Solar Power from the Very Beginning
Now in the 21st century we think we are at the cutting edge of technology when we put solar panels on the roof and use them to generate electricity or heat our water. Solar energy has really taken off in the last decade, but has a history going back many centuries.
Many of man’s first scientific discoveries were made in the Ancient worlds of Greece and the Roman Empire, but even before this time, man was well aware of the power of the sun and how it moves around the sky. The summer and winter solstices were very important celebration times, and as far back as 400BC the Ancient Greeks were designing their homes to be south facing to make the most of the warmth of the sunshine during the cooler winter months. Even before this time, our ancestors had learned that concentrating the rays of the sun through a mirror or other shiny object could start a fire or burn things. Greeks and Romans used this principle to use the sun to light ceremonial torches.
There was not much progress on the solar front for the next 1500 or so years, although man was still constructing buildings with large windows to capture light and retain heat through the colder nights. The next main leap forward came in 1767 when a Swiss scientist called Horace de Saussure came up with the idea of using several layers of glass to make a small greenhouse which would use the power of the sun to cook items placed inside. The theory was sound, but de Saussure struggled to make a practical, working model which demonstrated his ideas. Experiments continued through the 18th and 19th centuries, and several scientists managed to make working hot boxes which raised the temperature inside to more than 100C, and managed to boil eggs and cook other items inside.
Conversion to Electricity
The development of modern solar power as we know it started in the 1870s, when a pair of scientists realised that when the sun’s rays hit a thin layer of selenium, electricity was produced. In 1891, an American inventor, Clarence Kemp, invented the first machine which used the selenium cells to heat water, although this was not a huge commercial success. By 1908, many eminent scientists including Albert Einstein were working on practical applications of solar power, and the first solar collector design of coils of metal in a box was patented. Although the design has been refined many times since, this is the first real modern solar cell.
In the late 1950s the Americans were starting to send satellites up into orbit, and investigations began into ways of powering the voyage. Many different American laboratories began work on making lightweight, reliable and durable solar cells which could be effectively attached to rockets and satellites. As research progressed, the cells became more reliable and smaller. By the 1960s, Japan was beginning to look into more domestic uses for solar power, and in 1963 put the first solar panels on a lighthouse.
1970s and 1980s
Solar power was not big news through the 1970s, but research continued into making cells which were ever more efficient and cost effective. In 1981 the first solar powered plane crossed the English Channel, and in 1982 a solar powered car crossed Australia. As the 1980s progressed, everyone became more interested in environmental issues, and interest in solar began to rise again, with research mainly concentrated in Australia and the USA.
Here in the UK, in 1992 we only had 172 gigawatts worth of solar cells installed. By the end of 2012, this had increased to over 1.3 million gigawatts, with the greatest increase in solar panels since 2010. This is largely as a consequence of government incentives which helped lower the cost of installing solar panels in the first place, and also gave a rebate on any electricity produced. We are also as a nation becoming far more inclined to adopt renewable energy sources, and with the government committed to increasing the amount of electricity generated in this way, the number of solar cells on UK houses is set to rise even higher in the future.