Hydropower is a renewable source of generated electricity, the production of electrical power is based on gravitational force of water flowing or falling on the ground. In easy terms it is also known as water power and is used from ancient times to operate different devices in watermills, textile mills and domestic lifts etc. Industrial revolution in late 19th century was one major reason of using power of water for different purposes. Hushing was introduced in that period, which later evolved into hydraulic mining.
Hydraulic power-pipe network gave boost to this field as pipes were used to carry water with extreme pressure. In this design air bubbles were purposely mixed with water to allow it to fall down a shaft and then flow back to surface at slightly lower level. Principles used in this design were followed later as well.
How hydropower works?
Today more than 24% of world’s electricity is generated through hydropower, which is total of 675,000 megawatts. It is the force of water which has enabled us to generate electricity in such huge amount. To generate electricity hydropower plants are installed around the world which follows very simple concept of working. Following are components of conventional hydropower plant
Dam: most plants rely on dams to hold water and create reservoir of it. A dam is also used as recreational lake sometime.
Intake: to store water in a dam gates are used on it, to open dam and let it flow down towards the ground. A pipeline is used near the gates to carry water to turbine and build pressure as water flows through the pipe.
Turbine: after passing through the pipes, water strikes to large blades of turbine and turn them. These blades use to attach to generator which generates electricity. Most common type of turbine used for hydropower plants is Francis Turbine that holds curved blades.
Generators: as blades of turbine start moving, the magnets inside the generator also do so. These giant size magnets rotate copper coils and produce alternating current which is converted into higher voltage current with help of transformer.
Power Lines: power from generator comes out through some wires which are known as power lines. Combination of four wires, work together to carry electricity towards main grid.
Outflow: it is important to carry used water towards river downstream. A structure of pipelines is used for this purpose.
Types of hydropower:
The basic purpose of using hydropower is to generate electricity from a renewable source in cost effective manner. Today different methods are used to generate hydroelectricity named as
Conventional hydroelectricity: this is basic method of generating electricity and use dam for this purpose.
Run of the river hydroelectricity: in this type kinetic energy is captured from rivers or streams and is used to generate electricity. Dams are not part of this type.
Small hydro: these are projects to generate 10 megawatt or less of electricity. In these projects artificial reservoirs are not used.
Micro Hydro: it provide with few kilowatts of electricity to isolated homes and small industries.
Pumped-storage hydroelectricity: here water is pumped to store in time of its low demand and is released to generate electricity when its demand is high.
Advantages and disadvantages of using hydropower:
Different advantages are associated with hydropower as compared to other renewable sources of energy, like
- As this power comes from water is clean source of energy and does not add pollutants to air like burned fossil fuels and natural gas.
- For every country this is a domestic source of energy
- Flow of water can be controlled, therefore it is always available at time of need
- Once dam is constructed and we can get energy at constant rate
- Used water can be used to irrigate fields.
- These are some disadvantages associated with hydropower
- With construction of dam wildlife and fishes get affected
- Large Dam Construction has been linked to increased propensity of Earthquakes
- Hydropower plants cannot be build anywhere
- Construction period and cost of hydropower plant is high