Hydroelectric power
The maximum of the hydroelectric power that we use comes from the conversion of the potential energy of dammed water which in turn drives a water turbine, which in turn drives a generator. The energy extracted from water in this method depends on the height of the water and the volume and also on the difference of height in the source of water and its outflow height. This difference in height can also be called head, and is directly proportional to the potential energy, so to increase the potential energy; the water is sometimes passed though a pipe.
The formula for calculating the electricity production in a hydroelectric plant is
P=hrk,
where P is power in watts, h is height calculated in meters, r stands for flow rate in cubic meters per second, and k is a constant of 7,500 watts. This formula assumes an efficiency of 75%
Economics
The biggest advantage that hydroelectricity has is the cost elimination of the fuel. These hydroelectric plants are almost not affected at all with the cost of fuel and its escalation or depreciation. These plants also have a much longer lifetime and sustainability than the traditional fossil fuel fired electricity generation plants. The cost effectiveness further increases because they do not need manual labor, only supervisors are needed and that too few in number, most of the plants are automated and have been built 100 to 50 years back.
The dams are built for several purposes and the creation of hydroelectricity can have significant cost effectiveness if a plant s established along with a dam where the other activities have also been taken up. The dams cover their costs in 5 to 7 years of their making and then require little or no investment.
Greenhouse gas emissions
The biggest ecological advantage of having a dam is that there are no emission of carbon dioxide which is a greenhouse gas, causing furor among the conservationists about its effects in global warming and the consequences of life on earth. The carbon dioxide though is emitted while making the plant, it is a tiny insignificant fraction of the benefit it provides once it gets operational.
