Hydro Power is one of the largest sources of energy accounting for roughly 20% of the worldwide demand of electricity and for well resourced countries it accounts for majority of the energy.For Paraguay 100% of the electricity comes from hydro power and lot of it is exported as well.Compared to other sources of Energy, Hydroelectric Power is one of the cheapest,non Carbon Emitting,non Polluting,Mature Energy Sources.Hydro Power plants have been developed to almost full potential in developed countries because of their superior characteristics and many more are being constructed by developing countries like China and India.However Hydro Power like all other thins in life suffers from disadvantages as well.The failure of a Hydro Dam can result in massive losses of human life and cause widespread devastation.Large Dams have always been controversial leading to displacement of people and ecology.They have also been cited as the reason for earthquakes due to large land changes.Here is a list of the advantages and disadvantages of Hydro Power
Hydroelectric Energy Advantages
- 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
- 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.
- Low Electricity Cost – The Electricity produced from Hydro Power is quite low making it very attractive to construct hydro plants.The payback period is estimated to be between 5-8 years for a normal hydro power plant.Hydro Plants also have long lives of between 50-100 years which means that they are extremely profitable
- No Greenhouse Gas Emissions/Air Pollution – Hydroelectricity does not produce any GHG emissions or cause air pollution from the combustion of fossil fuels unlike coal,oil or gas.This makes them very attractive as a source of cheap,non carbon dioxide producing electricity.
- 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.
- Small Size Possible - Hydroelectricity can be produced in almost any size from 1 MW to 10000 MW which makes it very versatile.Small Hydro Plants are being encouraged by government as they cause less ecological affects than large hydro plants.Even micro hydro plants are possible
- Reliability - Hydro Power is much more reliable than wind and solar power though less than coal and nuclear as a baseload source of power.Hydroelectricity is more or less predictable much in advance though it can decrease in summer months when the water is low in the catchment areas.
- 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% .
- 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 lifecycle cost of a Hydel Power Plant becomes very low in the long term
Hydroelectric Energy DisAdvantages
1) 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.
2) Wildlife and Fishes get Affected - The Fishes are the most affected species from Dam Construction as the normal flow of the river is completely changed form its river character to a lake one.Submergence of land also leads to ecological destruction of the habitat of land based wildlife.
3) 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
4) Siltation When water flows it has the ability to transport particles heavier than itself downstream. This has a negative effect on dams and subsequently their power stations, particularly those on rivers or within catchment areas with high siltation
5) 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.
6) Cannot be Built Anywhere - This disadvantage of Hdyro 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.Hydro Energy can only be built in particular places though enough of those places exist globally
7) Long Gestation Time - The time to construct a large hydro power project can take between 5-10 years which leads to time and cost overruns.