SOLAR POWERS ITS WAY THROUGH HISTORY
The earliest known uses of solar energy date from way back in the 7th Century BC.
The Ancient Egyptians used the sun’s heat to make bricks, which were formed by mixing mud and straw together and baking them in the sun. The ancient Greeks and Romans were the first to use what we now call passive solar design – architecture designed to optimally harness the sun’s rays for light and heat.
By building houses that faced south, they were able to get the most out of the winter sun.In doing so, they were able to reduce their dependence on firewood which wasn’t always plentiful, using renewable energy instead of fossil fuels.The Romans took solar design seriously, making it illegal to obscure a neighbour’s access to sunlight and using glass for windows.
Much less passive was the use of solar energy by the Ancient Greeks, who used bronze shields to direct the sun’s rays onto the wooden ships of the Roman army to set fire to them.Some early native cultures in America built their homes into cliffs to get the best use of the heat trapped in the rocky sides.
Much later on, in 1767, Swiss scientist Horace de Saussure was said to have built the world’s first solar collector or ‘hot ‘box’, but it was not until 1839 when French physicist, Edmond Becquerel discovered the photovoltaic effect that the platform for modern solar energy development was set.His major discovery was that exposure to light increased electric current in certain materials.
Mathematician Auguste Mouchout continued the French nation’s interest in solar power, and invented the first active solar motor and a solar powered steam engine.Both of these inventions failed to get off the ground because of the prohibitive cost of production.
Around the globe, scientists were experimenting with solar energy.In the lae 1870s, William Grylls Adams worked out that when light was shone on selenium, it shed electrons, thereby creating electricity.
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.It was the first time that something had been developed that could convert sufficient amounts of the sun’s energy to power ordinary electrical appliances.
The first practical application of photovoltaic silicon solar cells also came in the 1950s with the launch of the satellite, Vanguard 1.In 1981, an aircraft powered by 16 000 solar cells giving off 3 000 watts of power flew from France to England.
The oil crisis of 1973 to 1974 accelerated solar power research as the Western economies realized the need to reduce their dependence on oil.A large number of new applications was made possible after Dr Elliot Berman designed a less expensive solar cell in the 1970s.
Concern for the environment has galvanised research into finding viable alternatives to fossil fuels, such as wind power, geothermal and solar power.And whilst technologies today are a far cry from baked mud and straw bricks, the basic idea of using solar energy as a viable source of renewable energy remains.