---
title: "Biomass compared with geothermal energy"
subject: "Power Plant Design"
chapter: 1
key: "semester_8/power_plant_design:bioenergy-vs-geothermal"
source: https://www.bctengineer.com/q/semester_8/power_plant_design/bioenergy-vs-geothermal
site: BCT Engineering
---

# Biomass compared with geothermal energy

Power Plant Design · Chapter 1: Energy Sources and Electric Power Generation

- Asked in: 2070 Magh, 2+6 marks
- Video: [Unit 2 Segment 3 Biomass & geothermal](https://www.youtube.com/watch?v=ZXQdyuVUwh0) — Daniall Poulsen
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_8/power_plant_design/bioenergy-vs-geothermal
- Whole chapter: https://www.bctengineer.com/md/semester_8/power_plant_design/chapter-1

## Question

What is bio energy? Discuss the advantages and disadvantages of biomass in comparison with geothermal energy.

## Short answer

Bio-energy is energy from biomass. Compared to geothermal, biomass is widely available, uses simple technology, and provides storable fuel and multiple products, but has low energy density, seasonal supply, and causes air pollution. Geothermal offers continuous, concentrated power with low emissions but is site-specific and requires high capital.

## Answer

**Bio-energy** is energy obtained from biomass (wood, crop residues, animal dung, energy crops and organic waste), either directly as heat or converted to biogas, liquid fuels or electricity. **Geothermal energy** is heat from the earth's interior, taken out as hot water or steam.

#### Advantages of biomass compared with geothermal
1. **Available everywhere** – biomass is found in every village; geothermal is limited to volcanic or hot-spring regions.
2. **Simple, low-cost technology** – stoves, biogas digesters and small gasifiers can be built locally; geothermal needs deep drilling and costly exploration.
3. **Storable and transportable** – wood, briquettes and biogas can be stored and moved to where they are needed; geothermal heat must be used near the well.
4. **Scalable** – from a single household stove to a multi-MW plant.
5. **Multiple products** – heat, electricity, liquid fuels, and fertiliser (slurry).
6. **Waste management** – turns agricultural and animal waste into energy.
7. **Rural employment** – collection, processing and plantation.

#### Disadvantages of biomass compared with geothermal
1. **Low energy density** – large volume and mass are needed; geothermal steam is a concentrated source.
2. **Fuel supply needed** – collection, transport and storage cost; geothermal fuel is free and continuous.
3. **Lower efficiency** – traditional burning is about 10–15% efficient.
4. **Seasonal and variable supply** – crop residues are seasonal; geothermal gives steady base load (capacity factor about 90%).
5. **Air pollution** – smoke, particulates and indoor pollution; geothermal emissions are small (mainly H₂S).
6. **Land use** – competes with food crops and forests; deforestation if over-used.
7. **Not carbon neutral if unsustainable**, whereas geothermal has very low CO₂ emission.

#### Summary table
| Aspect | Biomass | Geothermal |
|---|---|---|
| Availability | Everywhere | Site-specific |
| Fuel cost | Collection cost | Free |
| Supply | Seasonal | Continuous |
| Capital cost | Low | Very high |
| Technology | Simple | Complex (drilling) |
| Pollution | Smoke, particulates | Low (H₂S, minerals) |
| Use in Nepal | Main energy source | Hot springs; bathing, tourism only |

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. Which is an advantage of biomass over geothermal?
   A. Biomass is available everywhere while geothermal is site-specific
   B. Biomass has higher energy density
   C. Biomass is continuous all year
   D. Biomass has free fuel
   Answer: A. Geothermal is limited to hot-spring or volcanic regions. (Key point: Availability)

2. Biomass disadvantage versus geothermal steam?
   A. Very high capital cost
   B. Low energy density, bulky to transport
   C. Needs deep drilling
   D. Very high efficiency
   Answer: B. Geothermal steam is a concentrated source; biomass needs large volumes. (Key point: Energy density)

3. Which describes supply?
   A. Geothermal is seasonal, biomass continuous
   B. Both seasonal
   C. Biomass can be seasonal while geothermal gives steady base load (capacity factor about 90%)
   D. Both continuous
   Answer: C. Crop residues are seasonal; geothermal is continuous. (Key point: Supply continuity)

4. Which is true about technology and capital?
   A. Geothermal is simple and low cost
   B. Both need drilling
   C. Biomass needs deep drilling
   D. Biomass technology is simple and low cost; geothermal needs drilling and very high capital
   Answer: D. Stoves and digesters can be built locally; geothermal needs exploration and drilling. (Key point: Technology and cost)

## Related in Power Plant Design

- [Bio-energy with an example](https://www.bctengineer.com/question.md?key=semester_8%2Fpower_plant_design%3Abio-energy-example) — Power Plant Design, chapter 1
- [Thermal, geothermal and nuclear plants compared](https://www.bctengineer.com/question.md?key=semester_8%2Fpower_plant_design%3Athermal-geothermal-nuclear) — Power Plant Design, chapter 1, asked 7×
- [Thermal, geothermal and PV plants compared](https://www.bctengineer.com/question.md?key=semester_8%2Fpower_plant_design%3Athermal-geothermal-pv) — Power Plant Design, chapter 1, asked 7×
- [Geothermal energy uses and plant types in Nepal](https://www.bctengineer.com/question.md?key=semester_8%2Fpower_plant_design%3Ageothermal-use-nepal) — Power Plant Design, chapter 1
- [Biomass and the carbon neutral cycle](https://www.bctengineer.com/question.md?key=semester_8%2Fpower_plant_design%3Abiomass-carbon-neutral-cycle) — Power Plant Design, chapter 1
- [Conventional, non-conventional sources and biomass](https://www.bctengineer.com/question.md?key=semester_8%2Fpower_plant_design%3Aenergy-sources-biomass) — Power Plant Design, chapter 1

## Related in other subjects

- [Synthetic fuel from biomass, bio fuel cells](https://www.bctengineer.com/question.md?key=semester_7%2Fenergy_environment_and_society%3Asynthetic-fuel-biofuel-cell) — Energy Environment and Society, chapter 3
- [Bio-chemical conversion of biomass](https://www.bctengineer.com/question.md?key=semester_7%2Fenergy_environment_and_society%3Abiochemical-conversion-biomass) — Energy Environment and Society, chapter 3
- [Geothermal energy and applications](https://www.bctengineer.com/question.md?key=semester_7%2Fenergy_environment_and_society%3Ageothermal-energy-application) — Energy Environment and Society, chapter 3
- [Wind and geothermal advantages in Nepal](https://www.bctengineer.com/question.md?key=semester_7%2Fenergy_environment_and_society%3Awind-geothermal-advantages-nepal) — Energy Environment and Society, chapter 3