Tuesday, October 23, 2012

What Is Photovoltaic Energy?



Miss conceptual of "solar energy"

Layman speaking, we always referred “solar thermal energy” or “photovoltaic energy” both as “solar energy”. Technically, what is the different? The common use of “solar thermal energy” in Malaysia is to heat water. Solar thermal water heater consists vacuum tubes or panels attached to an insulated water tank. The familiar look of the system is shown below.
What is photovoltaic?

Photovoltaic panel looks similar to the solar panel used in the solar water heater but they work in a different way. Photovoltaic panels convert sunlight directly into electricity. Photovoltaic systems have been developed to provide electricity in remote area. The system can be used to pump water from well, to power light to replace candle and kerosene lamp. In daytime the panel will charge a storage system, mostly batteries. The batteries then power the light at night or the pump in cloudy or rainy day.

History of photovoltaic

First used in about 1890, the word “photovoltaic" has two parts: photo, derived from the Greek word for light, and volt, relating to electricity pioneer Alessandro Volta. In 1839, French scientist Becquerel discovered the process of using sunlight to produce electricity in a solid material. But it took more than a century to truly understand this process. Scientists eventually learned that the photoelectric or photovoltaic effect caused certain materials to convert light energy into electrical energy at the atomic level.

Photovoltaic materials

Silicon is the common material to build photovoltaic panel. It is a material known as a semiconductor. Silicon dominates 80 to 90% of the photovoltaic market. Following pictures show you how the panels looked like.
Silicon photovoltaic panels can last you more than 20 years with only some power degradation. Common degradation is about 1% power drop per year. Recent study shows some panels maintain more than 90% of their original rated power even after 20 years of operation.

Malaysia government photovoltaic program

Malaysia government has launched a renewable energy feed-in-tariff program in Dec. 2011 where TNB and SESB will buy back the energy generated from clean energy source at much higher rate. For photovoltaic energy, the rate is as high as RM1.75 per kWh. Sad thing is that the program has not been implemented in Sabah yet pending on the discussion of Federal energy authority, SEDA, SESB and Sabah government.

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