Category: Solar Energy

Solar Cell History | Timeline Of Solar Cells

Mankind has been harnessing the energy of the sun since the seventh century B.C. The sun’s rays shower the earth’s surface and humans have been using them to satisfy their energy needs. Each hour of sunshine theoretically will contribute to satisfy the globe’s energy demand per annum. The ancient civilizations particularly, Rome and Greece demonstrated their initial documented use of sunlight by burning mirrors to light torches for spiritual functions. Ancient architectural designs in Rome and Greece utilized passive solar design i.e. the utilization of sunlight to heat and light indoor areas. This system still remains until today as one of the foremost economical in which to use the alternative energy. This was taken a step additionally and mica was used to cover south facing buildings to trap the warmth.

A jump in time to the Ninetieth century shows great advancements in technology and different needs to tap sunlight to useful work. The history of alternative solar energy hence, demonstrates advancements in solar technologies comparing to changes in human energy demand. With environmental conditions and depletion, and cost of fossil fuels, today’s world perpetually strives for the most effective technically and economically feasible way to use definitely the greatest natural resource – the sun.

In 1839 French scientist Edmond Becquerel astonishingly at the age of nineteen years discovers the photovoltaic effect while experimenting with an electrolytic cell made up of two metal electrodes (Platinum) placed in an electricity-conducting solution where electricity-generation increased once exposed to Direct Sun light. Also he discovered different colours and different types of light had produced different effects on producing power. Best results he obtained from Blue lights and Ultra violet coloured lights. Even he tested with Coating of various materials over the electrode. He obtained Silver Chloride AgCl or Silver Bromide AgBr coating produces maximum efficiency.

01-Edmond Becquerel- photovoltaic effect setup- first photo electricity generation method

In 1860s French mathematician August Mouchet proposed an idea for solar-powered steam engines. In that project, solar energy could be used to power engines to do tasks such as Ice making. He coupled steam engine to his refrigeration device where steam engine power got from sun. In the following 20 years, he and his assistant, Abel Pifre, designed the first solar powered engines and used them for a variety of applications. These engines became the forerunner of modern parabolic dish collectors.

01-solar powered steam engine

In 1873 Willoughby Smith an electrical engineer of UK and his assistant Joseph May discovered the photoconductivity of selenium (Se). The electrical resistance properties varied (decreased) dramatically with the amount of light (increase intensity of incident light) falling on it. This concept is used for converting images into electrical signals, which is the basis for yesteryears television system. He also tested the conductivity properties of Selenium, which is exposed to light.

01-selenium (Se) Wafers - Selenium Rod

In 1877 William Grylls Adams and his student Richard Evans Day of UK discovered that selenium produces electricity once exposed to light. In spite of selenium solar cells failed in their attempt to convert enough sunlight to power (1 to 2 percentage efficiency) the electrical equipment, they verified that a solid material may change the light into electricity without heat or moving elements. Until 1970, Selenium cell properties used for very low power applications such as photographic exposure meter.

01-Selenium (Se) Glass tube - Adams and Day Photoconductivity setup

History Of Solar Energy | Solar Thermal History

The sun has made energy for billions of years.  Solar energy is that the sun’s rays (solar radiation) that reach the world. Solar power technology isn’t new. Solar energy history spans from early mankind’s to nowadays. Solar energy is employed everywhere in the planet in several aspects. Solar Energy is a renewable source because it isn’t made of fossil fuels and it’s made naturally. Additionally we will never run out of solar energy because the sun is often there. Today, we’ve everything from solar-powered homes to solar charged automotives.

In fifteenth century B.C. Egyptian ruler Amenkotep III had “sounding statues” that emitted a tone once air inside was heated by the radiated sun rays.

01-Egyptian ruler Amenkotep III  sounding statues

In the early seventh Century B.C. magnifying glasses are accustomed to concentrate sun’s rays to create fire which are used for lot of reasons. These light rays are accustomed to burn ants. Early days the people stored the wheat’s for long days which are attacked by ants. So that they killed the insects by light rays.

01-magnifying glasses to burn ants

Around third Century B.C. Greeks and Romans use burning mirrors (burning mirror fabricated by joining triangular metal mirrors) to light torches for spiritual purposes.

In Second Century B.C., (212 B.C) the Greek scientist, Archimedes, used the reflective properties of bronze shields (large number of angled hexagonal mirrors) to focus sunlight and to set fire to wooden ships of roman empires. (Although no proof of such a effort / feat exists) (The Greek navy re-created this experiment in 1973 and successfully set fire to a wooden boat at a distance of 50 meters.)

01-archimedes hexagonal mirrors

In twentieth century A.D. Chinese uses the burning mirrors (Bronze Concave Mirrors) to light torches for spiritual purposes and for cooking.

01-chinese burning mirrors

From first to fourth Century A.D. The famous Roman bathhouses had massive south facing windows to let in the sun’s rays to warmth the swimming pools. The sketch books of Leonardo da Vinci architect shows that the great Italian hoped to comprehend his solar ambitions by the use of burning mirrors. He planned to make one solar concentring mirrors with a radius of half a mile to heat the water for swimming pools.


Around 1200s A.D. Ancestors of Pueblo people called as Anasazi in North America (Pre Columbian natives) (who are the hunters begin to do agricultures stayed in one place for several years) board in south-facing cliff dwellings to capture the winter sun. They built 18 to 24 inches thick walls fabricated from cement, sand and water, which absorbs the winter sun’s heat energy and the stored radiant energy which keeps the heat balance during nights. These are the earliest passive solar designs.

01-south facing cliff dwellings of Ancestors of Pueblo people called as Anasazi

In 1767 Swiss scientist Horace de Saussure was attributed with building the world’s first solar collector hot boxes fabricated from wood with glass covers which trapped the sun rays energy (Heat produced nearly 320 deg F), later the concept is used by Sir John Herschel to cook food (reached a temperature of 240 deg F) during his South Africa expedition around 1830s. Saussure also invented the helio-thermometer (1767), an instrument for measuring solar radiation. This instrument was a basic to modern solar radiation measurement devices.

01-Saussure solar collector hot box

In 1816 Robert Stirling of Scotland who sought to create a safer alternative system to the steam engines. Before that steam engine boilers are exploded due to the high pressure of steam. So he developed an Economizer for the engine to prevent from high pressure. He applied a patent for his Refrigerator or Economizer. This engine was later used in the solar dish / Stirling system, which is connected to grid system that concentrates the sun’s thermal energy to a single focus points so as to supply / produce power.

01-solar dish stirling engine - stirling cycle - stirling engine