Solar collectors on 10 roofs here are harbingers of a project that the Tennessee Valley Authority calls a crucial test of solar energy's future.

"The whole country will be watching Memphis because this is where the solar effort will pivot to success or fall apart," said S. David Freeman, TVA chariman.

A lot of people also will be watching TVA. The Memphis solar project is one of the first efforts by the utility to rebuild its "grassroots democracy" image which has been tarnished by decades of highlandedness that led President Carter to describe TVA as "just another power company.

One of the Carter and Freeman goals is to return TVA to its pioneering energy role - this time financing and promoting solar energy.

The 10 collectors already installed here are planning to become "The Memphis 1,000" in the largest utility-assisted solar project ever attempted in the United States.

TVA thinks its program eliminates the two biggest obstacles to solar acceptance - high initial cost and the lack of quality control in a young industry.

The $2,000 cost of installing solar hot water systems in existing houses will be loaned to its customers by TVA at 3.37 percent interest over 20 years. The customer will pay a constant $13 on his monthly utility bill to cover the loan and all maintenance.

"In the first month, it's already a break-even proposition," said Travis Price, TVA architect and solar program coordinator.

The major lure to customers, however, is that as electric rates go up, their hot water bill doesn't. TVA rates have double in the last five years and the utility experts an average future annual increase of at least 8 percent.

"One thing people here know as sure as they know that Jesus is coming back is that their electric bill is going up," a Tennessean remarked.

The people of Memphis are apparently eager to enroll their houses in the Memphis thousand. TVA opened its solar office here this month and has over 750 applicants although it has done no advertising.

On each successful applicant's house (about 9 percent are found too shaded or otherwise unsuitable for solar) the collector is placed on the roof and hooked up to two large hot water tanks. One tank is solar, the other is a storage tank with an electric booster system for cloudy days.

Price says the solar heat will take care of 70 percent of a family's hot water needs. The average family uses 20 gallons of hot water per person per day. A family that wants to make the effort to avoid using the booster as much as possible can get close to 100 percent of its hot water from the solar system, Price said.

Calvin Green, a data systems specialist at Memphis International airport, had one of the first 10 systems installed June 26. His total electric bill for hot water in July and August registered on a separate meter was $2.85, Green said. He stopped keeping track after that, and now he is interested in heating his house with solar power.

Price wants to move from hot water to space heating and space cooling, too. TVA is designing a million-square-foot solar building for its power division officers in Chattanooga which Price hopes will be a model for large solar buildings of the future.

TVA is also looking into designs for outfitting existing house with solar heat and for new, solar houses.

But in the short term TVA's solar chips are riding on the Memphis 1,000.

"This is the beach landing," Price said. Although the project offers customers an inexpensive way to go solar, it contains no subsidy from TVA. In fact, TVA stands to save, too.

Each solar water heater saves TVA one kilowatt of generating capacity and it costs about $700 per kilowatt to build power plants, according to Price and colleague Doug Brownlow. By advancing the money for 100,000 solar water heaters at $2,000 each, TVA would be making a $200 million 20 year investment which would be repaid, and by avoiding the need for as many new power plants (whose cost is borne by all ratepayers) it saves all customers money.

The solar water heaters are designed to shave TVA's peaks - the times when most electricity is needed and it becomes most costly to produce.

Each solar unit's electric booster has a timer that prevents it from turning on during the winter peak of 6 a.m. to 9 p.m. and summer peak of 10 a.m. to 8 p.m.

TVA has other new angles in the solar program. Equipment is being handled for TVA by South Memphis Development Corp., a two-year-old group seeking to aid economic devtlopment of the decayed downtown areas where, executive director Marba Holeyfield said, unemployment among black youths is 50 percent.

Crews to install the solar systems will be trained at the solar project offices the development corporation shares with TVA and the local utility, Memphis Light, Gas and Water.

TVA ustd to inspire loyalty not only for its low rates (they are still among the nation's lowest) but for its support of small cooperatives, of unions and of farmers. Today despite "People in Partnership" motto, it is no longer so popular in the 80,000 square miles that everyone calls "the valley."

It became the largest purchaser of strip-mined coal and one of the nation's leading polluters by burning high-sulphur coal. TVA acquired an anti-union reputation among some by buying non-union coal and antagonized others by becoming the country's most aggressive promoter of nuclear power.