Differentiate between overhead transmission and underground transmission.
2 Answers
Certainly! Here’s a comparison of overhead and underground transmission systems:
### Overhead Transmission
**1. **Cost:** Typically less expensive to install and maintain compared to underground systems. This is due to lower material costs and easier access for repairs.
**2. **Maintenance:** Easier to inspect and repair because the lines are exposed. However, they are susceptible to weather-related damage (e.g., storms, ice).
**3. **Reliability:** More prone to outages caused by environmental conditions like high winds, lightning, and ice accumulation.
**4. **Environmental Impact:** Can be more visually intrusive and may affect local landscapes. Wildlife can also be impacted by the lines.
**5. **Space:** Requires more space due to the need for towers and clearance around the lines.
**6. **Heat Dissipation:** Overhead lines have better heat dissipation, which allows them to carry more current over long distances without overheating.
### Underground Transmission
**1. **Cost:** More expensive to install due to excavation, insulation, and specialized equipment. Maintenance can also be costly.
**2. **Maintenance:** Harder to access and repair, which can lead to longer downtimes. However, they are less affected by weather conditions.
**3. **Reliability:** Generally more reliable as they are protected from weather-related damages and environmental hazards.
**4. **Environmental Impact:** Less visually intrusive and can improve the aesthetic quality of an area. They also minimize the impact on wildlife.
**5. **Space:** Requires less surface space as cables are buried underground.
**6. **Heat Dissipation:** Heat dissipation is more challenging in underground systems, which can limit their current-carrying capacity. Special cooling methods might be necessary.
In summary, overhead transmission is typically favored for its lower cost and simpler maintenance, while underground transmission is preferred in urban areas or places where aesthetics and reliability are prioritized despite the higher cost.
### Overhead Transmission
**1. **Cost:** Typically less expensive to install and maintain compared to underground systems. This is due to lower material costs and easier access for repairs.
**2. **Maintenance:** Easier to inspect and repair because the lines are exposed. However, they are susceptible to weather-related damage (e.g., storms, ice).
**3. **Reliability:** More prone to outages caused by environmental conditions like high winds, lightning, and ice accumulation.
**4. **Environmental Impact:** Can be more visually intrusive and may affect local landscapes. Wildlife can also be impacted by the lines.
**5. **Space:** Requires more space due to the need for towers and clearance around the lines.
**6. **Heat Dissipation:** Overhead lines have better heat dissipation, which allows them to carry more current over long distances without overheating.
### Underground Transmission
**1. **Cost:** More expensive to install due to excavation, insulation, and specialized equipment. Maintenance can also be costly.
**2. **Maintenance:** Harder to access and repair, which can lead to longer downtimes. However, they are less affected by weather conditions.
**3. **Reliability:** Generally more reliable as they are protected from weather-related damages and environmental hazards.
**4. **Environmental Impact:** Less visually intrusive and can improve the aesthetic quality of an area. They also minimize the impact on wildlife.
**5. **Space:** Requires less surface space as cables are buried underground.
**6. **Heat Dissipation:** Heat dissipation is more challenging in underground systems, which can limit their current-carrying capacity. Special cooling methods might be necessary.
In summary, overhead transmission is typically favored for its lower cost and simpler maintenance, while underground transmission is preferred in urban areas or places where aesthetics and reliability are prioritized despite the higher cost.