The US Department of Energy's much-publicized photovoltaic (PV) goal was to develop sun-produced electricity to the point where its cost would be in the region of 50 cents a peak kilowatt by 1986. That goal has since been amended to 70 cents a peak kilowatt, a still-optimistic assessment.
The flood of press releases making this announcement and similar optimistic reports from private industry, however, have tended to set back public acceptance of residential PV systems.
''Why put it in now, when it will be cheaper down the road,'' most people reason.
PV modules, in fact, have slightly increased in price during the past two years - and there is no guarantee that the department's goal will be achieved so soon. In addition, the trend in industry, with the backing of the present Reagan administration, is the development of large low-cost PV systems for the utility companies rather than smaller systems for the individual.
And yet, as those individuals already using domestic PV systems point out, photovoltaic systems can make it possible for every home and building to be its own power station. If a tree falls across conventional power lines in a storm, it plunges a whole area into darkness.
The PV-powered home, immune to this type of disruption, is generally safe from similar, storm-related damage, too, as the panels are open to the sun and generally clear of overhanging tree limbs.
The current PV cost is a little under $10 a peak kilowatt, down dramatically from $1,000 just 15 years ago. This makes PV competitive with home diesel generation right now and also for remote homes where running the power line could cost $5,000 or more.
On average, a single panel of PV cells will produce 11 amperes of electricity (2 amperes an hour) given 5 1/2 hours of sunshine. That's enough to run two 15 -ampere lights for three hours, plus a cassette/AM-FM/stereo for two hours and a black-and-white television set (12 volts) for an hour.
As a matter of fact, there would then be enough power left over for six minutes of intermittent use by a kitchen blender.
Steven Strong, whose Solar Design Associates of Lincoln, Mass., recently broke ground for the country's first full-size stand-alone PV home, says photovoltaics will spread around the country in the coming decade by what he sees as the ''trickle-down, trickle-up'' pattern of demand.
Trickle-down influence will come from those affluent homeowners who want to be the first to use innovative products and install large PV systems. Trickle-up pressure will come from the growing number of people who have settled far from conventional power lines and find it economical to turn to PV panels for basic lighting and other needs.
The two market segments will grow steadily closer, according to Strong, creating a demand that will be large enough to justify full-scale PV production with the attendant economies of scale.
About 10 percent of the energy consumed in the United States by the ultimate user is electricity. Yet it takes fully 30 percent of all energy used in the US to produce that 10 percent, because of inefficiencies in production and transmission. PV transmission loss from the roof into the house is nonexistent by comparison. In any event, the original energy is free.
Meanwhile, as Joel Davidson, who powers his own remote Arkansas home with a 6 -panel system, sees it: (for those who use electricity conservatively,) ''the good news on photovoltaics is not 1986 or anytime this decade. It is now.''
''Solar Electricity. Making the Sun Work for You'' ($12.95) is an excellent backgrounder, written in nontechnical language for the layman interested in photovoltaics. It is available from Monegon Ltd., 4 Professional Drive, Gaithersburg, Md. 20760.