As part of assessing the best energy sources for the future, we are looking at the pros and cons of these different energy sources.
This is our guide on the Pros & Cons Of Hydroelectric Energy.
Summary – Hydroelectric Energy Pros & Cons
- Renewable, unlike fossil fuels which are finite
- Green energy – zero emissions while in operation
- Reliable – there’s little inconsistency and fluctuation in water energy compared to sun or wind energy
- Flexible and adjustable when in use
- No fuel required (like coal or nuclear for example)
- Running costs are usually pretty low
- Hydropower built with dams provide multiple benefits
- Can be made on both small and large scales
- Can be a portable source of energy on a small scale
- Can give individuals energy independence
- Can supply energy off grid
- Can be used rurally or remotely where there are running water sources
- Damming of water can be environmentally damaging
- Large scale hydroelectric plants can be very costly to construct
- Limited in terms of growth for large scale hydroelectric power – there’s only a limited number of places in the world that are suitable
- Sensitive to natural events
Hydropower is already well developed. It can be used on large scales like dams and major water diversion projects, or on smaller scales in rivers and streams with water wheels and portable water turbine energy generators. Although it still has long term use because it is renewable and green energy, it has limited growth potential because of the limited water reservoirs to install major hydropower plants (some places like the Grand Inga Dam in Africa have huge potential, but face feasibility challenges like being overpriced, funding issues, planning issues and corruption). It’s most likely to be a supplementary power source, and a power source for small communities, and isolated or rural areas near streams and rivers.
*Note – the above pros and cons are broad generalisations. Obviously there are different variables to each specific energy project that impact the final pros and cons (like new technology that reduces emissions for coal power plants just as one of many examples). Each energy project and situation (in different countries and cities) should be analysed individually. Having said that, some broad principles and patterns about the pros and cons of different energy sources tend to stay consistent too.
What Is Hydroelectricity?
Producing electricity from hydropower, specifically hydroelectric power plants built on suitable reservoirs.
In 2015 hydropower generated 16.6% of the world’s total electricity and 70% of all renewable electricity.
However, there is also small scale hydro power systems that use water wheels to generate energy. Small and micro scale hydros are good in remote areas.
– wikipedia.org, and efficientgreenpower.com
Hydroelectric Energy Pros
- Renewable – unlike fossil fuels, hydroelectricity is renewable because water of the natural water cycle.
- Green Energy – hydro electricity does not produce greenhouse gases or pollution, except for the manufacture and installation process. But, while in operation, it is clean.
- Reliable – there’s very little fluctuation in terms of the output of hydro electric power plants. All they need is water and they can generate energy as a base load energy source running continuously. This is unlike wind power for example which can be intermittent.
- Flexible & Adjustable When In Use – adjusting water flow and output of electricity is easy. At times where power consumption is low, water flow is reduced and the magazine levels are being conserved for times when the power consumption is high.
- No Fuel Required – unlike a coal power plant which needs to be refuelled with coal, water power plants don’t need to be fuelled. They have access to continuos water flow.
- Running Costs Are Usually Quite Low – plants do not require a lot of workers and maintenance costs are usually low.
- Dams Provide Dual Benefits – for hydropower plants built on dams, the dams provide flood control and irrigation techniques, in addition to hydropower.
- Micro & Small Hydropower Is Available – can be installed in small rivers or streams with little or no discernible environmental effect or disruption to fish migration. These are 10 megawatts, or projects of 30 megawatts in North America. A small hydro plant may be connected to a network or may only provide energy to an isolated community or a single house.
– energyinformative.org, and efficientgreenpower.com
Hydroelectric Energy Cons
- Can Be Environmentally Damaging – damming of water, changed water flow and the construction of roads and power lines can all affect water environments and wildlife, such as fish. Dams or major water diversions with manipulation of water around the generator can negatively impact ecosystems for fish species who rely on certain water levels and other water environment characteristics.
- Very Costly To Construct – hydroelectric power plants can be expensive to construct and install.
- Is Limited Physically In Terms Of Growth – there’s only a limited number of suitable reservoirs where hydroelectric power plants can be built and even less places where such projects are profitable. As of 2014, there are currently about 30 major power plants that are expected to generate more than 2.000 MW under construction. Only one of these projects was started between 2012 and 2014.
- Sensitive To Natural Events – Electricity generation and energy prices are directly related to how much water is available. A drought could potentially affect this.
Example Of Hydroelectric Energy Being Used In China
- Hydroelectric power has become China’s main source of renewable energy production.
- The controversial Three Gorges Dam, completed in 2012 at a cost of over $37 billion, is the largest hydroelectric dam in the world and boasts a generation capacity of 22,500 MW.
- The dam generates 60 percent more electricity than the second-largest hydropower dam, the Itaipu dam in Brazil and Paraguay.
- Including the Three Gorges Dam, China has constructed 4 of the top 10 largest energy-producing hydroelectric dams in the world.
- From 2000 to 2015, China increased its hydroelectric energy-generation capacity by an impressive 408 percent. As a result of the Three Gorges Dam and other projects, China became the world leader in hydropower in 2014.