PHOTOVOLTAICS; A Maine island plugs into the sun

The dinner conversation covers a wide range of topics, yet we keep returning to one main subject: energy and the goal of energy independence for the homeowner.

Sandra Dickson recalls watching a debate the previous year on Maine's public TV channel. The subject: nuclear power. Solar energy, particularly the meaningful generation of electricity by the sun (photovoltaics), was 30 to 40 years away, according to a participating professor.

Ms. Dickson disagrees vehemently. The very television set which brought the debate ''loud and clear into my living room'' was powered solely by the sun. Indeed, the background music we listen to during dinner comes from a sun-powered stereo set and, apart from two candles on the table, the lighting in the room is the direct result of translating sunlight on the roof of her home into electricity.

The source of power for the electric pump that brings water into her island home all winter long is also the sun.

In Ms. Dickson's experience, then, electricity from the sun is already ''decidedly meaningful in my life.'' It has not proved so very expensive, either. She talks of a little in excess of $1,000, after tax credits, for the two-panel system that she originally installed (since upgraded to four panels).

Monhegan is a tiny island some 12 miles out into the Atlantic Ocean, and its 700 summer residents are reduced to 85 when winter sets in. It is so remote it doesn't even have a telephone link with the mainland, let alone public-utility power cables. In the past electricity had to come from a diesel generator throbbing noisily in the shed or else it didn't come at all.

Now another option, thoroughly competitive with diesel, is coming slowly but surely to the island.

Dr. Alta Ashley had a six-panel system installed for just under $6,000 (before tax credits) right after the Dickson system became operational. In the two years since then a dozen homes have turned to quiet, pollution-free photovoltaic electricity. Two effective examples soon got others interested.

''In a few more years we may have a much more peaceful island,'' says Ms. Dickson hopefully. That would be welcome, because the throb of diesel generators is an almost constant background noise on this otherwise peaceful New England island.

Like Ms. Dickson, Joel Davidson is remote from the power companies. His Pettigrew, Ark., home sits, island-like, in a sea of tree-covered hills, two miles from the nearest utility pole.

Sure they'd be happy to string a cable for the Davidson family, the power company said, if Mr. Davidson would get the land cleared and send the utility a check for $1,500. In addition, he would be required to pay a minimum electric bill of $45 a month for the next five years. As he reasoned, even if he could handle the hassle and cost of the initial installation, his family wouldn't use that much electricity in a month without trying really hard.

The only alternative, he believed at the time, was to do without.

It was particularly tough trying to start the car on Monday mornings after running the reading lamp on power from the automobile battery all weekend. Then Davidson discovered something nice about photovoltaic electricity--that it wasn't too expensive to install if you plan to limit its use to those operations where alternative-power options are not particularly effective.

Joel Davidson now has six photovoltaic panels on the roof of his house which power the lights, TV set, radio, a fan for summer cooling, and some power tools. Because he did the installation himself, the cost, including secondhand storage batteries, totals in the region of $2,000. Deduct the tax credits and he has a system that cost him less than a power-line installation--and the electricity is free.

''My house is my own private power station,'' Davidson says with a smile.The point that both Sandra Dickson and Joel Davidson emphasize is that photovoltaic electricity is practical right now, depending on the circumstances and the expectations from electricity.

David Sleeper, president of Brook Farm Inc., an alternative energy consulting firm in Falmouth, Maine, and one of the very few contractors now installing small domestic photovoltaic systems in the New England area, contends that photovoltaics is considered prohibitively costly only because industry assumes that the heavy use of electricity in homes--electric stoves, washing machines, dryers, frost-free refrigerators and freezers, blenders, air conditioning, electric can openers, etc.--will remain the norm for all time.

It doesn't have to be that way, Mr. Sleeper says.

''Limit the use of electricity to lighting, radio-TV, and other low-energy appliances, and photovoltaics becomes affordable,'' he insists.

Sandra Dickson and Davidson are examples, as he sees it, of ''using electricity the way we used to back in the '30s.'' Mr. Sleeper notes that on Monhegan, where residents have to generate their own electricity one way or another, individual homes consume 60 percent less electricity than on the mainland.

Ms. Dickson cooks and heats water with bottled gas and heats the home with wood. The refrigerator also runs on gas.

Gas is ''just as convenient and better to cook with than electricity,'' she contends, ''and wood heat is the most comfortable you can get.'' But there are no alternative-energy sources for radio and TV; and while you can get by on oil lamps, she says, ''there's nothing more pleasant (after you have done without for several years) than to come home at night and--click!--instant light.''

Photovoltaic cells convert sunlight into direct-current (DC) electricity, whereas conventional household appliances use AC (alternating current). One answer is to buy an inverter to convert DC into AC. But inverters can be expensive, and there is a 20 percent loss of power during the conversion. So, both Ms. Dickson and the Davidsons turned to the recreational-vehicle industry for appliances that run on DC current (auto batteries supply DC power).

Apparently, there is virtually no appliance that the industry does not turn out for those campers who demand all the comforts of home while they are on the road.

Power tools, however, are an exception. So Davidson has a small inverter which he uses just in his workshop. Since he uses power tools infrequently, he can readily live with the 20 percent loss of current in the conversion.

Neighbors of Ms. Dickson's, Dot and Alfred Stanley, already had a diesel generator when they installed six photovoltaic panels (the generator now provides backup power). So they went the full inverter route, converting all DC power, when it is drawn from the storage batteries, to AC.

According to Mr. Sleeper, fully installed systems (photovoltaic panels, deep-storage batteries, voltage regulator so the batteries won't overcharge, and inverter) can cost from $3,000 to $8,000 before tax credits.

Davidson got his system so inexpensively because he did the installation himself. He also bought his panels wholesale by getting others to join with him and place a bulk order.

He has since established a photovoltaic co-op which anyone can join by sending $2 and a self-addressed, legal-size envelope (with two 20-cent stamps) to Joel Davidson, General Delivery, Pettigrew, Ark. 72752). He collects orders and money and sends them on to a California manufacturer which then ships direct to each buyer. The cost comes in at 15 percent under retail.

Sandra Dickson is likewise committed to spreading the word on affordable photovoltaics. Send a stamped, self-addressed envelope to her at Solar Works, Monhegan Island, Maine 04852, and she will tell you ''how to get an affordable, small-scale photovoltaics system installed in your home.''