Throughout history, people have been using rivers and streams to help them in their work. For example, ancient civilizations used the energy of river currents to crush grain and make low-fat bran muffins. Others used the power of moving water to drive mills for grinding grains into flour. Hydroelectric Power Advantages will be covered in this post as well as the disadvantages.
Today, modern people use moving water to produce electricity. As such, they prevent the burning of 120 million tons of coal and 22 billion gallons of oil every year. Alternative energy sources such as Solar Energy and wind turbine energy are some of the other green energy sources that are perfect for most homeowners.
Hydropower is a source of energy widely used around the world. In fact, it represents 17% of total electricity production. The leading hydropower producer is China, followed by Canada, Brazil, and the US.
Hydropower has several advantages. In this post, we discuss the advantages and disadvantages of hydroelectric power.
Hydroelectric Power Pros
The first hydroelectric power plant in the world began operating in 1882 along the Fox River in the US. Today, over 8,000 individual hydropower stations are producing more than 1 MW representing 89% of the global capacity.
The following are the pros of hydroelectric power.
1. Renewable Energy Source
Hydroelectric power is a renewable source of energy. Why you may ask. This is because it involves harnessing energy from flowing water. Water vaporizes into clouds, and when rain falls, it’s recycled back to the surface of the Earth.
This is the water cycle. When it rains, flowing water becomes streams and, eventually, rivers. In order to produce electricity, dams are usually constructed. Turbines are set up along the flow of water. These rotating turbines harness the kinetic energy of flowing water. They trigger the generator to rotate, producing electricity.
The water usually exits the turbine and continues to flow to the river below the dam. Thanks to the water cycle, rivers are continually revitalized and can help in generating more power over and over.
Fossil fuels, such as oil and coal, are non-renewable. Once mined and burned, it takes thousands or even millions of years for new deposits to form. This means coal and oil have an expiration date, unlike rivers.
What you need to know is that hydroelectric power plants with accumulation reservoirs offer operational flexibility. This is because they can respond to fluctuations when it comes to demand for electricity.
2. Clean Energy Source
When burning coal, it reacts with oxygen through a chemical reaction. This chemical reaction converts the stored solar energy into thermal energy, releasing it as heat. During this process, the emission of greenhouse gases such as methane and carbon dioxide occurs.
Carbon dioxide and methane are harmful to the environment. First off, carbon dioxide increases the greenhouse effect. This is where more thermal energy gets trapped by the atmosphere. As such, it results in the planet becoming warmer.
Methane also has a similar effect when released into the atmosphere in large quantities. This contributes to climate change.
Hydroelectric power is a clean source of energy, unlike oil and coal. First off, hydroelectric power plants do not produce greenhouse gases. Since they produce little or no greenhouse gases, they help to improve air quality.
They also help in mitigating smog, climate change, and acid rains. Based on studies, hydropower prevents the emission of greenhouse gases and the burning of 4.4 million barrels of oil each day.
3. Contributes to the Storage of Drinking Water
One main reason why a government will build a hydroelectric dam is to produce electricity. Other reasons include flood control, irrigation, and water supply. Speaking of water supply, reservoirs provide water for domestic and industrial use.
Domestic use of water includes drinking, bathing, cooking, washing, and even garden watering. Without reservoirs, cities around the world would find it challenging to supply drinking water to the residents.
To ensure the water is safe for drinking, engineers place a floating mechanical de-stratifier at the deepest part of the reservoir. This device works by pulling surface water down. As such, it helps to mix the different water layers generating an even temperature.
Water flows through an intake tower for screening before rushing to the treatment plant. At the treatment plant, it passes through the filtration area. This area has polymer membrane filters, which helps in removing impurities of less than 2 microns. These fine straw-like fibres also remove micro-organisms.
The use of the polymer membrane filters eliminates the need to add chemicals in the water. To clean the filters, they are usually backwashed. The backwashed water then flows back into the treatment plant for processing.
4. Offers a Variety of Recreational Activities
There are more than 850,000 dams across the world. They are primarily built across more than 60% of rivers and streams worldwide. About 50,000 of these dams are large. These dams have become multi-purpose.
They have become prime recreational areas for the residents as well as tourists. People can sailboats, camp, ski, have a picnic, or even fish. To experience these public recreational facilities, one needs a license from the state park office.
This license authorizes the holder to launch boats, swim, fish, or even kayak on the lake. Thanks to the recreational activities on the reservoir, it helps to open up remote places. First off, the rural town will benefit from roads connecting to the national highway network.
This allows residents and tourists to travel with ease. Improved road networks and the availability of affordable electricity results in industrialization. Investors will set up industries to manufacture goods at affordable costs before selling to consumers.
Other benefits include improving health care, access to quality education, and improved quality of life. All these activities help to uplift the economy of a remote town or village.
5. Relatively Low Maintenance and Operation Costs
Dams are complex structures. To build one, you need vast amounts of manpower, investment, and raw materials. The first step is to de-water the river. This process involves diverting a river through a tunnel running around the site.
The diversion tunnel is usually lined with concrete to prevent collapse. A cofferdam is a next step. Built upstream of the construction site, it helps to funnel water into the diversion tunnel. Engineers will proceed to remove loose rock on the river bed before constructing a plinth which prevents water from leaking.
