Simply put, it is a form of renewable energy generated from water stored in dams or from flowing rivers to create electricity in hydropower plants. Like other forms of electricity generation, it uses a turbine to convert the energy of the flowing or falling water to turn the blades which, in turn, converts this mechanical energy into electrical energy. Hydropower now equates to over 70% of all renewable energy generated across the world (albeit with a very heavy percentage of that coming out of China) and approaching 20% (1/5th) of the world’s total electricity production (according to the same source) – it is big business.
Hydropower is, of course, dependent on rainfall but despite this is still arguably the most flexible and consistent of the renewable energy sources.
There are three main types of power station:
Run of river – where the electricity is generated through the flow of the river
Reservoir – where power is generated through the release of stored water
Pumped storage – where stored water is recycled by pumping it back up to a higher reservoir to be released again.
In this way hydropower can meet both base load demand as well as peak and unexpected demands and accounts for a considerable percentage of installed power capacity in many regions of the world. Hydropower is not new - many plants have been operational for over fifty years.