Biomass compared with geothermal energy

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