Using Water to Create Electricity
Posted - 1/6/2016 2:54 PM by Dan B.
Have you noticed how dependent upon electricity we are? The alarm that wakes us up in the morning requires electricity, so do the lights that keep us from walking into walls and the air conditioning that keeps us cool on a hot summer day. Electricity keeps our fridges running so our food doesn't spoil, it keeps our TV's running so we don't get bored and it charges our mobile devices so we can constantly stay in contact. The list could go on and on!
What happens to make your lights come on inside your home? How is electricity created, stored and transferred? These are great questions, thank you for asking! This is what we will be discussing; how it is that man creates the powerful electricity that we depend on so much.
The many ways we create electricity
There are many different ways to produce electricity. The technology created to generate and harvest a natural source like electricity is outstanding and it will only continue to get better. Some people have electricity generated by power plants that burn coal. This causes steam to rise and force turbines to turn and generate electricity. Others get their electricity from wind turbines. This works in a very similar manner, but instead of steam causing the turbines to spin, it is the wind that does the work.
Another growing technology that is constantly becoming more and more popular is solar energy. This works through harvesting the power of the sun to generate electricity. All of these various forms of creating electricity are commonplace in our world today. Cities, companies and even individual homes use these various ways to generate electricity. The real question now is, how can water be used in this process?
Hydroelectricity is an awesome way of creating electricity. It is literally taking the natural flow of water and using it to create electricity. This form, as well as wind turbines, are incredible because they simply take a natural process of nature and use it to develop electricity.
The theory of hydroelectricity is to build a dam on a large river that has a large drop in elevation. This dam will then store large amounts of water behind it in a reservoir. The dam wall has a small system toward the bottom called a water intake. The natural force of gravity will cause the water to be pushed through the water intake and flow down the penstock, or tunnel, within the dam walls.
At the end of the penstock there is a turbine propeller. This turbine propeller will begin to spin as the water flows past it. There is a shaft attached to turbine that connects to the generator above it. The friction created inside this generator is what produces the power. Power lines are connected to the generator that carry electricity to your home. After the water causes the turbine to spin it then continues through the tailrace into the river past the dam. It is as simple as that; the natural flow of water created electricity for all of us to use.
If you want to geek out even more on how this turbine works, here is an even more in depth description. Thanks to the U.S. Army Corps of Engineers, we have a good explaination of how the hydraulic turbine turns the water flow into electricity:
"A hydraulic turbine converts the energy of flowing water into mechanical energy. A hydroelectric generator converts this mechanical energy into electricity. The operation of a generator is based on the principles discovered by Faraday. He found that when a magnet is moved past a conductor, it causes electricity to flow. In a large generator, electromagnets are made by circulating direct current through loops of wire wound around stacks of magnetic steel laminations. These are called field poles, and are mounted on the perimeter of the rotor. The rotor is attached to the turbine shaft, and rotates at a fixed speed. When the rotor turns, it causes the field poles (the electromagnets) to move past the conductors mounted in the stator. This, in turn, causes electricity to flow and a voltage to develop at the generator output terminals."
Some places will use a system called pumped storage. Pumped storage is a method of keeping water in reserve for the higher times of demand. This system will take water that has already run through the turbines and pump it back up to create a storage pool above the powerplant. This is done during times of the day and night where power demand is lower. When power demand is higher the water is allowed to flow back through again to create more electricity.
Hydroelectricity in our cities
It has been shown that we are able to use the natural flow of water from rivers or storage pumps to create electricity; so couldn't we use this technology for the water flowing in our cities? This has been created and is being tested in various places throughout the country. One such place is Portland, Oregon.
Portland offered their city as a place to test out this new technology. Because of the large amounts of water constantly moving through municipal pipelines in most major cities; engineers have developed a pipe system that will generate electricity as the water is flowing through it. The water will be flowing in our pipelines either way so why not manipulate its flow to produce hydroelectric power, right?
Simply you replace a stretch of existing gravity-fed pipelines used for transporting water to and from houses, business, etc. The water will flow through these pipes and spin four 42-inch turbines, similar to the process happening on the dam. Each of these turbines have a generator on the outside of the pipe that will generate the power and feed it back to the city. Thus making the city self-reliant. The turbines inside of these pipes have very little effect on the flow rate of the water throughout the city. This concept truly is genius.
A 200-kW system can generate a decent amount of power for the city. These systems are expected to generate an average of 1,100 megawatt hours of energy per year. Of course this varies on the size of the cities and the intake of water. This average of 1,100 megawatt hours could potentially power up to 150 homes within the city and over the next 20 years create about $2million in energy sales.
These forms of city pipeline hydroelectric systems are still in the process of being tested. There was a system installed in 2012 in California that has been successfully producing and saving money. If results like this continue to show, there could be an increase in these types of systems throughout the country.
Mankind has and will continue to make more improvements such as those spoken of today. It truly is incredible how nature can be used and harnessed to create this ever essential power of electricity. Next time you see a beautiful river with a large drop you can say just as the fish did as he swam over it, “Dam it”. But this time with a hydroelectric dam.