PHOTOVOLTAICS TODAY

Image Gallery

Article Tools

Image Gallery

Print

E-mail

Comments

RSS

Solar cell technology is in a state of transition, and now may be the time to get involved.

PHOTOS COURTESY OF ARCO SOLAR

When THE MOTHER EARTH NEWS got its start some 15 years ago, photovoltaics (the direct production of electricity from sunlight) was little more than an expensive spaceage curiosity used on earth-orbiting satellites. Over the years, though, we've seen solar cells migrate down to terra firma. . . and MOTHER has done her best to keep you up-to-date on the transformation of photovoltaics into a consumer technology. Today it's time to review recent progress in the field and let you know what's currently available.

WEATHERING THE STORM

Since 1980, we've seen many alternative energy sources fall by the wayside (at least temporarily) as oil prices have eased. A gallon of gasoline that cost 50¢ 12 years ago, be fore the OPEC oil embargo—you remember, don't you?—goes for just slightly more than twice that price today. And if you take inflation into account, gas prices haven't increased at all over that period! This unexpected stability in fossil fuel costs has wreaked havoc with the development of many renewable technologies, but photovoltaics has not only survived—it has, by comparison, actually flourished! Sales (on a per-watt basis) have increased by more than 550% since 1980, though much of the 1983-84 increase was from Japanese production of modules for consumer electronics.

Photovoltaics, probably more than any other renewable technology, lends itself to gradual expansion. The modular design of photovoltaic systems-you can start with one panel and add more later—allows us, the consumers, to get involved for a reasonable amount of money and expand our systems as finances are available. By the same token, expandability has saved PV companies from an all-ornothing sales syndrome. Residential panel producers haven't made a lot of money lately, but a surprising number have managed to stay in business. The flexibility these innovators have demonstrated has gradually reduced the cost of panels, and it has virtually guaranteed solar electricity a place in our energy future.

HOME-SCALE PV MATURES

The typical photovoltaic array has changed significantly in the last five years. Not only are different cells being used in many cases, but the systems themselves have become much more sophisticated. Five years ago, lowvoltage arrangements were all the rage—and for good reason. Panels were so expensive back then that most people couldn't afford many, so the voltage was inherently limited. The industry grew up on the concept of 12-volt modularity, so 12-volt systems were what you found.

But PV practitioners soon found that low-voltage systems suffered from high internal power losses that degraded overall performance. Conventional household wiring designed for high-voltage, alternating-current (AC) electricity wasn't stout enough to handle the high currents imposed by low-voltage, direct-current (DC) electricity—remember, power is the product of voltage and current—and the results of trying to adapt 12-volt power to a normal home were often disappointing ... especially for inexperienced owner-installers.

RSS | Comments | E-mail | Print