Thursday, February 11, 2010

Types of solar cell

Solar Cells

Solar cells are usually made from silicon, the same material used for transistors and integrated circuits. The silicon is treated or "doped" so that when light strikes it electrons are released, so generating an electric current. There are three basic types of solar cell. Monocrystalline cells are cut from a silicon ingot grown from a single large crystal of silicon whilst polycrystalline cells are cut from an ingot made up of many smaller crystals. The third type is the amorphous or thin-film solar cell.

Amorphous Solar Cells

Amorphous technology is most often seen in small solar panels, such as those in calculators or garden lamps, although amorphous panels are increasingly used in larger applications. They are made by depositing a thin film of silicon onto a sheet of another material such as steel. The panel is formed as one piece and the individual cells are not as visible as in other types.Amorphous solar panel

The efficiency of amorphous solar panels is not as high as those made from individual solar cells, although this has improved over recent years to the point where they can be seen as a practical alternative to panels made with crystalline cells. Their great advantage lies in their relatively low cost per Watt of power generated. This can be offset, however, by their lower power density; more panels are needed for the same power output and therefore more space is taken up.

Crystalline Solar Cells

Panel made of individual solar cells Crystalline solar cells are wired in series to produce solar panels. As each cell produces a voltage of between 0.5 and 0.6 Volts, 36 cells are needed to produce an open-circuit voltage of about 20 Volts. This is sufficient to charge a 12 Volt battery under most conditions.

Although the theoretical efficiency of monocrystalline cells is slightly higher than that of polycrystalline cells, there is little practical difference in performance. Crystalline cells generally have a longer lifetime than the amorphous variety.


Mulai Januari 2010, Kerajaan Negeri Selangor melaksanakan kempen "Hari Tanpa Beg Plastik" setiap hari Sabtu bagi mengurangkan penggunaan beg plastik. Sesiapa yang masih ingin memohon beg plastik akan dikenakan bayaran 20 sen sehelai.

“Kempen Tanpa Penggunaan Beg Plastik di Negeri Selangor” akan dilaksanakan mengikut peringkat yang dirangka memakan masa selama dua tahun. Sehubungan dengan itu, peringkat yang pertama adalah dengan melaksanakan kempen“ Hari Tanpa Beg Plastik” pada setiap hari Sabtu akan bermula pada tahun awal Tahun 2010. Setelah perlaksanaan kempen dilaksanakan selama 6 bulan, pihak Kerajaan Negeri bersama pengusaha-pengusaha akan menjalankan pemantauan bagi mengenalpasti impak daripada kempen tersebut. Sekiranya kempen ini membawa kepada satu impak yang positif, perlaksanaan peringkat kedua diteruskan dengan melanjutkan kempen “Hari Tanpa Beg Plastik’ kepada hari-hari biasa.

Press Statement: Januari 2010

Based on a study done in 2009, around 8 billion plastic bags have been used in Malaysia. Being the most populated and urbanised state in the country, we can assume that Selangor is a major contributor to that statistic. That is why the state government initiated the “No Plastic Bag Day” campaign. We are targeting a 20% reduction in the usage of plastic bags within 6 months.

For the first three months of the campaign, January to March, we will focus mainly on educating consumers and expanding retailer participation. Following that, we will consider making participation a licensing condition and study the possibility of increasing the frequency of the “No Plastic Bag Day” per week.

We are happy to announce that the number of participating retailers and malls have increased to 25 from the initial 12. Many more have also expressed interest and we are in the midst of finalising their participation.

The state government will also be meeting the Malaysian Retailers Association, Malaysian Retailer-Chains Association and Malaysian Plastic Manufacturer Association to get their support for the campaign.

The Selangor state government takes the campaign very seriously. We have received reports of participants in the campaign that are not fully compliant of the agreement. While we understand that some teething problems are inevitable, we urge all participants who wish to remain part of the campaign to adhere to the agreed-upon conditions, including the 20 sen charge for each plastic bag.

Finally, in order to propagate this campaign effectively, the state government has created a Web site for the public to get more information. Campaign materials in all major languages are available on the site, while retailers interested in participating in the campaign can download the declaration form as well.

Web site URL:
Telephone number: 03-55447760
Fax number: 03-55193328

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