Hydropower

Hydropower involves using the energy derived from the movement of water to power machinery to produce electricity. ¹ The amount of available energy in moving water is determined by its flow or fall. Hydropower is one of the oldest sources of energy and has been used for thousands of years. Water Wheels and mills were found in most of the early cultures. Water wheels were mostly used to grind grains in ancient India and water powered mills were also used to saw timber and stone in Imperial Rome. Today, hydropower is considered as renewable energy and is used to produce electricity. In the United States, hydroelectricity power accounts for 6 percent of the total electricity generation.

Technology basics

The basic concept is that moving water turns a turbine, which in turn spins a generator to produce electricity. In a typical hydro system, water drops from the upstream to create flows that drives turbine. Turbines are connected to electricity generator working as wind turbines. The more pressure creates more power.

Advantages

Hydropower has several environmental and social advantages compared to conventional energy.

Hydropower derives energy from the natural following water, which produces very few greenhouse gases and no other air contaminants.

Hydropower takes advantage of the water cycle to produce energy, thus it is reliable and renewable.

Some hydropower projects allow users to store water to generate electricity for a variety of use. For example, water stored reservoirs can support intermittent renewable sources, such as wind and solar power. It can also offer recreation opportunities, like fishing, swimming and boating.
Hydropower is a domestic source and can reduce reliance on foreign and potentially carbon-intensive energy sources.
Small hydropower projects also have low operating and maintenance cost.

Disadvantages

However, hydropower also presents possible negative impacts on the environment.

Hydropower plants can negatively influence water quality and flow. The construction of dams can also threaten the habitats on riverbank.
Hydropower plants can also impact fish population. Some fish species migrate to upstream to spawning grounds, while dams sometimes make it difficult for those species to migrate between upstream and downstream. Fish ladders are used to aid fish passage, however, some species extinct because of human behaviors, such as Chinese sturgeon.

Small-Scale Hydropower

Small-scale hydropower, also called microhydro, can power a household or a few households at a time. It uses the same kinds of turbines which are used in larger systems. However, unlike large dams, small-scale hydro projects do not require a dam, but only a barrier to impound or direct a sufficient and consistent amount of water into a pipe or channel to drive turbines and a generator. ²

Small-scale hydropower is a critical part of the Canadian hydropower industry. Small-scale hydroelectric facilities add about 100 to 150 MW to Canada’s power supply. More than 20 equipment manufacturers and about 70 engineering firms focus on small-scale hydropower project development. ³ In the developing world, small-scale and micro hydropower technologies are also helping bring electricity generation to remote areas.