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Pros and Cons of Hydroelectric Energy

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Hydro Electric Energy

Hydro Electric Energy is second largest source of electricity in the world accounting for roughly 20% of the worldwide demand of electricity with around 800 GW of capacity installed. Hydroelectricity power plants are the biggest power stations in the world dwarfing the biggest nuclear and coal power projects. The world’s biggest power plant is the Three Gorge Dam in China which at 22.5 GW is more than 50% larger than the 2nd biggest power station in the world. China is the by far the world leader in hydro power plant capacity with around 200 GW which it aims to double to around 400 GW  by 2020. The advantages of hydroelectricity energy are substantial enough to far outweigh any disadvantages. But like nuclear energy, hydro power has some tail risks which can lead to catastrophic damage.

Pros of  Hydroelectric Energy

  1. Carbon Neutral– Note Hydro Electric  Energy results in no new net GHG emissions as it is part of the carbon cycle. Unlike coal and others forms of fossil fuel which have been buried millions of years ago and burning them adds to carbon in the atmosphere, responsible biomass energy generation results in no new carbon emissions or pollution.
  2. Continuous Source of Power – Hydro Electric Energy can be generated almost 24×7  unlike other forms of renewable energy like wind and solar that are intermittent in nature.
  3. Can be built on small scale – Hydroelectric Energy Power Plants can be built in 1 MW sizes unlike other types of power which require much larges scale. For example nuclear energy requires a typical plants size of at least 500 MW to make it economical.
  4. Reliability – Hydroelectric Energy is a highly reliable form of energy almost as good as other fossil fuel energy forms like coal, gas etc. Hydroelectric Energy Power Plants except in drastic situations continue to run reliably for the whole day without any changes.
  5. Low Electricity Cost – Hydroelectric Energy Electricity Cost is quite low at around 3-5c/Kwh making it very attractive to construct hydro plants. Nuclear  Plants also  have long lives of between 40-60 years which means that they are extremely profitable once constructed within reasonable costs.
  6. Long Life – Hydro Plants  has a very long life of around 50- 100 years which is much longer than that of even Nuclear Power Plants. The long life implies that the life cycle cost of a Hydel Power Plant becomes very low in the long term.
  7. High Load Factor – The Load Factor for Solar and Wind Energy ranges from 15-40% which is quite low compared to Fossil Fuel Energy. Hydroelectricity on the other hand  has a load factor of almost 40-60%.
  8. Energy Storage – Pumped Hydro Storage is possible with most of the hydro power plants. This makes them ideal storage for wind and solar power which are intermittent in nature. Hydro Dams can be modified at low costs to allow pumped storage.
  9. Low Operating Costs and little Maintenance – Operating labor cost is also usually low, as plants are automated and have few personnel on site during normal operation.
  10. No Fuel Cost – Hydro Energy does not require any fuel like most other sources of energy. This is a huge advantage over other fossil fuels whose costs are increasing at a drastic  rate every year. Electricity prices are increasingly rapidly in most parts of  the world much faster than general inflation. Price shocks due to high fuel costs are a big risk with fossil fuel energy these days.

Cons of  Hydroelectric Energy

  1. External Costs of Hydroelectricity  Besides the normal cots of  hydroelectricity, there are external costs to hydroelectricity as well. The massive displacement of people due to the creation of reservoirs, wildlife affects, potential losses from catastrophic failure should also be factored in. However in the real world these costs are not added as the society bear the external costs while the hydroelectricity owners only bear the normal intrinsic costs.
  2. Cannot be Built Anywhere – This disadvantage of Hydroelectric Energy is present with other forms of Energy as well. Some forms of Energy are just better suited to some places. For example you can’t build a nuclear plant on top of an earthquake prone region,you can’t build a wind farm near the Dead Sea etc.
  3.  Land usage and Loss of Scenery – Hydroelectric Energy can sometimes use large amounts of land if not properly planned and built. The construction of roads to access the Dams also takes up some land.
  4. Effect on Marine Life – The operation of commercial Hydroelectric Energy Stations has known to moderately affect the marine life around the Power Plant. It leads to disruption in movement and growth of fishes and other marine life. Turbines can also kill fish passing through it.
  5. Long Gestation Time and Project Delays – The cost and time overruns can be huge for Hydroelectric Energy Power Plants can sometimes lead to great problems. Big Hydel Power Plants take around 4-6 years to be built.
  6. Tail Risk, Dam Failure – Because large conventional dammed-hydro facilities hold back large volumes of water, a failure due to poor construction, terrorism, or other cause can be catastrophic to downriver settlements and infrastructure. Dam failures have been some of the largest man-made disasters in history. The Banqiao Dam failure in Southern China directly resulted in the deaths of 26,000 people, and another 145,000 from epidemics.
  7. Earthquake Vulnerability – Large Dam Construction has been linked to increased propensity of Earthquakes. Massive Earthquakes in China and Uttarakhand in India were linked to the building of Massive Dams in these countries.
  8. Environmental, Dislocation and Tribal Rights – Large Dam construction especially in populated areas leads to massive Tribal Displacement, Loss of Livelihood and Religious Infringement as potentially sacred Land is occupied by the Government.



Abhishek Shah

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