MODERN LESSONS FROM ANCIENT TIMES
Solar power has been around since the Seventh Century BC.
In ancient Egypt, bricks for construction were made from shaping a mixture of mud and straw into blocks and baking it in the sun.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 took solar design a step further by covering south-facing building openings with glass or mica to prevent the heat of the winter sun from escaping, and even made a law against obscuring a neighbour’s access to sunlight.
Solar energy was also used as a weapon of war as early as 200 BC with the ancient Greeks using bronze shields to direct the sun’s rays onto the Roman’s wooden ships, setting fire to them. 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.
The world’s first solar collector is said to have been built in 1767 by the Swiss Horace de Saussure, but it was only in 1839 when Frenchman Edmond Becquerel first showed photovoltaic activity that the foundation for modern solar power research 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 inventions failed due to high production costs.
Scientists all over the world were experimenting with solar energy. In 1876, William Grylls Adams discovered that selenium produced electricity when exposed to light, without the need for heat or moving parts.
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 cell capable of converting enough of the sun’s energy into power to run everyday electrical appliances.
The launch of the satellite, Vanguard 1 in the fifties marked the first practical application of photovoltaic solar cells.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 Arab Oil Embargo in 1973/4 forced western economies to rethink solar energy research as a means of reducing 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 been a major driver of research into renewable energy sources, including solar power, geothermal and wind 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.