The Solar Battery (Photovoltaics)

 

Bell Labs engineer testing solar battery in 1954
- from Bell Labs website

The original Bell Solar Battery (photovoltaic panel)
is used in an early test in 1955 in Americus, Ga.

This topic has always fascinated me since I was old enough to spell "solar battery" many decades ago, long before this country knew we were headed for trouble because of our dependence on foreign oil supplies. In fact, my dream since the mid 1970's has been to live in a solar powered home and drive an electric car recharged from solar panels by the time I retire. The USA will never prosper again until we totally free ourselves from  our dependency on oil from the terrorist countries in the Middle East.  Oil is literally a dinosaur technology and yet we continue to subsidize this archaic fuel supply when we should be funding research and production improvements in renewable energy source systems - especially solar!  Now for a little history of the solar battery and Bell Labs involvement about 50 years ago.

 

In the early 1950s R.S. Ohl discovered that sunlight striking a wafer of silicon would produce unexpectedly large numbers of free electrons. In 1954, G.L. Pearson, C.S. Fuller, and D.M. Chapin created an array of several strips of silicon (each about the size of a razor blade), placed them in sunlight, captured the free electrons and turned them into electrical current. This was the first solar battery. It could convert only six percent of the sunlight into useful energy. - Source: AT&T web page.

 

Fifty years ago, scientists at Bell Laboratories unveiled the first modern solar cell, using a silicon semiconductor to convert light into electricity. See magazine advertisement for this new Bell Labs technology. A similar advertisement can be viewed by clicking HERE.  Also, check out the May 3rd 1954 Time article and the July 4th1954 Time article.

 

Their demonstration inspired a 1954 New York Times article to predict that solar cells would eventually lead "to the realization of one of mankind's most cherished dreams -- the harnessing of the almost limitless energy of the sun.''

 

As early as 1962, when Bell solar cells powered Telstar, the world's first communications satellite, photovoltaic arrays have been recharging batteries and powering equipment in space. But the space market was small and never created enough demand for solar cells to drive down costs. That's why solar cells remained pricey, while computer chips, their cousins in the semiconductor world, became affordable so fast.

Over the last 20 years, improvements in manufacturing techniques gradually lowered the costs of solar cells. That has widened their use, which in turn has led to further expansions in the market and further economies of scale.

Meanwhile, for those sick of promises and wondering what solar cells have done for them lately, David Bishop, research vice president for Bell Labs, said one need look no further than the fiber-optic Internet.

Working in conjunction with another Bell invention, the laser, "The solar cell is the heart of all optical communication,'' he said.

Conceptually, it's simple. Electronic data from computers are routed to a laser, which converts the information to photons and pumps them through glass filaments. At the receiving end, a charge-coupled device -- an invention that operates on the same principle as the solar cell -- converts those photons back into electrons and electronic data.

So if the solar cell hasn't lived up to its energy-producing promise, it has played a vital role in creating the fiber-optic network "that can let any human being talk to any human being anywhere,'' Bishop said.
 

Bell Lab researchers Willard Boyle (left) and George Smith devised what would
become the charge-coupled device in a discussion of less than an hour in 1969.
Photo courtesy of Lucent Technologies Inc.

TIMELINE

• 1954: On April 25, Bell Labs unveils a solar battery that converts light into electricity.
   

• 1955: The first field trial of a rural telephone system making use of transistors and the Bell Solar Battery was held in Americus, Georgia. The Bell Solar Battery was installed on a part of this trial system in October, 1955, as an experimental substitute for ordinary batteries. Bell System engineers have ascertained from the Georgia tests that, from the standpoint of reliability and effective operation, the Bell Solar Battery mounted on a pole can be used to furnish electricity for rural telephone equipment. However, until raw material, technology and electrical storage become less expensive, it will be more economical to use conventional power sources for telephone systems.
   

• 1962: 3,600 solar batteries power the world's first communications satellite, Telstar.
   

• 1969: Bell scientists adapt solar principles to translate electronic data into light energy, leading to the charge-coupled device, or CCD, now used in digital cameras and the Internet.
   

• 1973: Arab oil embargo shocks the U.S. economy and awakens interest in solar energy.
   

• 1976: Solar power estimated to cost $55 per peak watt. Incoming President Jimmy Carter pushes short-lived subsidies to kick-start industry.
   

• 1984: Solar power estimated to cost $12.26 per peak watt.
   

• 1992: The United States leads the world in total power derived from solar cells, generating 43,500 kWp (kilowatts at peak), followed by Japan with 19,000 kWp and Germany with 5,619 kWp.
   

• 1997: Japan takes the lead with 91,300 kWp of installed solar power, passing the United States with 88,200 kWp and Germany with 41,890 kWp.
   

• 2001: Japan expands its lead with 636,842 kWp of installed solar power, while Germany's 260,600 kWp passes the United States' 167,800 kWp. Demand pushes solar power's estimated cost down to $3.50 per peak watt.

(Peak watt prices in 2001 dollars.)

Sources: Bell Laboratories, Energy Policy journal (1976 and 2001 solar power prices, in 2001 dollars), Worldwatch Institute (1984 solar power price, in 2001 dollars), International Energy Agency (total solar power by nation).