Putting gravity to work

The source of Energy

The formula

Connecticut as example

Niagara Falls produces about 2000 MW of electricity. Why don't we use more hydropower in Connecticut, for example? 

Water behind a dam has energy by virtue of being at high elevation. One kilogram has 9.8 joules of energy for every meter of elevation it has. A hydroelectric power plant uses that energy to turn a turbine, thereby to generate electricity. The power available depends upon how high the dam is, and how much water flows. The power available from a hydroelectric plant operating at about 85% efficiency can be calculated from 

P (watts) = 8300 ´ dam height (meters) ´ flow rate (cubic meters per second)

The average year in Connecticut brings us about 1.1 meters of precipitation. The land area of Connecticut is 5000 square miles, which is  square meters. The total volume of water falling on Connecticut in one year is about  million cubic meters. This amounts to 450 cubic meters per second. If we could use all of the water falling on the state, and we had a 200-foot dam (61 meters) to hold the water, we could get about 230 MW out of it, which is less than 10% of the Connecticut demand for electrical power. The Mayors of New Haven, Bridgeport, and most other major Connecticut cities might object to having their cities under water. So might environmentalists. 

 The Solar Fraud discusses hydropower. 
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