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Electricity: Generation and Transmission

Devon Nicholson

Electricity, something we use in our everyday life, it has practically become a necessity for many of us. But have you ever wondered how it is created? The different ways that it is created? There are so many ways that electricity is made across the globe from hydroelectric power plants to nuclear power plants.

 

Put as simple as possible, hydroelectric dams are a power plant that converts falling water into energy that we can use. But it isn’t as simple as that though, let’s start out with the main parts needed for the dam, so that we better understand the process.

In a hydroelectric dam there is, a reservoir, a dam, a penstock (pipe), a turbine, a generator, and transmission lines so the energy can be transported to our homes.

All the water starts in a reservoir, usually a lake, and await being used. This water may be a natural or unnatural water source. When some off the water is ready to be used it travels down a penstock, which is a large pipe that leads the water to the turbine. The turbine is like a small windmill that spins from the water pushing against it. It changes kinetic energy into mechanical energy and is sent off to the generator. The generator has magnets inside that spin, causing the mechanical energy to convert into electrical energy. The energy is then moved to transmission lines and is sent to our homes. And the water that was use is sent out the other way into a river.

Photo Credits to: http://www.ellenvaritimos.com/wp-content/uploads/2012/02/Hyrdoelectric-Power.png

http://www.conserve-energy-future.com/pros-and-cons-of-hydroelectric-power.php http://www.wvic.com/content/how_hydropower_works.cfm

 

Thermal power plants, convert high pressure and high temperature steam into electricity for us to use. But this steam doesn’t just appear out of nowhere, it is actually quite a long process. Let’s start out with parts of this power plant.

In a thermal power plant there are many parts, coal, a stacker, a conveyor, bunkers, feeders, polarizers, fans, a boiler, turbines, a generator, a condenser, and a cooling tower that all have important roles in this process.

It all starts out with coal. Millions of pieces of coal are stored away in piles, waiting to be used. When finally ready, a stacker dumps it into a conveyor. The conveyor will then move it all to bunkers where it will once again await being used. After waiting a possible 30 hours the coal will move to a feeder, which will feed it to polarizer. The polarizer is a machine with a large drum in the inside. The drums spins causing the coal to turn into a thin powder and is moved towards the boiler area. Giant fans add warm air that push the powdered coal into the boiler. The boiler has miles of pipes filled with water in it. The coal will enter the boiler and will be ignited which releases energy. As well as changes the water in the tubes into 1000°F steam. The steam is pushed through a series of turbines which converts thermal energy into mechanical energy. Just as in the hydroelectric power plant, the generators magnets spin converting mechanical energy into electrical energy.

But it’s not quite over yet. The unused steam is then exhausted into the condenser. The condenser is the machine that takes all that excess steam and turns it back into water. There are pipes all around the condenser filled with cold water. Steam passes over the water filled pipe, which turns to steam into water. The warm water must then move to a cooling tower to chill it once again. Once the water is cold again it is sent back to the boiler to be reused, this process is continuous.

Photo Credits to: http://medafricatimes.com/6170-zimbambwe-china-to-build-1-1bn-thermal-power-plant.html

https://www.youtube.com/watch?v=xokHLFE96h8

http://lifestyle.iloveindia.com/lounge/pros-and-cons-of-thermal-power-13991.html

So which of these two power plants are best for us? They both have their benefits and disadvantages that could affect us. Let’s start out with the thermal and move to hydroelectric.

Thermal power plants are easy to supply as the resource are hard to find. It opens tons of employment. The plant can practically be placed anywhere because there are no specific requirements. Plus it produces a lot more energy for us to use. As nice as all these things seem there are some cons that go along with it. Pollution is a big factor, all these gases are let into our breathing air. It is very expensive to run as you need lots of employees. The resource needed are not renewable for future use. It is not always dependable in some cases. Some of the waste disposal created by the power plant is going into our ocean or land.

Hydroelectric power plants are a very effective way for us to get electricity in our homes, but is it a good idea? The energy is reusable to use later on if needed. It is a great tourist attraction, I know from personal experience the hydroelectric dam that had gondolas had many tourists. It is eco-friendly as it reduces the carbon emission into the air. It has a general low operating cost. The lake could be used for recreational reasons, which could be advantage. All these advantages sound so great, but are there cons? Yes. This dam is incredibly expensive to build, way too much. Marine animals such as fish could die because the dam blocks the migration. Is ruins our environment and the beauty of nature. A drought could ruin the dam, so that no one would get electricity. And in a case of lots of raining it could flood and cause lots of destruction.

 

Notes for transmission:

• Starts at power plant
  • Sent to transformer to increase voltage
    • Flow through long transmission lines
      • Reaches a substation, voltage lowered and sent on smaller lines
        • Reaches another local substation and can now be in neighbourhood
          • Must lower voltage through pole or pad transformers
            • Meter base attaches to house
              • Electricity travels through base into home

Step up transformers:

• Transformers that increase voltage so that the electricity can travel farther to reach our homes.

Step down transformers:

• Decreases the amount of voltage so the electricity can safely travel to other areas

 

 

Some may think that electricity just magically arrives at your home, but I am going to let you in a little secret, it doesn’t. Electricity sometimes has to travel miles just for you to be able to use it. Electricity is transmitted through electrical transmissions, which are set up everywhere.

The electricity starts in the power plants and from there starts it journey. It must go through step up transformers that make the voltage increase to 500 000 kv so it can travel farther. Then it must travel down electrical transmission lines until it is able to turn off. The voltage will be lowered by a step down transformer from 60 kv to 138 kv and sent off onto smaller lines. But still the voltage is too high, so it must go to the neighbourly substation. Now the electricity can travel through your neighbourhood. But it still has a voltage too high for your home. It must be decreased on a pole mounted transformer or a pad mounted transformer to 25 kv. There are lines attached to your house called service drop, which takes the safe energy into your home. The knob which holds the wires to your home is attached to weather head which prevents water or rain getting into the electrical meter. The electricity travels through the electrical meter into your home for you to use.

http://www.alliantenergykids.com/EnergyBasics/AllAboutElectricity/000416

 

You see, electricity is magic that is created by itself for us. It is made by different power plants and transported to our homes via electrical transmission lines. As you read above about the benefits and disadvantages, so which of these power plants. In my opinion, hydroelectricity would be the best choice. It has more useful advantages and it isn’t polluting our air. Who knows though, maybe in the future there will be a new no-pollution power plant for us to use.