Economic potential-water energy

Natural circle

•  Each river or sea stream has the kinetic energy from the movement of water. That RES has a huge energy potential that is utilized through water head WPP, HKP and wave power plants.

How much electricity can a hydro energy installation produce?

•  That depends on the rise and the fall of water that is passing through a WPP. When the fall is bigger, water contains more energy. Dependence between debit and energy is also directly proportional.

•  The amount of energy that the water contains can be evaluated with the following formula:

E = g x H = V x ? x g x H


E = Potential energy

M = Mass of water that has passed through the section of the river

g = Acceleration of gravity ( (9 . 81 m / s 2 )

H = Displacement

V = Debit of water

P = Thickness of water

•  To determine the average annual debit of water, it is necessary to make accurate measurements of the water flow for as long period of time as possible.

•  Use the national and regional statistic data for the amount of rain.

Energy potential of wave power plants

•  Moving water has a kinetic energy. Energy that is passing through the turbine with an area of 0 ( 2 ) of water with thickness p and speed of water V( /) can be calculated with the following formula:

= 0,5.?. 0 .V 3

•  Energy that can be transformed into mechanic is limited for a turbine in open water up to:

= 0,5. .?. 0 .V 3


Cp is a coefficient of efficiency, as its value is limited up to a theoretical maximum of approximately 0,593.

Waves are not a constant source of energy. The table shows the potential for 24 hours.




Incorporating a technology for utilization of water energy in a company has the following advantages:


•  Water energy is a constantly available RES.

The rotation of water in nature and interaction between the Moon and the Earth provide constant movement of water masses. So that technologies such as HKP wave and tide power plants can be used through out the year.


•  Low operation costs

For hydroelectric energy generation fuels are not required, and the maintenance costs are minimal.


•  Reliability of the technologies

Hydro energy technologies such as water head WPP and HKP have a long life, unlike the tide and wave power plants. There are existing WPP that have been operating for more than 50 years, which is an indicator of their reliability.


•  Flexibility of the technologies

Pump-accumulator WPP are used to compensate the differences in use in the different hours of day and night. During nighttime when there is less consumption in the grid, electricity from conventional sources is used for moving the water back into a water basin, and during the peak hours 8-12h and 13-21h it is let back through the turbine and generates electricity. They are the only economically effective accumulator for great amounts of electric energy.

•  Hydro energetic installations have 50-55% CUA that makes them the most effective technology for production of electric energy from RES.



•  Mobility of the technologies.

HK electro generators are small in size and do not require dam walls and that makes it easy for them to be transported to remote and isolated regions.