Dennis Kobza will be one of the first California homeowners to watch his electric meter spin backward - legally. Mr. Kobza, a Palo Alto architect, has just finished building his ''dream house,'' a $425,000 rambling ranch-style estate not unlike many others here, but with one exception: Mr. Kobza will power his five-bedroom, 4,356-square-foot home almost entirely with the sun's energy.
Ninety photovoltaic panels mounted on the roof at a 45-degree angle are expected to produce 90 to 110 percent of electric needs, depending on weather conditions.
''We are 100 percent electrical,'' says Mr. Kobza, who will live in the house with his wife, Doris, and their two children.
The system was produced by a subsidiary of the Atlantic Richfield Company and is expected to generate 3,185 watts an hour during peak sunlight hours. As a result, Mr. Kobza eliminated all gas appliances.
For a combination of aesthetic and practical purposes, the photovoltaic panels were installed on the westerly side of the roof and can't be seen by neighbors from the street. The system converts sunlight directly into electricity.
''My clients were always asking me about photovoltaic panels,'' the architect says, ''so I thought, why shouldn't I, of all people, do what I can?''
He acknowledges that the cost of the photovoltaic panels is expensive - about
''They cost $800 a few years ago, now they're $400, and soon they'll be $200, as more are manufactured,'' he says.
Kobza estimates that the total cost of his equipment will be about $65,000, including a $7,000 computer-controlled ''inverter.'' This feeds electricity into the home and shifts surplus electric power to the city utility when the amount produced exceeds the household's immediate needs.
During the average of 10 hours of sunlight when the family is away from home, the Kobza rooftop system will generate a total of 32 kw of power, much of it going into the local power network. Then, with the family back in the house, it will begin taking energy out of the system.
The Minnesota-born Kobza says that with the energy saving - plus state and federal energy-conservation, investment, and depreciation tax credits - his equipment will be fully paid for in five years.
Kobza has operated his own architecture firm since 1962, designing residences , offices, and commercial buildings.
While most utilities, even those in the Sunbelt, view solar electricity generation as still too costly and somewhat inefficient on a large scale, Kobza seems to be showing that it can be feasible on a small scale.
Rick McClure, Palo Alto's solar program coordinator, says: ''Photovoltaic systems have been used successfully in remote areas where electricity isn't readily available. But to my knowledge, Kobza is the first person to build that kind of system in the middle of a residential area served by a utility.''
To that, he adds: ''I can hardly wait to have the meter smoking in reverse.''