It is often said that a journey of a thousand miles begins with a step, but have you ever wondered what it is like, the first step of the journey that brings our guest, Mr. Electricity to our homes? Today electricity has become such an integral part of our lives to the extent that we become so uncomfortable when there is a power blackout for a few minutes. We plug our mobile phone chargers, computers, home theatre sets etc. into the wall sockets and these devices start working. We turn on the switch on the wall and our rooms are illuminated, but do we ever wonder how the electricity gets into the ‘wall’? Indeed, in Ghana we have a fair idea our electricity comes from the Akosombo dam because whenever there is a power crisis we hear several complains about the reduction in water level in the dam, but how exactly is water able to do the trick and how does the electricity travel all the way from its source to our homes?

Electricity is generated at a power station. A power station is a structure that houses motors consisting of giant magnets and an armature (framework) of coiled wire. At the power station, some form of mechanical energy is needed to power the motor in order to cause the coiled wire to rotate. This is achieved through the rotation of a turbine. A turbine is a form of engine, for purposes of illustration, likened to our car engines which convert chemical energy in petrol or diesel to mechanical energy which causes the car to move forward. The turbines at power stations convert energy from a moving stream of water, steam or gas into mechanical energy which causes the coiled wire to rotate through a magnetic field created by the magnets. The motion of the wire through the magnetic field induces electric charges into the wire. A voltage is created across the wire, which in turn causes electric current to flow through the wire, when in a circuit.

The electricity generated at a power station is of very high voltage (pressure) i.e. about 756,000 Volts, which if allowed into our communities will blow up our homes. It is transported through high tension cables (pylons) to substations to be distributed and also stepped down (reduced to lower levels) using transformers to about 240 Volts which is safe for our computers, washing machines etc.

The Akosombo dam is referred to as a hydro-electric power station because water pours from the dam to power the turbines which generate electricity. You might have also heard of the Takoradi Thermal Power Station (Aboadze Thermal Plant). This is also a power station which generates electricity to supplement the one from the Akosombo dam. At the thermal plant, thermal (heat) energy from steam is used to power the motors which generate electricity. The steam is produced by boilers which also run on fossil fuels i.e. coal, diesel, natural gas etc. These sources, however are relatively costly and also contribute largely to global warming. Subsequent articles will further give details on how these sources generate electricity.

Further reading:

 Microsoft ® Encarta ® 2009


Posted on September 15, 2012, in Technology and tagged , , , , , , , , . Bookmark the permalink. 1 Comment.

  1. Electricity has become such an essential part of life … let’s conserve it. You can add your views too

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