- 2077 Chaitra · 6 marks
Geothermal versus conventional thermal plant
Short answer
Geothermal uses earth's heat with nil fuel cost, low efficiency 10-20%, high capacity factor, and very low emissions, but is site-limited. Thermal plants burn coal, oil, or gas, give 30-40% efficiency, can be located flexibly, but have high fuel cost and pollution.
Compare Geothermal power plant with conventional thermal power plant considering various aspects.
A geothermal power plant uses heat from the earth (steam or hot water from wells), while a conventional thermal plant burns coal, oil or gas in a boiler. Both drive steam turbines.
Comparison
| Aspect | Geothermal plant | Conventional thermal plant |
|---|---|---|
| Heat source | Earth's internal heat | Combustion of fossil fuel |
| Fuel cost | Nil | High; major running cost |
| Renewability | Renewable if reinjected | Non-renewable |
| Location | Only at geothermal fields | Near load, port or coal mine |
| Steam condition | Low pressure and temperature (about 150–250 °C) | High pressure, superheated (about 540 °C) |
| Efficiency | Low, about 10–20% | About 30–40% |
| Unit size | Small to medium (5–100 MW) | Large (100–800 MW) |
| Boiler / fuel handling | Not needed | Boiler, coal handling, ash handling needed |
| Capacity factor | High, about 90% (base load) | About 60–85% |
| Load following | Poor; run as base load | Moderate |
| Capital cost | High (exploration and drilling risk) | Moderate |
| Emissions | Very low CO₂; some H₂S, mineral salts | High CO₂, SO₂, NOx, particulates |
| Problems | Corrosion and scaling by minerals, reservoir depletion | Fuel supply, ash disposal |
| Land use | Small | Large (fuel yard, ash ponds) |
| Life | 30–50 years (if reservoir managed) | 25–30 years |
Remarks
Geothermal is cleaner and cheaper to run but is site-limited and has lower efficiency; thermal plants are flexible in location and size but costly to run and polluting.
✓ Answer checked by Claude Opus 5.5 (high effort)
Related questions
- Thermal versus nuclear power plant · Power Plant Design, chapter 1 · asked 2×
- Thermal, geothermal and nuclear plants compared · Power Plant Design, chapter 1 · asked 7×
- Thermal, geothermal and PV plants compared · Power Plant Design, chapter 1 · asked 7×
- How a geothermal power plant operates · Power Plant Design, chapter 1
- Hydro versus thermal: techno-economic and environmental · Power Plant Design, chapter 1
- Tidal versus wind power plant · Power Plant Design, chapter 1
- Types of geothermal power plant · Energy Environment and Society, chapter 3
- Power sources and hydro versus thermal · Hydro Power, chapter 3
- Thermal plant advantages, superheating and reheating · Power Plant Equipment, chapter 7
- Simple Rankine plant 2 MPa / 20 kPa: efficiency, power · Fundamental of Thermodynamics & Heat Transfer, chapter 6