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Which of the following power plants is the most reliable ?
Diesel
Hydro-electric
Steam
Tidal
Hydro-electric
Hydro-electric power plants are considered the most reliable due to their simple mechanical construction, high operating life, and the absence of complex fuel-combustion systems. They exhibit the lowest forced outage rate compared to thermal (steam) or diesel plants because they rely on the potential energy of water rather than volatile chemical conversion processes.
Hydro-electric power plants are considered the most reliable due to their simple mechanical construction, high operating life, and the absence of complex fuel-combustion systems. They exhibit the lowest forced outage rate compared to thermal (steam) or diesel plants because they rely on the potential energy of water rather than volatile chemical conversion processes.
P=╧БgQH╬╖ тАФ power output where ╧Б is density, g gravity, Q discharge, H head, and ╬╖ efficiency
The principle involves converting potential energy of stored water (at a high head) into kinetic energy through penstocks. This water strikes the turbine blades, converting kinetic energy into mechanical rotation, which the coupled generator then converts into electrical energy. The absence of boilers, fuel supply systems, and complex heat-exchanger maintenance ensures maximum availability.
Hydro-electric plants have extremely low maintenance requirements compared to steam plants.
They provide the fastest start-up and synchronization time (often less than 5 minutes).
Availability factor is significantly higher than steam or diesel power plants.
Hydro plants are environmentally clean and do not suffer from fuel storage or transportation issues.
Longest operational life (40-60+ years)
Fastest response to load changes
Lowest operating cost per kWh
No air pollution emissions
High initial capital investment for dam construction
Location-specific (requires favorable geography and water availability)
Significant environmental and social impact due to displacement
Base load and peak load operation in regional grids
Frequency regulation and grid stabilization
| Feature | Diesel Plant | Hydro-electric |
|---|---|---|
Starting Time | Diesel (Fast) | Hydro (Fast) |
Maintenance | High | Low |
Steam power plants are reliable but require complex maintenance for boilers and auxiliary systems, leading to more forced outages.
Diesel plants are reliable for small-scale/standby power but are impractical for base-load bulk power due to high fuel costs.
B is correct тАФ Hydro-electric plants are the most reliable due to their simple construction, minimal auxiliary system dependencies, and lack of thermal combustion-related downtime.
In competitive exams, if asked for 'fastest starting' plant, Hydro and Gas Turbine are primary candidates; if asked for 'most reliable', Hydro is the standard answer.