Hydroelectricity advantages and disadvantages include flexibility, cleanliness, low cost, efficiency, scalability, renewable and domestic production, conservative process, multipurpose application and geographic versatility (advantages); flood risk, ecosystem disruption, high capital cost, climate and water dependence, land use problems, and potential failure(disadvantages).
This article discusses hydroelectricity pros and cons, as follows;
-Pros / Advantages of Hydroelectricity
1). Flexibility as one of the Advantages of Hydroelectricity
Hydroelectricity is a flexible form of power.
There are various reasons behind this. One of them is the fact that hydroelectric systems can be designed to suit the environmental, industrial and economic conditions of any region in terms of the amount of power and specific mechanism of electricity generation. This attribute may also be described as adaptability.
Also, hydroelectricity can be generated with seamless integration of other renewable and non-renewable energy technologies.
What this means is that hydropower plants can function in collaboration with other energy systems like coal-fired power plants, wind turbines and solar energy systems . Because of its relative stability and consistency, hydroelectricity can be used as a supportive form of power supply for these technologies.
2). Hydroelectricity is Relatively Clean
This is another example of the advantages of hydroelectricity. The process of generating and consuming this form of power is considered to be ‘clean’, relative to most alternatives.
Basically, the assessment of cleanliness for any energy technology is based on its effects on the environment. With regards to scale of operation, hydroelectricity generation does not cause significant or severe levels of environmental degradation compared to other energy technologies.
In hydropower plants, there is no need for extensive fuel combustion as is the case for power plants that are driven by nuclear fuel, renewable biofuel and non-renewable fossil fuels. Therefore, the risk of toxic or environmentally-harmful gaseous byproducts is low.
As a clean form of power; hydroelectricity usage reduces the threat of global warming and climate change, in contrast to the use of fossil fuel power. Waste production in the process of generating hydroelectricity is also minimal, meaning that there is less need for simultaneous environmental remediation.
In addition to being relatively-clean, the generation of hydroelectricity also poses less safety hazard risk to professionals operating the power plant, and the general public. There is an overall-less threat to health, safety and wellbeing when hydroelectricity is used.
3). Low Production Cost as one of the Advantages of Hydroelectricity
Low cost of production is an advantage of hydroelectricity.
While it is relatively expensive to build a hydropower plant , the long-term cost of generating hydroelectricity using such plants, is low compared to alternatives.
The main reason for this is the fact that hydroelectric power plants demand less maintenance and operational expenses than most of their counterparts.
Because hydroelectricity is derived from water using a relatively-simple mechanism, there are fewer complexities in terms of components and functions, while generating this form of electric power. Less complexity implies lower risk of operational faults, and less need for intensive maintenance.
Hydroelectricity depends mainly on a hydraulic fluid like water, which is available in abundance in many parts of the world.
Unlike fuel-driven energy technologies, the primary energy source in hydroelectricity generation is inexpensive and less difficult to obtain. Also, cost is saved due to the clean and emission-free nature of hydroelectricity, as there is less need for environmental monitoring and remediation programs.
4). Efficiency as one of the Advantages of Hydroelectricity
Hydroelectricity is energy-efficient because there is minimal loss of useful energy in the power generation process in hydropower plants.
Whereas other energy technologies like solar, fossil fuel, geothermal and wind may range from 10 to 50 percent in efficiency, hydropower technology is capable of achieving energy efficiency of up to 90 percent .
In terms of transmission, the scale and versatility of hydropower plants, as well as the effectiveness of recent power transmission technologies, minimize transmission losses of hydroelectricity.
Additionally, hydroelectricity is relatively reliable. This is because water can be accessed and obtained in large volumes at all times of the year. Hydropower plants are also usually durable and less-susceptible to operational damage.
The reliability of hydroelectricity places it at an advantage with respect to other forms of electric power like wind and solar, which are highly-dependent on seasonal and climatic conditions.
5). Hydroelectricity Facilitates Economic Growth
There are various ways by which hydroelectricity contributes to economic growth.
One of these is through the renewable nature of hydroenergy. Because water is a renewable and clean resource, hydroelectricity generation itself is a relatively inexpensive process.
Also, when evaluated within the context of lifespan and power output, it can be argued that the cost of constructing hydropower plants is relatively low.
Depending on factors like size, complexity and geographic location, hydropower plants may range from $2 to $4 million per megawatt (MW) . This is not very expensive, considering that hydropower plants can produce thousands of megawatts in electricity for a prolonged period of time, with minimal maintenance.
Because of their multipurpose application, hydropower plants can serve other purposes such as recreation and tourism, which are of economic relevance.
