annual air pollution will be eliminated, said Burks. And the 36 barge trips a year required to provide 65,000 gallons of diesel fuel for the marina's generators will become a thing of the past.

"They've been talking about it for years and I'm kind of excited to get it going," said marina maintenance supervisor Ron Hockins, who said he was skeptical at first.

But Hockins said the solar array will require maybe a couple of hours of monthly maintenance, not very much in light of the fact that marina mechanics spend about that much time now every day working on the generators.

The solar assemblage, which faces south and sits on a naturally flat hillock out of view from the marina, is made up of 384 panels that will soak up solar energy on the 300-some sunny days that occur each year at Lake Powell. They are connected to a bank of batteries tied into an invertor that converts direct current to alternating current and will feed 250 kilowatts of electricity to the marina and its assorted outbuildings.

The system is the largest of its kind within the National Park Service, considered a pioneer in the field because many of its energy needs are in locations well beyond conventional power grids. Similar but much smaller setups are already in place at spots in Arches and Canyonlands national parks and at Natural Bridges National Monument north of Lake Powell and Glen Canyon National Recreation Area.

Several participants in the program shared the cost of the project, including Utah Power, ARAMARK, the Park Service, the U.S. Department of Energy, Sandia National Laboratory in Albuquerque, N.M., the Environ-men-tal Protection Agency and the state energy office.

Burks said the scale of the Dangling Rope project characterizes it as a model utility companies are likely to follow as they delve into Third World markets with communities well beyond the reach of hydroelectricity or coal-powered energy.

"This is the true prototype," he said.