---
title: "Conventional, non-conventional sources and biomass"
subject: "Power Plant Design"
chapter: 1
key: "semester_8/power_plant_design:energy-sources-biomass"
source: https://www.bctengineer.com/q/semester_8/power_plant_design/energy-sources-biomass
site: BCT Engineering
---

# Conventional, non-conventional sources and biomass

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

- Asked in: 2073 Magh, 8 marks
- Video: [Energy Resources - Conventional and Non-Conventional](https://www.youtube.com/watch?v=Zgp86PVXXuQ) — Amit Sengupta
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_8/power_plant_design/energy-sources-biomass
- Whole chapter: https://www.bctengineer.com/md/semester_8/power_plant_design/chapter-1

## Question

What do you mean by conventional and non-conventional energy sources? Discuss bio-mass energy suitable examples.

## Short answer

Conventional sources are fossil fuels, large hydro, and traditional biomass; non-conventional include solar, wind, and modern biomass. Biomass energy examples: improved cook stoves save firewood, household biogas from dung provides clean cooking fuel, and bagasse cogeneration in sugar mills produces heat and power from waste.

## Answer

#### Conventional energy sources
Sources that have been in large-scale use for a long time, with mature technology. Most are non-renewable (except hydro and traditional biomass).
- Coal, petroleum, natural gas
- Large hydropower
- Nuclear energy
- Traditional biomass: firewood, cattle dung, crop residue burnt directly

#### Non-conventional energy sources
New or alternative sources, mostly renewable and environment friendly, still developing in technology and cost.
- Solar (PV, thermal)
- Wind
- Small/micro hydro
- Modern biomass: biogas, gasification, bio-fuels, briquettes
- Geothermal, tidal, wave, ocean thermal, hydrogen and fuel cells

| Basis | Conventional | Non-conventional |
|---|---|---|
| Renewability | Mostly exhaustible | Mostly renewable |
| Pollution | High | Low |
| Technology | Mature | Developing |
| Capital cost | Moderate | Often high per kW |
| Running cost | High (fuel) | Low |
| Availability | Concentrated (mines, wells) | Distributed, site-dependent |

#### Biomass energy
**Biomass** is organic matter of plant or animal origin. It stores solar energy by photosynthesis and releases it by burning or conversion. It is renewable if regrowth keeps up with use.

**Conversion routes:**
```text
            +--> Direct combustion --> heat / steam power
 Biomass ---+--> Gasification -----> producer gas -> engine
            +--> Anaerobic digestion -> biogas (CH4)
            +--> Fermentation ------> ethanol
            +--> Pressing/esterify --> bio-diesel
```

**Suitable examples:**
1. **Firewood in improved cooking stoves** – the largest energy use in rural Nepal; improved stoves save about 30–50% of wood and reduce smoke.
2. **Household biogas** – cattle dung digesters supply cooking gas and slurry manure; hundreds of thousands installed in Nepal.
3. **Bagasse cogeneration** – sugar mills burn bagasse to make steam and electricity for the mill.
4. **Rice husk gasifier** – producer gas runs an engine-generator in a rice mill.
5. **Briquettes** – compressed sawdust, rice husk or forest litter (e.g. banmara weed) for clean household fuel.
6. **Bio-ethanol** – from molasses, blended with petrol.
7. **Municipal waste to energy** – biogas from organic waste of cities.

**Advantages:** renewable, carbon neutral, uses wastes, available locally, creates rural jobs.
**Disadvantages:** low energy density, bulky to transport, smoke if burnt in open stoves, can cause deforestation if over-used.

## Check yourself

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

1. Which difference is correct?
   A. Conventional: mostly renewable, low pollution
   B. Non-conventional: mature technology, high pollution
   C. Conventional: mostly exhaustible, mature technology; non-conventional: mostly renewable, developing
   D. No difference
   Answer: C. Conventional sources are long established and mostly exhaustible. (Key point: Conventional vs non-conventional)

2. Anaerobic digestion of biomass gives
   A. Ethanol
   B. Producer gas
   C. Bio-diesel
   D. Biogas (CH4)
   Answer: D. Gasification gives producer gas; fermentation ethanol; digestion biogas. (Key point: Conversion routes)

3. Which is a biomass example?
   A. Bagasse cogeneration in a sugar mill
   B. Solar PV array
   C. Wind turbine
   D. Nuclear reactor
   Answer: A. Bagasse, rice husk gasifiers, biogas and briquettes are biomass examples. (Key point: Suitable examples)

4. A disadvantage of biomass is
   A. High energy density
   B. Low energy density and bulky transport
   C. No smoke ever
   D. Never causes deforestation
   Answer: B. It is bulky and may cause deforestation if over-used. (Key point: Disadvantages)

## Related in Power Plant Design

- [Replacing fossil fuel with non-conventional energy](https://www.bctengineer.com/question.md?key=semester_8%2Fpower_plant_design%3Aenergy-sources-replace-fossil) — Power Plant Design, chapter 1
- [Biomass compared with geothermal energy](https://www.bctengineer.com/question.md?key=semester_8%2Fpower_plant_design%3Abioenergy-vs-geothermal) — Power Plant Design, chapter 1
- [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
- [Energy sources in Nepal and wind scope](https://www.bctengineer.com/question.md?key=semester_8%2Fpower_plant_design%3Aenergy-sources-nepal-wind) — Power Plant Design, chapter 1, asked 2×
- [Energy sources and solar power generation](https://www.bctengineer.com/question.md?key=semester_8%2Fpower_plant_design%3Aenergy-sources-solar-power) — Power Plant Design, chapter 1
- [Why biomass is a renewable source](https://www.bctengineer.com/question.md?key=semester_8%2Fpower_plant_design%3Abiomass-renewable-claim) — Power Plant Design, chapter 1, asked 2×

## Related in other subjects

- [Conventional and non-conventional sources](https://www.bctengineer.com/question.md?key=semester_7%2Fenergy_environment_and_society%3Aconventional-nonconventional-sources) — Energy Environment and Society, chapter 2
- [Conventional vs non-conventional sources with schematic](https://www.bctengineer.com/question.md?key=semester_4%2Fpower_system_analysis_i%3Aconventional-vs-nonconventional-sources-schematic) — Power System Analysis I, chapter 1
- [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