Hydroelectric energy refers to the electricity obtained naturally from water without producing gases that harm the environment and without altering the water source itself.

A hydroelectric plant produces clean, renewable energy that can be used as such or sold to local electric utility companies.

How a hydroelectric power station works

Falling water activates a water turbine that transforms kinetic energy together with potential energy into mechanical energy. The water turbine is connected to a generator which produces electricity. The amount depends on the head, the difference in height between the outflow of the water and its source, as well as the volume of the water outflow at any given time (m3/s).

The type of turbine is chosen according to the characteristics and power capacity of the site. Those most commonly used are:

The Peltron or cross flow turbine - used in small plants because it is well-suited to exploiting the potential of more limited volumes of water outflow. It can have a horizontal or vertical axis in order to adapt to different water conditions and logistic requirements. Its blades are spoon-shaped producing a maximum of six jets.

Francis - a reaction turbine, useful for average-sized plants with a power capacity of around 100KW. The main feature of this turbine is that it exploits the water head to the full from where the water falls to where the water drains out.

Kaplan - suited to irrigation systems with small to medium volumes of outflow and water heads starting at two meters high. The machine consists of a rotor with adjustable blades that automatically change their speed according to a speed regulator while allowing the system to maintain maximum efficiency.

A hydroelectric power station consists of:

  • A dam, or water blocking element
  • A channel or pipe connection
  • A source pool
  • A penstock
  • An electrical facility: a turbine, a generator, interface and control panel
  • A means of replacing the water


Renexia has initiated research to develop new ways of exploiting the current from rivers.

The company is currently involved in a financing project to repair 13 dikes on the river Arno, which will allow electricity to be produced via 12 mini hydroelectric power stations. The total power capacity is over 10.5 MW and the project includes the installation of 36 turbines of various types with different rated outputs, water heads and volumes of water outflow.




> Solar
> Photovoltaics
> Thermodynamics
> Wind power
> Hydroelectric power
> Geothermal power
> Biomass



Copyright © 2012 Renexia SpA. (P.I. 02192110696). All rights reserved.