Solar panel buyers guide 2014

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We’ve contacted photovoltaics manufacturers for details on warranties, cell types, size and price to help you decide which solar panels are best for you.

Solar photovoltaic (PV) panels have a range of uses from powerful grid-interactive or off-grid rooftop installations to small DIY applications such as for camping or pumping water.

Over the last few years, grid-interactive rooftop installations have emerged as the most popular use of PV in Australia. Well over a million homes are now enjoying reductions in their electricity bills. Worldwide, demand from rooftop systems and solar farms has produced economies of scale leading to significant reductions in panel prices, especially for the larger panels used in such applications.

A solar installation consists of several components, depending on the application. This guide focuses on panels. For information on other components, system sizing and economic returns, see ‘More info’ at the end of the article.

How solar cells work
Solar cells produce DC electricity, similar to that from a battery. The amount of current produced by a panel of cells is proportional to the amount of light hitting the panel.

The basic mechanism of operation for a solar cell is as follows.

A solar cell is made of a thin slice of a material such as silicon. The silicon is modified by a process called doping with elements like boron and phosphorus to form what’s called a semiconductor P-N (positive-negative) junction inside the cell.

As photons in light strike the solar cell, they cause electrons (electrically negative sub-atomic particles) to cross the P-N junction, causing a voltage across the junction.

By connecting a load from one side of the cell to the other, the electrons will flow through the load, allowing the electrons to be harvested as an electric current.

The different technologies
A typical solar cell only produces around half a volt, which is too low to be of much use. Photovoltaic panels are made of a group of solar cells, usually with the cells connected in series to produce a much higher, usable voltage. There are three common types of solar cells: monocrystalline, polycrystalline and thin film.

Read the full article in ReNew 126

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