Energy from the sun

The sun bathes our plant with a huge amount of energy, about 85,000 terawatts, each year. Our annual consumption of energy, by comparison is only about 16 terawatts. This means that the sun provides about 5,000 times more energy than the world needs today. It seems silly, Therefore, that we are polluting our planet by burning fossil fuels where as so much abundant energy from the sun is largely going waste. This situation is now beginning to change rapidly and new technologies are emerging that the country where is shortage of electricity needs to make use of.

Solar cells are normally made of silicon wafers. These crystal line materials have achieved a commercial efficiency of 22 percent but the solar panels made from them are expensive. and largely suitable for remote areas where the grid system can not provide cheaper electricity. Thin-film solar cells produced from amorphous, nano-crystalline and some other form of silicon by chemical vapor deposition, have efficiencies of about nine percent, but they can be produced at one-fifth the cost and their efficiencies are improving rapidly.

However the most attractive form of solar energy involves the simple use of thousand of mirrors that can focus the energy of the sun on boilers located on towers. The steam generated by this energy from this 'Concentrating solar power' (CST) technology is heated to a temperature of up to 850 Fahrenheit, and used to drive turbines that generate electricity.

Google has funded a five megawatt facility near Los Angeles that involves 24,000 mirrors arranged in arrays on 20 acres of land. They are controlled by computers that focus the sun light on to the boilers. It is expected that the use of CST technology will double energy 16 months worldwide, increasing from 457 megawatts in 2007 to 6,400 megawatts by 2012.

The countries that have abundant sunshine and an acute shortage of electricity must use it.