A community built with the sun in mind

A lot of people are ''looking'' at solar energy these days - attracted by the prospect of collecting state and federal energy tax credits and cutting down on ever-rising utility bills.

But many have found that solar equipment installed at home doesn't always perform up to expectations and that, even with tax credits, it can take a long time to pay for itself.

New home buyers may face better opportunities for savings - plus some perhaps surprising additional benefits - by purchasing houses built with solar energy use in mind.

Builders are increasingly turning to the solar option in California, at least partially because of an aggressive campaign on behalf of solar energy by the administration of Gov. Edmund G. Brown Jr.

One well-established residential construction firm that has recently made a major commitment to solar housing is the Southhampton Company. Its 2,300-acre planned community covers half the area of this old city 34 miles northeast of San Francisco. The community, called Southhampton after the bay its residents can see from atop the area's rolling hills, now contains 2,400 of its projected 5,000 housing units - apartments, town houses, and single-family homes.

At least 195 of the houses are to be solar-heated - the largest such development in the state, according to several sources.

Victor Freeman, vice-president and marketing director of Southhampton, says 42 of the solar homes have been sold to date, and 25 more are under construction.

Mr. Freeman says that when his firm decided to build solar-heated houses, it set guidelines requiring several designs that included a reliable solar system making maximum use of both active and passive heating. It also wanted a minimum of 50 percent heating by solar in order to qualify for tax credits and promotional opportunities through the Pacific Gas & Electric Company (PG&E). And all this at affordable prices.

An architectural team headed by George Wolfson of Menlo Park, Calif., was handed the assignment and told to take all the time it needed. Mr. Wolfson says the solar business ''was like a nightmare,'' with many people trying to market different types of equipment of unproved reliability. He and his associates sought the help of an engineer experienced in the solar field, Richard Bourne of Davis, Calif.

The architects set out to design solar homes without some of the ''more exotic passive features that might meet buyer resistance,'' says Wolfson. At the same time, they wanted to achieve 25-to-30 percent heating through passive solar means ''when conditions were right.''

Mr. Bourne designed a system which Wolfson says is ''quite simple compared with most, with the emphasis on reliability.'' Components were thoroughly tested over the two-year design period. The major objective, aside from meeting the 50 -percent solar heat goal, was to make the system ''trouble free.''

This is what Southhampton has come up with: Six house plans of very compact design that belie their relatively small size (square footage ranging from 1,079 for the smallest two-bedroom model to 1,618 for the largest three-bedroom). Prices ranging from $107,000 to $132,000 - moderate in the San Francisco area for quality housing within reasonable commuting distance of the city.

The developers have a tie-in with First Nationwide Savings (formerly Citizen Savings of California) which letss them provide mortgage interest rates not exceeding 14 percent. A second advantage is derived from the solar equipment in the houses, which is valued at $10,000; this makes the buyer eligible for $4,000 in tax credits.

Each house has a roof with a 30-degree pitch with southern orientation for maximum solar-collection advantage. The solar panel blends unobtrusively into the line of the shake roof.

Landscaping includes deciduous trees on the south side to provide shade in summer but let through sunlight in winter, and evergreens on the north exposure for protection.

Outside walls are six inches thick with R-19 insulation; the ceiling has R-30 insulation. Windows are dual-paned -- something that will be required by law in all new California housing starting next June. The foundation is an insulated concrete slab. (Slab foundations are common in California houses built in the last two decades.)

When conditions are right, says Wolfson, the desired 25 to 30 percent passive solar heating is attainable.

Here is how the active solar system works: When sufficient sunshine is present, water is automatically pumped to the rooftop panels and circulated back to a heavily insulated, 350-gallon storage tank (well-concealed but easily accessible from within the house) until the water temperature reaches 160 degrees F. This provides for forced-air space heating as well as hot water. When sunlight is insufficient to sustain solar heating, the system automatically switches to natural gas heating.

One feature the designers make a special point of is that no water is left in the roof panels when the outside temperature gets to the freezing point and the solar system is not working. This avoids a problem that has caused grief to some solar units - water freezing in the panels.

Under the ''Suntherm'' designation PG&E grants to new housing units that qualify, the utility provides technical and promotional assistance. It also monitors the solar systems, although it has not yet begun to monitor the Southhampton units.

Judith Judson, who moved into one of the two-bedroom houses last Oct. 1, has been doing her own monitoring. She says she is very pleased. It costs her much less for gas to heat her new home than it cost in the smaller town house she previously occupied.

She says the solar system has been operating at least 85 percent of the time, despite an unusual number of rainy days in this area since she moved in. Residents can check the operation of their solar units easily by looking at an electronic readout panel located beside the water storage tank.