Solar Electric Panels - Photovoltaic cells

"The sun delivers 219,000 billion kilowatt hours of energy every year to the earth – more than 2,500 times more than the total world population currently uses." Sharp Website

The development of solar panels, like so many forms of renewable energy has been around far longer than most of us realise. Solar panels are made up of photovoltaic cells which when the sun shines on them, produce usable electricity. They work because a photovoltaic cell is made up of different elements, most notably silicon. When sun rays strike the panel it excites the elements in the panel and electricity is produced.

The obvious drawback of a solar panel system is what happens when the sun is not shining? On a dull day the sunlight is greatly reduce, however even in these conditions solar panels will generate a small amount of power. At night though power generation ceases. To counter this, a solar system is designed to contain a battery pack which stores energy as it is produced. Generally, the battery system will be designed to cope with the demand requirement for as long as possible or what may be considered a reasonable time before the next charging period is likely to arrive.

Electricity from the solar panel comes out as D.C. (direct current) whereas your home or workplace is A.C (alternating current). To turn D.C. into A.C., electricity is then taken from the panel via wires to a device called an inverter where it is converted. The D.C. current can be used to directly from the panels to charge your batteries as they are D.C. but to avoid the batteries being overcharged, a charge controller needs fitting. The charge controller smoothes the supply from the panel so that the batteries do not get burnt out if the sun happens to get particularly strong. The controller also turns off the supply to the batteries once they are fully charged.

Solar panels have seen some great advances over the last fifty years. Initially they could convert about 3% of the energy they were receiving from the sun into useable electricity. Nowadays however, the conversion is nearing 30% and the cost of producing the panels has also dropped dramatically. With the oil prices spiralling, solar panels are now looking a better alternative form of power than they were 10 years or so ago.

Solar panels have yet to fully discover there full potential. Imagine a house not built with bricks and tiles but from sheets made of photovoltaic cells. This has the benefit when used in building new homes of cutting the cost of the electricity generated. You would of had to have paid for the materials to build the house and then pay further for the panels. In effect, you end up building two sets of wall or roof which is obviously not just wasteful but is financially unsound. Roof tiles have already been developed incorporating solar cells and it is not unknown for houses that are roofed with such to be selling excess power back to the electricity grid. The system is still currently quite an expense but as with such new ideas, the cost is continually falling.

Let's not forget that solar panels are not just limited to generating power for our household appliances. Starting with the humble pocket calculator which has been around for many years with its solar cell able to do away with batteries. It is now commonplace to see road signs using solar power which negates the expense of having to lay expensive wiring to remote situations. Data transmissions from remote locations are now possible again thanks to the affordability of modern panels. There is quite an intense competition going on all the time to produce solar powered vehicles at the  World Solar Challenge  and the 3000 kilometre race continually attracts major car manufacturers as well as independent engineers and research institutions. There are several small vehicle applications fitted with solar panels now to assist in their running, golf carts being a prime example.

As more and more devices use solar panels, it all adds up to relieving the use of fossil fuels. Solar panels have a unique feature in that compared to water power or wind, they can be compact enough to power low use applications and thus their continued use will only increase especially as the panels themselves are still developing to higher standards and outputs.