Solar Powered Lights

By Idelle, July 10, 2008

Owning an older home, we have a lack of electrical sources. We’ve been slowly adding new outlets inside our home, but haven’t yet had a chance to add many outside. So when it came to choosing lights for outside, I consider solar lights – these are lights powered by the sun. There are a lot of options available – and not all solar lights are bright enough for my liking. I find that using reviews on Amazon are a good way to find out which lights are brightest and longest lasting. Check out the ones on this page which had very good reviews. There are a lot of advantages to solar powered lights – they don’t cost to use, they can be placed in areas without an electric outlet or source, and many feature automatic on/off features so you don’t have to switch them on and off.

The History of Solar Power

Solar power technology isn’t new. Its history spans all the way back to the 7th century B.C., when a magnifying glass was used to concentrate sun’s rays to make fire. In the 3rd century B.C., Greeks and Romans used burning mirrors to light religious torches, and in the 2nd century B.C., a Greek scientist, Archimedes, used highly reflective bronze shields to focus sunlight and to set fire to wooden ships from the Roman Empire which were besieging Syracuse. Closer to the present, in Rome during the 6th century A.D., people were commonly building sunrooms on houses and public buildings, and they thought so much of their sunlight that “sun rights” were protected under the Justinian Code to ensure individual access to the sun. During the 1200s the North American ancestors of Pueblo people called Anasazi in built their cliff dwellings to capture the winter sun for warmth.

The world’s first solar collector was created by a Swiss scientist named Horace de Saussure. This solar collector was later used by Sir John Herschel to cook food during his 1930s expedition to South Africa. On September 27, 1816, a man named Robert Stirling applied for a patent for his economiser at the Chancery in Edinburgh, Scotland. Lord Kelvin used one of the working models during some of his university classes. This engine was later used in the dish/Stirling system, a solar thermal electric technology that concentrates the sun’s thermal energy in order to produce power.

Then in 1839, a French scientist named Edmond Becquerel discovered electricity-generation while experimenting with the the photovoltaic effect using an electrolytic cell made up of two metal electrodes, immersed in an electricity-conducting solution that increased electricity production when exposed to light. The next step was in 1873 when Willoughby Smith discovered that selenium possessed photoconductivity. Quickly following this in 1876 William Grylls Adams and Richard Evans Day discover that selenium produces electricity when exposed to light. Although they failed to actually power electrical equipment, this did prove that a solid material could change light into energy.

In 1891, Baltimore inventor Clarence Kemp patented the first commercial solar
water heater. During the early 1900s, scientists continue to find other photosensitive materials such as copper and cuprous oxide, copper coils, and finally single-crystal silicon in 1918 by a Polish scientist, Jan Czochralski. In 1921 Albert Einsein gives his nod to solar energy and wins the Nobel Prize for his theories explaining the photoelectric effect.

In 1947, passive solar buildings were in high demand in the United States, due to the scarcity of energy during WWII. A book titled Your Solar House featured 49 of the nation’s finest solar architects.

In 1954, Photovoltaic technology is discovered when American Bell Labs scientists develop the silicon photovoltaic (PV) cell — the first solar cell capable of charging and running everyday electrical equipment. The solar cell had just 4% efficiency. At this time, solar panels were not commercially available, and were very expensive. In 1955, Western Electric gets in the market by selling licenses for PV (photovoltaic) technology, and products start to hit the market such as PV-powered dollar bill changers. Continuing in the 1950s architects start using solar water heating, and solar heated buildings and satellites, while continuing to increase efficiency and radiation resistancy of photovoltaic cells.

During the first years after the discovery of the silicon solar cell, the cost of solar cells was prohibitive. Desperate to find commercial outlets for solar cells, novelty items such as toys and radios run by solar cells were manufactured and sold.

The “Space Race” provided some funding for solar research and development. In NASA launched the first Nimbus spacecraft, powered by a 470-watt PV array. The new technology to power these spacecrafts were, expensive, some of NASA’s early panels were over $30,000 per watt.

The 1970s were the dawn of commericially affordable solar power. Exxon and Dr. Elliot Berman design a cheaper solar cell, bringing the price from $100 a watt to $20 a watt – making solar cells much more affordable to the masses. Railroads, lighthouses, gas and oil rigs, warning lights and other remote area applications began to use solar cells for power.

In the 1980s solar power worldwide production increases from 1 megawatt to over 20 megawatts, and efficiency increases to 20% in 1985 at the University of South Wales. 1986, along with hairspray, faded jeans and neons, brings the world’s largest solar thermal facity to Kramer Junction, California. In 1991, President George Bush changes the U.S. Department of Energy’s Solar ENergy Research Institute as the National Renewable Energy Laboratory (NREL), which in turn constructs an energy-efficient “Solar Energy Research Facility” using a solar electric system and passive solar design.

In 1994, the NREL develops a solar cell that exceeds 30% efficiency. In 1996, the Icare, an airplane covered with 3,000
super-efficient solar cells, flies over Germany. In 1998, Subhendu Guha, a noted scientist for his pioneering work in amorphous silicon, led the invention of flexible solar shingles.

In Ohio in the year 2000, First Solar begins production at the world’s largest photovoltaic manufacturing plant producing enough solar panels each year to generate 100 megawatts of power. And Home Depot begins selling residential solar power systems in their stores.

Continuing in the 2000s to the present, companies are decreasing the costs of solar panels, and increasing efficiency. In 2002, Japan installed 25,000 solar rooftops. In 2006, the U.S. Department of Energy funded the production of a concentrator solar cell by Boeing-Spectrolab which achieved a world-record conversion efficiency of 40.7 percent, establishing a new milestone. At 40% efficiency, the land area needed to supply the entire world of it’s energy needs would be roughly 265 square miles – and considering Colorado alone is 104,100 square miles in size – that isn’t very large! Just supplying the USA would take about 25% of that land area. Amazing.

So – now time will tell. As the cost of solar power decreases and efficiency increases, we are nearing a point in which solar energy costs will equal that of coal, oil and gas – and will likely revolutionize our energy industry. Can’t wait! Blue skies ahead!

This post is sponsored by Outdoor Solar Store providing solar powered lights and more!
www.outdoorsolarstore.com

Sources:
www1.eere.energy.gov
www.norcalblogs.com
www.solarenergygreenlifestyleforyou.com