SOLAR POWERS ITS WAY THROUGH HISTORY
The earliest known uses of solar energy date from way back in the 7th Century BC.
In ancient Egypt, heat from the sun was used to bake a mixture of straw and mud into bricks which were used for construction.Ancient Greeks and Romans recognised the benefits of what we now call passive solar design – using architecture to maximise the sun’s capacity to heat and light indoor spaces.
In order to get the maximum benefit from the winter sun, they made sure their buildings were orientated towards the sun.At the same time, they were able to cut down on firewood which was scarce, displaying a very early switch from fossil fuels to renewable energy. The Romans advanced the concept of solar design by using glass for windows, and even promulgated a law which made it illegal to obscure a neighbour’s access to sunlight.
Energy from the sun was also used by the Ancient Greeks who used bronze shields to focus the sun’s rays onto the wooden ships of the Roman army, setting them on fire. Some native American cultures built their homes against the sides of rocky cliffs to benefit from the natural storage of heat harnessed during the day.
Later on in 1767, a Swiss scientist called Horace de Saussure was believed to have constructed the first solar collector, but the real momentum for solar energy development came in 1839 when French scientist, Edmond Bequerel discovered the photovoltaic effect. He discovered that electric current in certain materials could be increased when exposed to light.
French scientists continued to experiment with solar power, with a notable achievement by Auguste Mouchout in developing the first active solar motor as well as a solar-powered steam engine.The high cost of production prevented both inventions from succeeding.
Around the globe, scientists were experimenting with solar energy.In 1876, William Grylls Adams discovered that by exposing selenium to light, it produced electricity without any need for moving parts or heat.
In 1921, Albert Einstein who is better known for his Theory of Relativity, was awarded the Nobel Prize in Physics for his theories on the photoelectric effect.
In the 1950s, Bell Laboratories (now known as AT & T Laboratories) developed the first silicon solar cell which could generate a measurable electric current.This was the first time that a cell had been developed that could convert the sun’s energy to power everyday appliances.
The launch of the satellite, Vanguard 1 in the fifties marked the first practical application of photovoltaic solar cells. In 1981, the first solar powered aircraft flew from France to England powered by 16 000 solar cells giving off 3 000 watts of power.
The Arab Oil Embargo in 1973/4 forced western economies to rethink solar energy research as a means of reducing their dependence on oil.In the 1970s, Dr Elliot Berman designed a less expensive solar cell, which enabled a large number of new uses to be considered, such as railroads, navigation warning lights and homes in remote areas.
Environmental concerns have also escalated the search for renewable energy resources such as solar power, wind power and geothermal power.And whilst solar technology today is powering far more than a hand-held radio, the basic idea of solar power has remained the same since ancient times – it is a viable renewable energy source.
