In a world where we are using non-renewable resources much faster than the Earth can regenerate them, we need to come up with efficient and cheap alternatives. A huge step forward in the development of renewable technology is the solar panel; converting sunlight into electricity.
Many people think of solar panel technology as a modern concept. Yet scientists have been harnessing the power of solar cells for almost 200 years.
The First Steps
The first major movement in solar panel technology occurred in 1839, when Alexandre Becquerel discovered the photovoltaic effect. This occurs when material generates electrical current due to exposure to sunlight.
However, it was not until 1888 that Aleksandr Stoletov built the first solar cell. The renowned Russian physicist’s discovery derived from his experiments with the photoelectric effect, which was only discovered by Heinrich Hertz the year before. This discovery involved the emission of electrons when sunlight is absorbed.
Despite these early finds, solar panel technology didn’t become widely-known until 1905, when Albert Einstein published a paper stating his theory that light is made of tiny particles.
Building on the work of Einstein, Stoletov et al, Bell Laboratories produced a more effective solar cell in 1954. However, the cell was inefficient and cost US $250 to produce just 1 watt of electricity.
Bearing in mind that a coal plant could generate the same amount of power for just two or three dollars, it would be some time until solar panels would become popular. Yet, despite the fact that solar panels proved too expensive for everyday use, they proved very useful to the space program. In fact, when NASA launched the Vanguard 1 satellite in 1958, they used solar cells as its main power source.
In 1959, Hoffman Electronics developed a solar cell with a 10% efficiency rating. This was put into use in 1967 on the Soyuz 1 marked the first time solar energy was used to power a manned spacecraft.
For years, solar cells were used almost only for space flight. In 1973, NASA fitted solar cells on the Skylab space station which gave it enough power to orbit the Earth until 1979.
Throughout the 1970s, solar panels would continue to become more efficient. This was true to such an extent that President Jimmy Carter had them fitted at the White House in 1977; Carter even offered incentives to those who used solar power. Developments over the previous 20 years brought the cost per watt of solar energy down to $20 by 1983.
In 1991, President H.W. Bush opened the National Renewable Energy Laboratory to continue work with solar energy. By 1999, photovoltaic production had hit 1000 megawatts (MW) in the US alone.
The technology available to harness the power of solar energy continues to improve; it is only a matter of time until it becomes the major source of power for homes across the globe.