History And Importance Of Hydropower

Hydropower is produced by converting the kinetic energy of the moving water to electrical one. The motion of water is part of a continuous natural phenomena called the water cycle. Energy from the sun evaporates water from oceans and rivers and raise it as steam or vapor. When the watervapor reaches a colder atmosphere level, it condenses and forms cloud. The moisture eventually reaches a point at which air cannot keep carrying it, so it falls to the earth as rain or snow, this process is called precipitation. Gravity drives the water, moving it from higher ground level to lower one. The force of moving water can be extremely powerful. Hydropower is a renewable energy source because the water on the earth is in a continuous motion. As long as the water cycle continues, we will not run out of this source.

In the old past people used a simple machine called water wheel to produce a specific motion using the movement of the water in the rivers or any other source. The water wheel is located below a source of flowing water. It captures the water in plates that is normal to the wheel, the water hits the plates causes the wheel to turn. Water wheels convert the kinetic energy of the water into another type of motion. That energy can then be used to grind grain, drive sawmills, or pump water. There are several examples of water wheel application in the past. For instance, the Greeks used water wheels to grind wheat into flour more than 2,000 years ago. In the beginning of the 18th century, factories at America and Europe used it also to power machines.

In the late 19th century, the potential energy of water was used to generate electricity. The first hydro electric power plant was built at Niagara Falls in 1879 and it started a revolution of Hydro electrical power plants. in the following decades, many plants were built.

At the peak in the early 1940s, hydropower occupies 33 percent of USA electricity. But, by the end of 1940s, inexpensive fossil fuel plants also joined the competition. At that time, plants burning coal or oil could make cheaper electrical power than hydro power plants. This fossil fuel plants was burning the fossil fuel and the hydro power plants till the 1970s. In that decade the way was opened for hydro power plants again because of the oil shocks that made people showed an interest in renewable power sources.

1.3 Importance

In this part of the report, I am going to relate people and hydropower in a logical chain, that will show how much it is important to change the way that electricity is produced nowadays.

People, as we all know, are part of the natural world and the materials they are using in building, clothing, food, etc come from natural resources. What surround us are composed of large numbers of built environment, the facilities built by humans for comfort, security, and well-being. As our built environment grows, we become more reliant on what it is offering to us. To satisfy our demands improvement to our built environment is needed, to do such upgrading we need electricity which can be generated by using the resources of natural fuels. In obtaining these resources, it is necessary to drill oil wells, tap natural gas supplies, or mine coal and uranium. In order to put water to work on a large scale, storage dams are needed.

Some human activities have more lasting impacts than others. Techniques to mine resources from below the earth may leave long-lasting impacts on the environment. Oil wells may detract from the beauty of open landscapes. Reservoirs behind dams may cover whole valleys. The usage of energy sources can further impact the land, water, and air in different amounts. People want clean air and water and a pleasing environment. They also want power to heat and light the homes and to run machines. So, what would be the solution? Logically there are two straight forward solutions, but both are hard to be done. One solution is curbing The increasing demand for electrical power. As explained above, this is something that far from the actual trend. The other solution is that more power must be produced in environmentally friendly ways.

Conservation can save electricity, but our population is growing. In other words even if we are very conservative in power consumption, our demand is still increasing. So, growth is inevitable. So again, the wisest solution is a careful, planned approach to how to bring a new, efficient ,clean and renewable resource of energy. All choices must be examined, and the most efficient, acceptable methods should be adopted. One alternative is hydro power plants and based on the characteristics of this plants it seems to be a successful choice. These features are many, one is that hydro power plants do not use nonrenewable resources to make electricity. They also do not produce pollution, rarely fail, have low operating costs and they are reliable.

WAYS OF HYDROPOWER PRODUCTION

I will discuss in this part of the report two methods to produce power using hydro energy that fit with the conditions in Saudi Arabia which are the lack of dams and rivers. These two ways are the sea power plants and power production in water Desalination stations.

Using Sea Energy

First of all I will discuss tidal energy as one type of the sea energy. The tides rise and fall eternally . Tides are changes in the level of the oceans caused by the rotation of earth and the gravitational force from both the moon and the sun. Nearshore sea level can vary up to 15 meters, depending on different factors. Tidal energy is the most promising source of ocean energy for today and the near future.

Tidal energy plants capture the energy in the same manner that happened in dams, but here the dam is the whole coastal line. The water is filling this virtual dam and draining it twice a day. Then, by sitting up a set of turbines that connected to gears to convert the motion of the water into electrical power, and by building specific structures under the sea level which magnify the speed of water during the filling and draining process we will have a perfect tidal power plant. The oldest and largest tidal plant, La Rance in France, has been successfully producing electricity since 1968.

Nowadays, the electricity from tidal plants costs a lot compared to other ways. It is expensive and takes time to build up the turbines and the structures, which can be several miles long. On the other hand, the fuel free, always available and green, and the plants are easy to maintain. For example, two operators are needed to run the La Rance plant at night and on weekends. And the plants is durable with little maintenance.

