A brief history of Solar Energy

From the beginning, the sun has been personified and worshipped for the light and heat that it provides to the earth. Eventually, the worship of the sun was replaced with a more practical approach. Humans have never known a planet without a sun, when it is cold we all look for a sunny spot.

Where it all began

The first recorded use of utilizing the sun’s power was in the 7th century BC when magnifying glasses or crystals were used to light fires.century BC when magnifying glasses or crystals were used to light fires.

400 hundred years later in Egypt, mirrors were used to reflect the light from the sun to illuminate the entrances and corridors to their tombs. The sun dried mummies and houses were specifically built to trap the sun’s heat for lower daytime and higher evening temperatures. The design was simple, yet effective. Much can be learned from the ancients in harnessing passive energy in order for us to be more efficient.

The Romans and Greeks also used solar energy for domestic and ceremonial purposes. The sun’s energy was used to light torches for these various ceremonies. The Chinese also used mirrors and reflective objects to light fires for religious events; this was recorded in AD 20.

In 212 BC, Archimedes reportedly came to the aid of the Greek empire by destroying the Roman navy at Syracuse. They used highly polished shields to magnify and focus the sun’s rays on a specific point, many of the ships were set alight. This is still a hot topic among historians and scientists, but the Greek navy set fire to a wooden ship in 1973 using the methods Archimedes described in this ancient account.

The Romans also built bathhouses with the windows facing the sun. The so-called “sun rooms” got so popular in the Roman Empire, that a law mandated that every building should have access to the sun. This was recorded in the Justinian code in 600 AD.

Before Columbus reached the shores of North America, the Native American built their houses in much the same way as the Egyptians. They built their houses next to cliffs facing south. The houses trapped heat for the night and regulated heat during the warmer periods.

Meanwhile in the 19th century

The Swiss inventor Horace de Saussure made the first Solar Collector in 1767. The design constitutes an insulated rectangular box covered in glass with two smaller boxes inside. When left in the sun, the bottom small box reached temperatures well over a 100 degrees Celsius.

Sir John Herschel, the noted astronomer, made a hot box (similar to the one of de Saussure) while on an expedition in the 1830’s to the Cape of Good Hope in South Africa. It was a small mahogany container blackened on the inside and covered with glass, set into a wooden frame protected by another sheet of glass and by sand that was heaped up along its sides. The outcome of Herschel’s experiments with this hot box was not only scientifically interesting but also pleasing to the palate, as his notes indicate: as these temperatures [up to 240�f] far surpass that of boiling water, some amusing experiments were made by exposing eggs, meat, etc. [to the heat inside the box], all of which, after a moderate length of exposure, were found perfectly cooked. . [on] one occasion a very respectable stew of meat was prepared and eaten with no small relish by the entertained bystanders.”

Aubrey Eneas opened the first solar company in Boston, US, in 1900 and called it The Solar Motor Co. William J. Bailley invented a solar collector in 1908, which comprised of copper coils feeding an insulated box. This is very similar to the ones used today.

Although John Ericsson invented the parabolic trough in the mid-1870’s, the first quantifiable use was in 1912. Frank  Schuman built these troughs for a community in Meadi, Egypt. The power generated was used to power a steam generator, which gave power to a water pump, providing the communities in surrounding area with roughly 20 000  liters per minute. Following the success, Schuman planned to build 20 250 square miles of parabolic troughs, enough to provide 270 million horsepower. Unfortunately, World War 1 broke out and his dream was never realised.

Photovoltaic and the 21st century

The history of photovoltaic energy (aka. solar cells) started back in 1876. William Grylls Adams along with a student of his, Richard Day, discovered that when selenium was exposed to light, it produced electricity. An electricity expert, Werner von Siemens, stated that the discovery was “scientifically of the most far-reaching importance”. The selenium cells were not efficient, but it was proved that light, without heat or moving parts, could be converted into electricity.

A process used to make very pure crystalline silicon, known as the Czochralski meter, was developed in the early 1950’s. A small US satellite was powered by a cell producing less than one watt in 1958. In 1970, Elliot Burman developed solar cells that were significantly less costly, reducing the price from $100 to $20 per watt. Exxon spearheaded the research.

Then in 1973/4, the oil embargo allowed the solar industry to grow, In 1976, David Carlson and Christopher Wronski manufactured the first amorphous solar panel. Approximately 1.2 billion homes were using Solar Geysers by the 1990’s; it was becoming more and more popular. In 2005, Professor Vivian Alberts of South Africa invented thin film solar modules.

You can see solar cells almost everywhere. Solar powered aircraft that can fly higher than most aircraft, solar powered cars etc. Solar cells are quickly becoming a cost effective alternative that will allow for serious consideration as an alternative source of electricity.