Unlike fuel-dependent power, hydroelectricity is less prone to price fluctuations and economic inflation. Also, the hydropower sector improves the economy by creating jobs.
Lastly, hydroelectricity generation facilitates sustainable development, which is essential for overall economic growth of the society. Regions surrounding hydropower facilities usually benefit economically due to an increase in the rate of regional development and commerce.
6). Scalability as one of the Advantages of Hydroelectricity
Hydroelectricity is a scalable form of electric power, because it can be adjusted to meet specific needs and requirements .
The most common ways by which hydroelectricity supply is scaled, are by adjusting the volume and flow-velocity of the hydraulic fluid (water) in the hydropower plant respectively.
Because hydroelectricity is relatively consistent, it can be adjusted using the above methods repeatedly.
Also, hydroelectric systems can be expanded to cater for growing energy needs. This is possible due to the relative simplicity of hydroelectricity generation, and hydropower plants themselves.
7). Hydroelectricity is Renewable
One of the most common and significant advantages of hydroelectricity is the fact that it is renewable.
Because water is recycled and abundant in nature, the generation of hydroelectricity is a renewable process . For the same reason, hydroelectricity generation does not place any significant strain on the essential resources of the ecosystem.
The renewable nature of hydroelectricity places it among other important forms of renewable power, such as solar and wind, which are essential factors in the efforts to conserve environmental resources.
8). Hydroelectric Systems may Serve Various Purposes
Power plants used in the generation of hydroelectricity, usually serve multiple purposes.
Aside electricity generation, these systems can be used for agricultural purposes like irrigation . The situation of many hydropower plants in rural and remote areas makes this application effective.
The reservoirs and water falls which are components of hydropower plants may also be used for recreational purposes .
9). Domestic Production as one of the Advantages of Hydroelectricity
Another advantage of hydroelectricity is that it can be generated domestically .
The essential resource required for hydroelectricity generation; water, can be sourced locally in many regions of the world. This means that, unlike other energy technologies which depend on fuels, hydroelectric technology can be generated in many regions without the need for external exploration.
Domestic production of hydroelectricity implies that jobs can be created locally, and that hydropower plants can be independently operated within regional boundaries.
10). Hydroelectricity-Generation is a Conservative Process
The process by which hydroelectricity is generated in a power plant, is a conservative one, in terms of how resources are used and recycled.
Energy conservation and resource conservation in hydropower plants, is similar to other advantages of hydroelectricity like energy efficiency and renewable production.
Hydropower plants operate like an energy management system with regards to the use of resources. The sustainable nature of these systems implies that there is minimal energy loss as power is being generated.
Hydroelectricity generation does not affect the natural equilibrium of the energy pyramid and ecosystem, since it does not involve the burning of fuel or any net loss of resources and energy.
11). Geographic Versatility
One of the most beneficial attributes of hydroelectricity is the possibility of its generation across a broad range of geographic locations and conditions.
Basically, hydropower projects can be conducted in any region with significant amount of water resources. Technological improvements also increase the prospect of hydroelectricity generation in regions with relatively small water reserves.
-Cons / Disadvantages of Hydroelectricity
1). Flood Risk as one of the Disadvantages of Hydroelectricity
A example of this controlling effect can be cited using dams, which are used to alter water head (or level) at various points within a river or any other water body. In events of unusually excessive precipitation or damage of the hydroelectric facility, water may overflow the reservoirs and natural water basins, resulting in floods that could be severe and damaging to life and property.
The Bangiao dam failure of 1975 which led to the deaths of at least 26,000 (speculations suggest the overall death toll could be up to 240,000) in China, is a major instance of flooding hazard resulting from hydroelectricity generation facilities .
Mitigating the risk of flooding as a result of hydroelectricity generation facilities, requires careful engineering and environmental evaluations, as well as the use of optimal hydropower policies to guide such projects.
The significance of the risk and effect of flooding in relation to hydropower projects makes it one of the most critical disadvantages of hydroelectricity.
2). Aquatic-Ecosystem Disruption as one of the Disadvantages of Hydroelectricity
Another example of the most common and critical disadvantages of hydroelectricity, is its potential ecological and environmental effects.
Because hydroelectricity generation requires the construction and operation of facilities within aquatic ecosystems, the natural equilibrium of these ecosystems tend to be disrupted and altered in the process of generating hydroelectricity .
There are various ways by which hydroelectricity generation can affect the ecosystem. The most common of these, however, is the change in water flow conditions such as volume, direction, level, and velocity.
Because the activities and survival of aquatic species depend on physicochemical and biological conditions in their natural habitat, such changes are bound to affect these species.
