Hydro

Interesting Facts

• Large hydro-power projects capture water behind a dam and release it progressively to create a continuous stream of water from which the kinetic energy is captured. (Kinetic energy is the energy possessed by an object or fluid by virtue of its motion.)
• Hydro-power produces one fifth to one sixth of all the world’s electricity.
• Hydro-power makes up over 90% of electrical output from renewable sources.
• Scotland generates around 11% of its electricity from hydro sources!
• Canada, the USA and China are the three largest generators of hydro electricity.
• Brazil is also one of the world’s leading producers of hydroelectric power, with a current capacity of about 58,000 megawatts and hydroelectric providing 92% of the nation’s electricity.
• Worldwide there are literally hundreds of thousands of micro-hydropower sites (up to 100 kW) that could be developed to supply environmentally friendly renewable energy.

Benefits

• Once the dam is built, the energy is virtually free.
• Little waste or pollution is produced.
• Much more reliable than wind, solar or wave power as the water flow can be controlled.
• Additional water can be stored behind a dam for use during peak times. The concept is known as pump-storage, where surplus electricity is used to pump water back uphill for release later.
• It is very efficient, with large scale hydroelectric plants reaching energy conversion levels of 90%.

Downsides

• Dams are very expensive to build.
• Building a large dam will flood a very large area upstream, causing problems for animals that used to live there.
• Finding a suitable site can be difficult – the impact on residents and the environment may be unacceptable.
• Hydroelectric power sites are often remote which leads to higher distribution costs.

Local Applications

• Small scale projects for homes and businesses.
• Small hydro installations on River Don being refurbished.