Load shedding is a major concern right now in South Africa and I am sure that many other countries in Africa, like Nigeria and Ghana experience the same, so will know what we are currently going through. There is a lot of talk around alternative solutions to power generation and it got me into a discussion with fellow colleagues, about Hydropower.
It seems that there is a growing need in Africa to look at other sources of power and Hydropower (also known as water power) is one of the major growing concerns in the Energy sector in Africa.
Hydropower is power derived from the energy of falling / running water and running water, which can actually be harnessed for purposes of irrigation; operating gristmills, sawmills, textile mills, dock cranes, domestic lifts and the likes.
Hydropower is commonly used in conjunction with the modern development of hydroelectric power, which allowed use of distant energy sources. Another method used to transmit energy is by using a trompe, which produces compressed air from falling water. Compressed air could then be piped to power other machinery at a distance from the waterfall. Hydro power is a renewable energy source.
Hydropower is the renewable energy contained in flowing water. Electricity generated using hydropower is known as hydroelectricity and is generally considered to be reliable.
How Hydropower works
Water’s power is manifested in hydrology, by the forces of water on the riverbed and banks of a river. When a river is in flood, it is at its most powerful, and moves the greatest amount of sediment. This higher force results in the removal of sediment and other material from the riverbed and banks of the river, locally causing erosion, transport and, with lower flow, sedimentation downstream.
Hydropower: How electricity is generated
A hydroelectric power station converts the kinetic, or movement, energy in flowing or falling water into electrical energy that can be used in homes and businesses. Hydroelectric power can be generated on a small scale with a ‘run-of-river’ installation, which uses naturally flowing river water to turn one or more turbines, or on a large scale with a hydroelectric dam.
Hydropower: Hydro-electric Dams
A hydroelectric dam straddles a river, blocking the water’s progress downstream. Water collects on the upstream side of the dam, forming an artificial lake (also known as a reservoir). Damming the river converts the water’s kinetic energy into potential energy: the reservoir becomes a sort of battery, storing energy that can be released a little at a time. As well as being a source of energy, some reservoirs are used as boating lakes or drinking water supplies.
Hydropower: How energy is converted
The reservoir’s potential energy is converted back into kinetic energy by opening underwater gates (also known as intakes) in the dam.
When an intake opens, the weight of the reservoir forces water through a channel (penstock) towards a turbine, forcing the water to rush past the turbine and hit its blades, causing it to spin. This process converts some of the water’s kinetic energy into mechanical energy. The water then finally flows out of the dam and continues its journey downstream.
Hydropower: Turbines and Generators
A shaft connects the turbine to a generator and once the turbine spins, so does the generator. The generator uses an electromagnetic field to convert this mechanical energy into electrical energy.
As long as there is plenty of water in the reservoir, a hydroelectric dam can respond quickly to changes in demand for electricity. Opening and closing the intakes directly controls the amount of water flowing through the penstock, which determines the amount of electricity the dam is generating.
Hydropower: The location of the turbine
The turbine and generator are located in the dam’s power house, which also houses a transformer. The transformer converts the electrical energy from the generator to a high voltage. The national grid uses high voltages to transmit electricity efficiently through the power lines to the homes and businesses. This is where other transformers reduce the voltage back down to a usable level.
Useful facts about Hydropower:
- Hydropower is renewable energy source that doesn’t cause global warming because it doesn’t releases dangerous greenhouse gases.
- China is the largest producer of hydroelectricity, followed by Canada, Brazil, and the United States (Source: Energy Information Administration).
- Hydropower is the most important and widely-used renewable source of energy.
If you would like to read more about this topic on one of the most engaging topics being discussed at the moment, then see these very interesting articles, from which this article was based:
Thank you for reading!
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