After constructing a plinth, engineers will begin building a concave curved downstream surface. This helps to absorb the constant pressure of water. Afterwards, reinforced steel and an enclosure filled with concrete help to strengthen the dam.
Thanks to careful planning and the use of high-quality materials plus machinery, dams can last for 50 years to 100 years. To ensure the dam lasts long, maintenance should be a routine. It should involve the inspection of the structure and proper maintenance of other components.
Loss of a reservoir will result in loss of life, loss of income, and property damage. This will cause hardship for the people dependent on the lake for water, recreation, and power.
6. Pairs Well With Other Renewable Energy Sources
Solar and wind energy are among the best renewable energy sources that provide clean energy. The problem is, they are non-dispatchable energy sources. This means that solar and wind energy are not reliable when it comes to the production of electricity 24/7.
First off, solar PV systems experience a decline in power production on cloudy and rainy days. Based on research, a solar panel produces 290 to 360 watts of power.
Wind turbines also experience a decline in power production when the wind is not blowing. A typical wind turbine with a capacity of 2.5 to 3 MW produces more than 6 million kWh in a year. This is enough to supply 1,500 average homes with electricity.
The good news is when the sun shines, and the wind blows, solar PV systems and wind turbines produce lots of electricity. To ensure the excess electricity does not go to waste, solar PV owners can share it with the grid. In turn, the utility provider offers credit.
Hydropower can meet peak demand with ease. This is because the flow of water to the turbines remains steady during peak demand hours. As such, power generation and supply to homes, businesses, and industries continue.
Hydroelectric Powers Cons
1. Can Trigger off Conflict
Building dams across rivers is beneficial to a country. It improves the quality of life for its residents. It opens up remote areas by connecting to highways and the rail network. While reservoirs are multi-purpose, they can trigger off conflict.
For starters, building a dam interrupts the natural water flow from one region to another. If a town or city downstream depended on it for fishing and water supply, it means a scarcity of water will hit the town or city.
Let’s assume the river is a significant tributary flowing into a large river crossing different countries. Building a dam across the tributary can trigger off conflict. This can even spark a civil war if no diplomatic solution is ever found.
Apart from the scarcity of water, people living downstream are vulnerable to floods. This is common during heavy rains.
In 1968, the Norwegian government came up with a plan to build a dam and hydroelectric power station in Altaalven. The project included the building of a 110 m high dam. By doing so, it would put the entire Sami village underwater. Massive protests broke out, turning out to be a complex conflict.
2. High Capital Costs
Hydroelectric power plants and dams are expensive to build. They are costly to construct due to logistical challenges. They include materials, laying the foundation, diverting the river and topography.
The largest dam in the world is the Three Gorge in China. The government estimated it would cost 180 billion yuan or $22.5 billion to construct it. By 2008, the costs rose to 148.365 billion yuan.
The government spent 64.613 billion yuan on construction, 68.557 billion yuan relocating people, and 15.195 billion yuan on financing. They estimated that the recovery of the construction cost would happen after the dam generated 1,000 terawatt-hours.
The good news is, the full cost recovery happened in December 2013, a year after it became fully operational.
The second-largest dam in the world is the Itaipu Dam in Brazil. Constructed on the Parana River, construction costs were $19.6 billion (1984 dollars). Today, the dam generates 96.586 TWh a year.
Despite the high upfront capital costs, the dams cost little to maintain.
3. Environmental Damage
Hydroelectric power is a renewable energy source, but it has severe environmental impacts. Most importantly, building dams across rivers interrupts their natural flow. As such, it influences the movement of fish as they migrate. As you already know, fish environments are usually influenced by several factors.
They include water levels, safe spots, and water speeds. If an interruption occurs to one of these factors, it will alter the ecosystem and fish environment. Lots of fish and other marine animals migrate when there is a food shortage.
Others migrate when breeding season begins. Building a dam across the river cuts off the fish and marine animals from their breeding grounds and food sources. This leads to little or no reproduction of fish as well as fish deaths.
Apart from disrupting fish migratory routes, building dams lead to human and animal displacement. When the dam blocks the river, flooding of large tracts of land occurs. This destroys homes, businesses, and animal habitats.
Displaced people change their customs and lifestyles. Based on research, dams displaced more than 80 million people worldwide.
Reducing The Need For Energy Consumption
With energy consumption and the types of energy sources being used affecting our planet, it is essential to reduce energy consumption. In order to reduce energy consumption, we need to look at ways to build homes that are more energy-efficient.
Firstly homes should be built with double glazed windows to reduce as much as 30% of all heat loss and gain in the home. Secondly, roof insulation products like Aerolite Insulation or Isotherm Insulation should be fitted in order to reduce 40% heat loss and gain via the ceiling. Thirdly home appliances that are EnergyStar rated are important as they reduce energy consumption.
Hydroelectric power is a clean and renewable energy source. It pairs well with wind energy and solar technologies. By doing so, it’s able to meet the peak electricity demand for residents and businesses.
On the downside, it adversely impacts the environment, displaces people and animals. Many people argue that the disadvantages of hydroelectric power plants can be sufficiently mitigated. For example, engineers can locate dams strategically to allow fish passages. Or they can add special water intakes to ease water released from a dam.
By complying with safety requirements, hydroelectric dams will not compromise the people, animals, and environment.