For example, the restriction of water flow by dams and artificial reservoirs in hydropower facilities, tends to reduce the overall concentration of oxygen in the water body over a long period of time.
In some cases, oxygen concentration may fall below 5-6mg/L, which is the minimum required concentration for survival of most aquatic organisms .
With reduced oxygen levels, carbon dioxide; a greenhouse gas, may accumulate in harmful quantities as a result of natural processes like respiration and biodegradation.
In addition to being a direct threat to the survival of aquatic species, accumulation of greenhouse gases in the aquatic ecosystem may lead to atmospheric emissions and contribute to environmental challenges like global warming and climate change.
Also, the natural migration of aquatic organisms like fish may be affected by the flow-altering and restrictive effects of hydropower systems. Such impacts can lead to unfavorable consequences like species depopulation, habitat loss, and potential extinction.
Lastly, hydroelectricity generation can increase the risk of various forms of environmental degradation, such as wetland/floodplain destruction, and decline in water quality.
3). High Capital Cost as one of the Disadvantages of Hydroelectricity
Capital cost is a major deterrent in the efforts to expand hydroelectricity generation around the world.
While the subsequent operation and maintenance costs for hydropower plants are relatively low, the initial construction of these facilities typically costs several billions of dollars .
Hydropower plant construction costs can be attributed to the scale of these plants, the predominantly-aquatic construction conditions, and the need to build dams and control the flow of water.
The costs are often increased as a result of prolonged construction periods and potential delay in the construction process. Because of the need to integrate the components of hydropower plants with natural aquatic ecosystems, such extended construction periods are not uncommon.
4). Water Level Dependence and Exclusion of Arid Regions
Although hydroelectricity is geographically-versatile compared to other forms of renewable electricity, the fact that it depends on the presence or availability of significant volumes of water is often a disadvantage.
Basically, this dependence on hydrological resources means that hydroelectricity can be generated in regions with favorable hydrological conditions. While there are several of such regions on Earth, arid environments and places with unfavorable hydrology are excluded from the prospect and planning of hydropower projects.
Since these regions also require power supply, their inability to locally generate hydroelectricity is a challenge. Also, because hydroelectricity is fully dependent on water resources, events like silting and water basin expansion which affect water levels, can have negative impacts on hydroelectricity generation.
5). Land Use Challenge as one of the Disadvantages of Hydroelectricity
Because hydropower plants occupy significant area, they tend to affect land use patterns in their environs.
One way in which this occurs is the encroachment of flood plain areas by hydropower plants . This often makes it impossible for previous land use patterns in these areas to continue.
In addition to policies and regulations that control the patterns of settlement and land-use around hydropower plants, environmental changes and safety concerns (such as flood risk) can displace the human population within this vicinity.
The demand for water resources for hydroelectricity generation, when combined with policies restricting the use of water resources around hydropower plants, can also affect land use and cause migration.
6). Climate Dependence as one of the Disadvantages of Hydroelectricity
The potential effect of climate change and overall climatic conditions on hydropower plants, is one of the disadvantages of hydroelectricity.
This effect arises primarily from the fact that hydropower plants are water-dependent. When climatic fluctuations and associated events such as droughts and desertification occur, the performance of these plants and the amount of hydroelectricity which is supplied, may both be affected. Such vulnerability has a negative effect on the reliability and energy efficiency of hydroelectricity generation.
7). Potential Failure as one of the Disadvantages of Hydroelectricity
Despite the relative stability, consistency and reliability of hydropower plants, hydroelectricity supply may be altered by failure of these plants.
Various circumstances can lead to the failure of hydropower plants, including hydrological and geological changes, dam failures, climatic changes and water flow alterations. The severity and related consequences of failure generally depend on the underlying causes.
Pros or Advantages of hydroelectricity are;
- Relatively Clean
- Low Production Cost
- Economic Growth
- Hydroelectric Systems may Serve Various Purposes
- Domestic Production
- Conservative Process
- Geographic Versatility
Cons or Disadvantages of hydroelectricity are;
- Flood Risk
- Ecosystem Disruption
- High Capital Cost
- Water Level Dependence and Exclusion of Arid Regions
- Land Use Challenge
- Climate Dependence
- Potential Failure
Hydroelectricity advantages and disadvantages are a guideline for predicting potential problems, benefits and areas for improvement when developing and operating hydropower plants.
For hydroelectricity generation and supply to be optimal, these advantages must be maximized while mitigating the disadvantages. A combination of careful and effective planning, based on technical, economic, environmental and social considerations, can help to achieve this.
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