How much is the world's electricity supplied by Hydroelectric Power Plants?


To add a 2700 TWH is generated every year. Hydropower supplies at least 50% of electricity production in 66 countries and at least 90% in 24 countries.




What are the different types of Hydroelectric Power Plants?


There are basically four types of power plants: - 1. Pelton turbines - It is impulse turbine which is normally used for more than 250 m of water head.
2. Francis - This is a reaction turbine which is used for head varying between 2.5m to 450m.
3. Kaplan - It is propeller type of plant with adjustable blades which are used for heads varying between 1.5 m to 70 m.
4. Propeller - It is used for head between 1.5 to 30 m
5. Tubular - This is used for low and medium height projects. Normally for head less than 15 m.




What are the major components of a Hydroelectric Power Plant?


The major components of a Hydroelectric Power Plant are:-
1. Dam/Barrage
Head works i.e. power intake, head regulator and desilting chambers etc.
2. Head race tunnels/channels
3. Surge shaft/surge chambers
4. Pressure shaft/Penstock
5. Underground and surface power house
6. Tailrace channel or tailrace tunnel.




What is the classification of Hydro Projects based on Installed Capacity?


Micro: upto 100 KW
Mini: 101KW to 500 KW
Small: 500 KW to 7 MW
Medium: 7 MW to 25 MW
Mega: Hydro projects with installed capacity >= 500 MW




How energy is generated in Hydroelectric Power Plant?


A hydroelectric power plant consists of a high dam that is built across a large river to create a reservoir, and a station where the process of energy conversion to electricity takes place. The first step in the generation of energy in a hydropower plant is the collection of run-off of seasonal rain and snow in lakes, streams and rivers, during the hydrological cycle. The run-off flows to dams downstream. The water falls through a dam, into the hydropower plant and turns a large wheel called a turbine. The turbine converts the energy of falling water into mechanical energy to drive the generator After this process has taken place electricity is transferred to the communities through transmission lines and the water is released back into the lakes, streams or rivers.This is entirely not harmful, because no pollutants are added to the water while it flows through the hydropower plant.




Which is the largest Hydropower station in the world?


Three gauges project in China on Yang-Yang river is the largest power station in the world having installed capacity of around 18,200 MW.




What is Internal Rate of Return (IRR)?


It is interest rate that makes NPV of all cash flows of a project equal to Zero. Essentially this is the return that a project would earn if it invest money in itself rather than elsewhere. This is the rate which equates discounted cash outflows flows & discounted cash inflows. Higher the IRR of the project better is the financial return on the Investment




What is Net Present Value (NPV)?


NPV is present value of future cash flows. NPV compares value of money today to the value of that money in the future taking inflation & returns into account. If the NPV of a project is positive then the project is financially viable. If NPV of a project is negative the project is not viable.




What are the 'pass through' components in the tariff of Hydro Generating Stations?


Tax on income, Extra Rupee Liabilities (FERV) are pass through components in tariff i.e. they are to be reimbursed separately to the Hydro Generating Stations as per Actuals.




What is Availability Based Tariff (ABT)?


ABT means It is a performance-based tariff for the supply of electricity by generators owned and controlled by the central government.
It is also a new system of scheduling and despatch, which requires both generators and beneficiaries to commit to day-ahead schedules.
It is a system of rewards and penalties seeking to enforce day ahead pre-committed schedules, though variations are permitted if notified One and one half hours in advance.
The order emphasises prompt payment of dues. Non-payment of prescribed charges will be liable for appropriate action under sections 44 and 45 of the ERC Act.
It has three parts:
- A fixed charge (FC) payable every month by each beneficiary to the generator for making capacity available for use. The FC is not the same for each beneficiary. It varies with the share of a beneficiary in a generators capacity. The FC, payable by each beneficiary, will also vary with the level of availability achieved by a generator.
- In the case of thermal stations like those of NLC, where the fixed charge has not already been defined separately by GOI notification, it will comprise interest on loan, depreciation, O&M expenses, ROE, Income Tax and Interest on working capital.
- In the case of hydro stations it will be the residual cost after deducting the variable cost calculated as being 90% of the lowest variable cost of thermal stations in a region.
- An energy charge (defined as per the prevailing operational cost norms) per kwh of energy supplied as per a pre-committed schedule of supply drawn upon a daily basis.
- A charge for Unscheduled Interchange (UI charge) for the supply and consumption of energy in variation from the pre-committed daily schedule. This charge varies inversely with the system frequency prevailing at the time of supply/consumption. Hence it reflects the marginal value of energy at the time of supply.
What are the components of Bulk Electricity tariff of Hydro Plants? Hydro tariff means Annual Fixed Charges (AFC) in respect of each Hydro Generating Stations which is determined by the appropriate Regulatory Electricity Commission. The components of AFC are:
1. Interest on Loan Capital
2. Depreciation & Advanced Against Depreciation
3. Return on Equity
4. Operation and Maintenance expenses
5. Interest on Working Capital.
The AFC is recovered in the form of Capacity and Primary Energy Charges.




What are approaches to tackle sedimentation problem of reservoir?


The following are some approaches to tackle sedimentation problem of reservoir:- Catchment Area Treatment (CAT) for reduction of silt load includes forestations of the catchment area and constructions of check dams on the tributaries and upstream of the river.
Effective desilting arrangements for prevention of silt.
Silt resistant equipments of withstanding the silt.
Effective operation of the reservoir to minimize silt deposition




Why Hydropower stations are preferred solution for meeting peak loads in grids?


Due to its unique capabilities of quick starting and closing, hydropower stations are found to be economical choice to meet peak load in the grid.




Which is the largest Operating Hydro Power Station in the World?


The world's Largest Hydro Electric Power Station is ITAIPU with installed capacity of 12600 MW and a reliable output of 75,000 MU in a year. It is located at the Border of Brazil and Paraguay.




What are the different types of Hydro Schemes?


Different types of Hydro Schemes are : i. Purely Run - of - River Power Station. ii. Storage type Power Station. iii.Run - of - River Stations with Pondage.




What is the record completion period of a Hydro Power Station in India of more than 100MW ?


Chamera - II HE Project (300 MW) in Distt. Chamba, HP. has been completed in a record period is Four & Half years .




What is the estimated total Hydropower potential of India?


The hydropower potential of India is around 1,45,000 MW and at 60% load factor, it can meet the demand of around 85, 000 MW.




How much of the total Hydropower potential has been exploited so far in India?


Around 26%





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