A Brief History of Solar Power
The term "photovoltaic" comes from the Greek (phōs) meaning "light", and "voltaic", meaning electric, from the name of the Italian physicist Volta, after whom a unit of electro-motive force, the volt, is named. The photovoltaic effect is the production of electricity directly from the sun.
Today, solar power is used in two primary forms: thermal solar, where the heat of the sun is used to heat water or another working fluid which drives turbines or other machinery to create electricity; and photovoltaic, where electricity is produced directly from the sun with no moving parts.
The harnessing of solar energy is not new. In fact, sketchbooks belonging to Leonardo da Vinci show that he had been designing techniques to harness solar power during the fifteenth century. Development of modern solar energy dates back more than 100 years, to the middle of the industrial revolution. Several pioneering solar power plants were constructed to produce steam from the heat of the sun, which was used to drive the machinery of the time.
Solar cell technology dates to 1839 when 19 year old French physicist A.E. Becquerel observed that shining light on an electrode submerged in a conductive solution would create an electric current. In the 1880's, visible light converting photovoltaic cells made of selenium were built and had 1- 2% efficiency. In 1891 the first commercial solar water heater was patented by the father of American solar energy, Clarence Kemp. Einstein explained the photoelectric effect in 1905 for which he received the Nobel prize in Physics in 1921.
It was not until the 1950s that Gerald Pearson, Calvin Fuller, and Daryl Chaplin (of Bell Laboratories) discovered how well silicon worked as a semiconductor. Silicon is what solar cells and solar panels are generally made of today. By 1960 Hoffman Electronics increased commercial solar cell efficiencies to as much as 14% and today researchers have developed cells with more than 20% efficiencies. 20% efficient means that out of the total energy that hits the surface of a solar cell, about 20% is converted into usable electricity.
In 1958, a satellite called the US Vanguard I was launched, carrying a small solar array that powered its radios. Today, solar power continues to be the power of choice for satellites and space probes.
From the 1960's to the present oil prices play an important part of the economics of solar power and other alternative energy forms. In the 1960's cheap imported oil was the main energy competitor to solar power and restricted the overall solar technology market. During 1973 - 1974 the oil embargo allowed solar power to flourish. The US Department of Energy funded the Federal Photovoltaic Utilization Program that began installation and testing of over 3,000 PV systems.
An economic breakthrough occurred in the 1970's when Dr. Elliot Berman was able to design a less expensive solar cell bringing the price down from $100 per watt to $20 per watt. This huge cost savings opened up a large number of applications that were not considered before because of high costs.
The first solar power plant in the United States to provide electricity to a public utility was Arco Solar’s six-megawatt plant built in 1981 in the Mojave Desert. The facility powered around 2,400 homes and produced energy from 1982 to 1986.
The Gulf War of 1990 renewed interest in solar power as an alternative to oil and petroleum products. By the mid-1990's even though there were fewer tax credits and incentives for solar electric homes or heating systems, there were approximately 1.2 million solar heated buildings in the US.
In 2009, the US company First Solar reported that it broke the $1/watt cost barrier on photo voltaic manufacturing. Spain took over from Germany as the world’s largest photovoltaic market, and Portugal now has one of the largest solar arrays in the world.
Research in new material, cell designs and novel approaches to solar material and product development is still continuing. The price of photovoltaic power will be competitive with traditional sources of electricity within 10 years and we will soon be able to see the use of solar energy as a common scenario in everyday life. The future is bright for solar power!