Introduction:
Hydel power plants, also known as hydroelectric power plants, generate electricity using the power of flowing or falling water. While they have several advantages, such as being a renewable energy source and having low operational costs, they also have certain disadvantages when compared to other types of power plants.

Economics:
One of the most significant disadvantages of hydel power plants is the economics involved in their setup and operation. Hydel power plants require a significant amount of investment for construction, including the building of dams, reservoirs, and other infrastructure. These costs can be quite high, especially for large-scale projects. Additionally, the maintenance and operation costs of hydel power plants can also be substantial. Therefore, the economics play a crucial role in determining the choice of power plant.

Nearness to Load Centre:
When it comes to the nearness to the load center, hydel power plants may not always have an advantage. Load centers are areas where electricity demand is the highest, such as cities or industrial hubs. While it is possible to build hydel power plants near load centers, this is not always feasible due to geographical constraints. Hydel power plants require a suitable water source, which may not always be available near load centers. As a result, transmission lines need to be constructed to transport the electricity from the power plant to the load center. This adds to the overall cost and complexity of the power generation and distribution system.

Cost of Energy Resource:
In terms of the cost of the energy resource itself, hydel power plants have an advantage over fossil fuel-based power plants. Water, being a renewable resource, is freely available in nature. Once the initial investment is made for constructing the hydel power plant, the cost of the energy resource is relatively low. In contrast, fossil fuels such as coal or natural gas used in thermal power plants need to be purchased, and their prices can be volatile. However, it is important to note that the overall cost of a hydel power plant, including the construction and maintenance costs, may still make it less economically favorable compared to other types of power plants.

Technical Skill Required:
In terms of technical skill required, hydel power plants can be complex to design, construct, and operate. They involve various engineering disciplines, including civil, mechanical, and electrical engineering. The construction of dams, tunnels, and associated infrastructure requires expertise in civil engineering. Additionally, the operation and maintenance of the turbines, generators, and electrical systems require skilled technicians and engineers. While other types of power plants also require technical expertise, the unique challenges and complexities associated with hydel power plants may require specialized skills and knowledge.

Conclusion:
While hydel power plants have several advantages, including being a renewable energy source and having low operational costs, they also have certain disadvantages. The economics involved in their setup and operation, the challenges of being near load centers, the technical skills required, and the cost of the energy resource itself are factors that need to be considered when determining the choice of power plant. Ultimately, the decision should be based on a comprehensive evaluation of these factors to ensure the most economically viable and sustainable solution for power generation.

Disadvantages of Hydel Power Plants Compared to Other Power Plants

Hydel power plants, also known as hydroelectric power plants, utilize the energy of flowing or falling water to generate electricity. While hydel power plants have numerous advantages such as being a renewable energy source and having low operational costs, they also have several disadvantages when compared to other types of power plants. The correct answer to the question is option 'D', which highlights the economics that determine the choice of power plant. Let's explore this answer in detail:

1. Higher Initial Cost:
- Hydel power plants require significant upfront investments in terms of construction and infrastructure development.
- The cost of building dams, reservoirs, turbines, and transmission lines can be substantial.
- This higher initial cost makes hydel power plants less economically feasible in certain locations compared to other types of power plants.

2. Limited Suitable Locations:
- Hydel power plants require a large and consistent water source such as a river or a lake.
- Identifying suitable locations with adequate water resources can be challenging and limited in many regions.
- This restricts the widespread deployment of hydel power plants compared to other types of power plants that can be set up in various locations.

3. Environmental Impact:
- The construction of dams and reservoirs for hydel power plants can result in the displacement of local communities and the loss of habitats for wildlife.
- The alteration of natural water flows can also impact aquatic ecosystems and fish populations.
- The environmental impact associated with hydel power plants can create opposition from environmentalists and local communities, which can further delay or hinder their development.

4. Dependence on Water Availability:
- Hydel power plants rely on the availability of water for their operation.
- In regions experiencing droughts or water scarcity, the power generation capacity of hydel plants can be significantly reduced.
- This dependence on water availability makes hydel power plants less reliable compared to other types of power plants that are not affected by water availability.

5. Longer Construction Time:
- The construction of hydel power plants involves complex engineering and extensive infrastructure development.
- This often leads to longer construction times compared to other types of power plants.
- The extended construction period can delay the generation of electricity and the realization of returns on investment.

6. Impact on Land and Habitats:
- Building dams and reservoirs for hydel power plants requires a large area of land, which can lead to the displacement of local communities and the loss of agricultural or forested areas.
- The alteration of river flows and the creation of reservoirs can also result in the flooding of habitats and the loss of biodiversity.
- The impact on land and habitats can be a significant disadvantage of hydel power plants compared to other power plants that may have a lesser impact on the environment.

In conclusion, while hydel power plants have several advantages, such as being a renewable energy source and having low operational costs, they also have several disadvantages when compared to other types of power plants. The economics, including the higher initial cost, limited suitable locations, environmental impact, dependence on water availability, longer construction time, and impact on land and habitats, contribute to the disadvantageous nature of hydel power plants in terms of determining the choice of plant.