Other type of sea energy is current and marine stems. The water in seas are continuously moving. We can use some of the ocean’s energy, but most of it is out of reach. Capturing this energy problem is not a problem, the real problem is transporting it to the land. Generating electricity in the middle of the ocean just doesn’t make sense since there is no one living in the middle of the sea. We can only use the energy near shore.

Using Steam Energy (In W.D.S.)

Of course, during the process of desalinating water, steam must be produced. And the moving pressurized steam has tremendous energy in it. Energy in steam is held both in heat and pressure. When heat is applied to a water, the electrons begin to move quickly around

molecules. The change of a liquid state to a gas state takes place when the moving molecules take to the air because of its rapidly moving electrons. The water molecules up in the air stay away from each other. When very large number of water molecules are heated, and all repelling each other, pressure builds. When this pressure is released, energy can be generated. When the pressure in steam is released, it transfers its energy to whatever it hits, so by putting a turbine or a piston, this steam energy will be converted to mechanical one. This movement can be used to generate electrical energy, or it can use the steam energy directly in steam machines, like steams trains.

COMPARISON BETWEEN HYDRO ENERGY AND OTHER RESOURCES

In this section I will come over many aspects about hydro energy like the cost of power generation depending on hydro energy. Then, I am going to mention some up and down sides of this energy source.

Cost

Hydropower on average is the world cheapest way to generate electricity today. No other energy source, renewable or not, can be compared to it. Today, it costs about a cent per kWh (kilowatt-hour) to produce electricity at a typical hydro plant. Comparing to others, it costs coal plants about 4 cents per kWh and nuclear plants about 2 to generate electricity. Producing electricity from hydropower is cheap because of many reasons. For instance, if a dam has been built and generators installed, the energy source becomes free one. They are cheap also due to their firm structures and simple equipment. Hydro plants are reliable and durable, and their maintenance costs are low compared to coal or nuclear plants.

3.2 Advantage

The advantages of hydroelectric power are so many. The power created through the use of dams and turbines is not reliant on coal, oil, uranium, or any polluting nonrenewable resources. Unlike other sources of power, it does not create carbon monoxide smoke, nuclear waste or any other harmful materials. The second advantage is when you construct a dam, it can create power for years and years to come. For example, the Hoover Dam in the US was constructed back in 1936 and it still provides a large amount of power to California, Nevada, and Arizona, three of the most power consuming states. Another advantage is aside from initial construction costs, it is simple and cheap to maintain a turbine. The Hoover Dam again has had only one large renovation done in the 90 years ago since it was created. The last up side I want to mention, is about water, the source of the turbine’s power, is one of the earth’s most abundant resources and it is completely renewable. The tides, dams, streams and lakes that hydro electric power sources use to generate power are always moving about, and the turbine simply captures the power, converts it and sends it out to the needed areas.

Disadvantage

While I spend the majority of report explaining the advantages of hydroelectricity, there are a few disadvantages in terms of cost and wildlife damage.

The major disadvantage of hydroelectric power, is its initial cost. Building a dam or marine structures is costless thing to do. Another disadvantage is the need of hiring a professional person who can locate where the dam should be built, as well as a place where the water can build up. In addition to that, redirecting the river for a few months while constructing the dam or evacuating a shore and keeping it dry until building the enormous nuzzles, which is a huge project, and will cost billions. Now, to put things in perspective, once a dam is built, all what is basically needed is a few maintenance workers, so costs become low. Secondly, there is a fact that building a hydroelectric power source is terminating the local wildlife. Whatever done, destroying the surrounding landscapes specially for the dam well happen, whether because of building a whole new lake, or because of adding a large wall into an area where fish used to swim freely back and forth hydroelectric power certainly takes a toll on the natural habitat. Fortunately engineers started to become a little more conscious of the damage, by building smaller dams, or by providing overflow areas so that fish do not stuck being. While these changes are floating to the surface slowly, at least they are being made. Finally, there is the element of social change that can happen because of a dam being built. By their nature, all sources of hydropower must limit the flow of water in order to make them build up pressure to attain maximum results. As the water is limited, towns and villages downstream can sometimes have their water source drained down to a trickle, particularly after multiple dams, waterwheels and simple use of water can dry riverbeds and render some towns without a water source.

Overall, though, considering how much potential energy can be gained by hydroelectric power, the disadvantages of hydroelectric power are probably worth enduring, since they produce so little carbon dioxide, and provide an endless source of electrical power to the area.

CONCLUSION

In this report, I discussed in detail the Hydro power production trend from the past till now. I gave a brief definition of hydro energy and talked about it importance. In the second part, I explained the types of hydro energy that is available in KSA to use. These types are tidal and marine streams energy and moving pressurized steam in water desalination plants. I introduced the way of each process, and its main up and down sides of them. And finally, I compared Hydro energy with other resources of energy in terms of cost, environmental impact, simplicity and durability. I found out that it is in fact the cheapest way to produce electricity, also it has a simple and firm structure that can last for years with a little care.