A source of renewable energy
Hydropower technology uses falling water to create energy by driving turbines linked to generators. Gravity, in this case, is the energy source.
The heat from the sun evaporates water from the oceans and this water falls on the land as rain and runs back to the sea in rivers. Water on land has potential energy because it is higher than sea level. When water flows to a lower level, that potential energy changes to kinetic energy (energy of motion) which can rotate water turbines to produce electricity.
Electricity generated by the energy of falling water provides about 10 per cent of the electricity produced in New South Wales each year.
Many new hydro sources are now developed using existing water storage systems - e.g. using the natural fall from town systems like Chichester, and from irrigation canals like Berrigan.
- The principle of electricity generation is essentially the same in both hydro and thermal (steam) power stations. However, where high-pressure steam produced in coal-fired boilers drives horizontal turbines in a thermal station, water drives vertical turbines in a hydro station.
- Hydro-electric power generation uses the energy created by falling water to produce electricity. Water stored behind a dam is released through huge pipes called penstocks into a power station located below the dam wall.
- The water is directed through the base of a vertical turbo-generator where it passes through the turbine blades, which are attached to the shaft and generator. The shaft spins at a controlled speed and the energy output is regulated.
- At the top of the unit is a generator comprised of a spinning, magnetised rotor that is attached to the shaft and contained within a stationery coil called a stator.
The generator produces alternating current (AC) which, after being increased in voltage via a transformer, is passed through a switchyard into the electricity grid.