His office is small - 120 square feet - and is in a structure separate from his company's other offices. One PV panel on the roof powers an evaporative cooler; a second panel powers all the office equipment, including ceiling and desk lights; a computer with two disk drives, a printer and a monitor; a color television, an electric typewriter and assorted 12 volt direct current and 120-volt alternating current devices. All the equipment draws its power from batteries charged by the PV panels, directly or through an inverter. 

Davidson has been a photovoltaic consultant for years, here and in the Midwest, and now is an executive of the William Lamb Co., North Hollywood. He estimated the cost of “PV-ing” his office at about $6,000 but added that he already had some of the equipment. He said an economical user could equip a personal office with more modern equipment - including devices to make the panels “track” the sun and thereby increase efficiency - for about $10,000. 

This would be feasible in a secluded area where a power line had to be run in, he said, because a power line would cost about $10,000 a quarter-mile. Also, he added, such office equipment would be eligible for both solar and investment tax credits and depreciation. 

In recent years, the mystique of solar energy has become much less mystic. If you lay a rock in the sun, it gets hot; if you put a pan of water in the sun, you get hot water - that's about all there is to it, even though the applications can get very complicated and sophisticated. 

With one exception. It's hard not to get a feeling of having seen magic performed when a beam of light falls on what looks like noting but a slick of black, shiny rock…and a lamp lights or a motor starts running. You're observing the photovoltaic process, in which a beam of light (solar or just from an electric bulb) falling on a specially made silicon crystal causes a flow of electricity from that crystal. 

Photovoltaic cells are pretty expensive but not so expensive as they were at first, when they were developed for use in the early spacecraft. There is at least this one office operating today and houses have been built that are completely independent of the local electric utility.