SOLAR POWERS ITS WAY THROUGH HISTORY
Solar power has been around since the Seventh 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.Passive solar design - using architecture to get the most out of the sun’s capacity to heat and light up spaces indoors - was first used by the ancient Romans and Greeks.
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 concept of solar design was taken further by the Romans who promulated a law against obscuring a neighbour’s access to sunlight, and also using glass and mica to cover south-facing openings.
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 cultures used the natural storage of heat by rocks to good effect by building their homes into the sides of rocky cliffs.
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.Becquerel discovered that by exposing certain materials to light, it was possible to increase the electric current.
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.Both of these inventions failed to get off the ground because of the prohibitive cost of production.
Over time and all over the world, scientists were working out new ways of harnessing the sun’s energy.In 1876, William Grylls Adams discovered that by exposing selenium to light, it produced electricity without any need for moving parts or heat.
Although Albert Einstein is more widely known for his Theory of Relativity, it was his theories on the photoelectric effect that won him the 1921 Nobel Prize in Physics.
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.
Photovoltaic silicon solar cells were first used in a practical way in the late 1950s with the launch of the satellite, Vanguard 1, which had a solar powered radio.The first solar powered aircraft flew across the channel from France to England in 1981 under power from its sixteen thousand solar cells which gave off 3 000W of power.
The oil crisis of 1973 to 1974 accelerated solar power research as the Western economies realized the need to reduce their dependence on oil.When Dr Elliot Berman developed a solar cell that had more practical cost implications in the 1970s, it was the catalyst for the design of a much wider range of applications including lighthouses, off-shore oil rigs and remote homes.
Concern for the environment has galvanised research into finding viable alternatives to fossil fuels, such as wind power, geothermal and solar power.While the world has moved on significantly from the very early days of solar energy, the basic theory of solar power as a viable alternative to fossil fuels remains intact.
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