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Solar power,
energy from the sun

We‘ve used the Sun for drying clothes and food for thousands of years, but only recently have we been able to use it for generating power.

The Sun is 150 million kilometres away, and amazingly powerful.

Just the tiny fraction of the Sun‘s energy that hits the Earth (around a hundredth of a millionth of a percent) is enough to meet all our power needs many times over.

In fact, every minute, enough energy arrives at the Earth to meet our demands for a whole year - if only we could harness it properly.

1. Solar Cells (really called "photovoltaic" or "photoelectric" cells) that convert light directly into electricity.
In a sunny climate, you can get enough power to run a 100W light bulb from just one square metre of solar panel.
This was originally developed in order to provide electricity for satellites, but these days many of us own calculators powered by solar cells.

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2. Solar water heating, where heat from the Sun is used to heat water in glass panels on your roof.
This means you don‘t need to use so much gas or electricity to heat your water at home.
This helps out your central heating system, and cuts your fuel bills.
However, in the UK you must remember to drain the water out to stop the panels freezing in the winter.
Solar heating is worthwhile in places like California and Australia, where you get lots of sunshine.

 

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3. Solar Furnaces use a huge array of mirrors to concentrate the Sun‘s energy into a small space and produce very high temperatures.
There‘s one at Odellio, in France, used for scientific experiments.
It can achieve temperatures up to 33,000 degrees Celsius.

 

 

 

More details
Solar Cells provide the energy to run satellites that oribt the Earth. These give us satellite TV, telephones, navigation, weather forecasting, the internet and all manner of other facilities

One idea that is being considered is to build solar towers.

The idea is very simple - you build a big greenhouse, which is warmed by the Sun. In the middle of the greenhouse you put a very tall tower. The hot air from the greenhouse will rise up this tower, fast - and can drive turbines along the way. This could generate significant amounts of power, especially in countries where there is a lot of sunshine and a lot of room, such as Australia.

Advantages

* Solar energy is free - it needs no fuel and produces no waste or pollution.

* In sunny countries, solar power can be used where there is no easy way to get electricity to a remote place.

* Handy for low-power uses such as solar powered garden lights and battery chargers

Disadvantages

* Doesn‘t work at night.

* Very expensive to build solar power stations.
Solar cells cost a great deal compared to the amount of electricity they‘ll produce in their lifetime.

* Can be unreliable unless you‘re in a very sunny climate.
In the United Kingdom, solar power isn‘t much use except for low-power applications, as you need a very large area of solar panels to get a decent amount of power. However, for these applications it‘s definitely worthwhile.

Article source: darvill.clara.net