JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD B.Tech II Year POWER SYSTEMS - I Previous Question Paper (November/December - 2020 - R15)

The selection of a site for a thermal power station is critical for economic operation and reliability. The primary factors include:

1. Proximity to Fuel Supply: Since thermal plants consume massive quantities of coal, the site should be near coal mines to minimize transportation costs and avoid supply chain disruptions.
2. Availability of Water: A large volume of water is required for steam generation and, more importantly, for condenser cooling. The plant should be located near a river or large water body.
3. Transportation Facilities: Adequate rail and road connectivity is essential for transporting heavy machinery during construction and for the continuous supply of fuel and spare parts.
4. Cost and Type of Land: The land must be inexpensive, vast enough for the plant, coal storage, and ash disposal, and possess high load-bearing capacity to support heavy equipment.
5. Ash Disposal Facilities: Thermal plants produce significant amounts of ash. A site must have sufficient low-lying land nearby for ash dumping or a system for transporting it to brick manufacturers.
6. Proximity to Load Centers: The plant should be reasonably close to the load center to reduce transmission losses and costs, though this is often secondary to fuel and water availability.
7. Environmental Regulations: The site must comply with pollution control norms regarding air quality and thermal discharge into water bodies to minimize ecological impact.

Gas power stations offer specific operational characteristics compared to other thermal plants:

Advantages:

• Low initial capital cost and faster installation compared to coal-fired plants.
• High efficiency when operated in a combined cycle mode.
• Quick starting and stopping capabilities, making them ideal for peak load demand.
• Requires less space and has lower maintenance costs due to the absence of boilers and coal handling equipment.
• Minimal environmental impact regarding ash production and lower sulfur emissions.

Disadvantages:

• High cost of fuel (natural gas) makes base-load operation uneconomical.
• Limited availability and dependence on gas pipelines or LNG terminals.
• Shorter life span of components due to high operating temperatures.
• Efficiency is highly sensitive to ambient air temperature.