Sunday, August 26, 2012

Solar cell facts

A solar cell is an electrical device that converts the energy of light directly into electricity by the photovoltaic effect. A solar cell is also called photovoltaic cell or photoelectric cell.

Photoelectric effect was first observed 1839 by Edmond Becquerel, a physicist from France. In year 1876 Adams and Day observed the photovoltaic effect in solid selenium.  Modern solar cell was discovered in 1954. Bell Labs researchers Pearson, Chapin, and Fuller reported their discovery of 4.5% efficient silicon solar cells; this was raised to 6% only a few months later.

A solar panel is a packaged, connected assembly of photovoltaic cells. Solar panel is also called solar module, photovoltaic module or photovoltaic panel. Photovoltaic solar power plant is an array of many connected solar panels.
Solar panel (PV panel).
Efficiency of solar cells is increasing, and current efficiency for solar cells (panels) on retail market is somewhere between 18 and 24 percent.  Recent research projects achieved efficiency of 43% in laboratory conditions, which is very near to 50% - goal set by the Defense Advanced Research Projects Agency.

Although general and special theory of relativity are most important and famous work of Albert Einstein, in 1921 he received his only Nobel Price "for his services to theoretical physics and especially for his discovery of the law of the photoelectric effect" (work from 1905).

In last few years solar cell production is shifting from western countries to the east because of low-labor-cost countries in Asia, especially China.  Last available data from 2011 says that eight out of ten largest producers are located in Asia; six of them are from China. This is huge expansion of solar cells production in China because in 2008 only 33 percent of solar cells were made in China, a share that grew to an impressive over 57 percent in 2011.

Charanka Solar Park in India is the largest photovoltaic solar power plant in the world with 214MW in production in April 2012 and growing to expected 500MW in year 2014. Agua Caliente Solar Project in Arizona, US, is the second largest photovoltaic solar power plant in the world with more than 200MW in production in June 2012 and growing to expected 290MW (AC) until year 2014. We can compare this also to average capacity of nuclear power plant which is 846MW in US.
Charanka Solar Park in India. This is largest PV solar plant in the world.
Solar cells have limited lifespan, as any other electronic based technology. Solar cell panels are expected to function for a period of 30 to 35 years. The typical warranty given by panel manufacturers is over 90% of rated output for the first 10 years, and over 80% for the second 10 years.

At the end of 2011 Germany was the world leader in installed capacity of photovoltaic solar power with installed 24,700MW peak power capacity. Italy is second with 12,500MW installed. Third is Japan with 4,700MW. Fourth place share United States and Spain, each with 4,200MW installed. World total installed capacity at the end of 2011 was around 68,000MW.

Despite of relatively bad geographic location, solar PV in Germany provided 18 TWh of electricity in 2011, which is about 3% of total electricity generated in country. Geographic position of the United States is much better, but lack of investment into solar PV power resulted with only 3.8TWh of generated electricity in 2011, which is less than 0.1% of US electricity production.

Market analysts expect that Germany will reach 25 percent of solar PV generated electricity in total electricity generated by 2050. In combination with other renewable energy sources this would be huge step into 100% clean electricity production era.

1 comment:

Aadon Jones said...

Solar cells are very useful for powering space vehicles such as satellites and telescopes. Cells provide a very economical and reliable way of powering objects. Thanks!
Solar Panel