Affordable Solar Power for a Dollar a Watt

Affordable solar power took a step closer to reality in the late 1970s when the research arm of RCA made a breakthrough that brought the cost down to as little as a dollar a watt.

| March/April 1980

061 affordable solar power - Fotolia

Affordable solar power is almost in hand.


Despite what shortsighted critics say, solar power is the wave of the future . . . and—of course—it's been the basis of our energy supply all along, since most of our current power sources would not be available today if it weren't for of Sol. Unfortunately, the process of converting sunlight directly into electricity—which is the form of energy most useful to us—by means of solar cells has been prohibitively expensive . . . until now!

That's right . . . just recently, a genuine breakthrough in photovoltaic technology pioneered by a research arm of the Radio Corporation of America (RCA) has brought affordable solar power in reach. They've made it possible to reduce the cost of sun-produced electricity from an average of $10 a watt to $1.00 (or less) for that same watt . . . which, unbelievably enough, is even less expensive than some utility-supplied power!

Age-Old Technology

The truth is, photoelectricity has been around for some time. It was first recognized in 1839, and was eventually developed into a useful source of energy with the advent of wafer-type solar cells in the mid-1950's. In a nutshell, a conventional photovoltaic cell works like this: A semiconductor material (in this case, silicon, which is a component of sand and is thus plentiful) is first refined to a high degree of purity in an electric furnace. Next, this 99% pure material is "cleansed" even further through various chemical processes, and is then converted under intense heat from a granular form into a single-crystal state.

During the conversion process, the silicon is "doped" with either boron or phosphorus to form P (positive) or N (negative) ingots. The impregnated crystals are then sliced very thin and joined, P to N, using a doping agent and more heat. With that done, minute nickel or aluminum strips are attached . . . to conduct current and act as terminals. When sunlight penetrates the thin P-layer, a reaction takes place in the "barrier" between the P and N layers and electricity is produced.

Obviously, then, the cost of manufacturing a wafer-type solar cell can be quite high. Besides the expense of merely producing the necessary ultra pure silicon, the substance must be further processed by physically slicing the ingots . . . then each cell must be assembled, which also increases cost. So, not only are the necessary materials at a premium, but the manufacturing steps themselves run into big dollars.

The Secret's in the Sauce

How, then, has RCA broken through the price barrier? To put it simply, the firm has attacked the problem from a whole new direction. Conventional photoelectric cells are relatively effective in terms of light-to-power conversion, achieving an impressive 10% (or higher) efficiency in the field. However, to achieve such a high rate of efficiency, the cells must be manufactured from only the purest grade silicon . . . anything less simply wouldn't yield the magic number.

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