Biomass represents all organic matter on earth which has stored solar energy in it, by natural process of Photosynthesis over its lifetime, and is available on a renewable basis. There are not any fixed definitions for biomass however here are some:

  1. Plants, trees and organic matter that are created by the process of photosynthesis.
  2. A solar energy stored in an organic matter.
  3. A photo chemical approach in organic matters to harness solar energy by means of photosynthesis process.


This means, all plant-life trees including agricultural plants, bush grass and aquatic plants on earth are falls under the category of biomass.

Main Sources of Biomass

  1. Forest and its Residues (Wood, twigs, branches, Sawdust etc.)
  2. Agricultural Residues (Rice husk, Straws, jutes, Cotton Shell, Coconut Oil etc.
  3. Aquatic and Marine Biomass (Aquatic plants, Marine Algae, Aquatic weeds
  4. Waste (Animal waste, Industrial waste, Muuicipality solid waste, Sewge Sludge, etc.)

Energy from Biomass

Solar energy is the source or origin of Biomass energy. The energy received from sun that is being stored/ accumulated as organic compound throughout the plant life are the biomass energy.

Solar energy --> Photosynthesis --> Biomass Energy generation

Photosynthesis is the process by which sun energy is converted into organic compound. Conversion of Solar energy into an organic compound can be illustrated by chemical formula as below:

H2O + CO2 + Solar energy --> CH2O + O2

The CH2O, is an organic compound which is the basic molecules for forming carbohydrate (sugar, starch, cellulose etc.). Carbohydrate is stable at low temperature, but when it is heated at high temperature its molecules react with oxygen and breakdown into carbon-dioxide and water vapour releasing some amount of heat energy (equal to 112 Kcal/ mole). This can be illustrated as:

CH2O + O2 --> CO2 + H2O + Heat energy.

This is the basic process of converting biomass energy into useful heat energy.

Importance of Biomass

  1. Widely available and more evenly distributed than any other fossil fuel.
  2. Can be converter into modern form of energy (solid liquid and gaseous). So they can contribute a great proportion of annual energy requirement.
  3. By products can be fully recycled.
  4. Helps to reduce pollution. Using waste product for fuel reduces the volume of waste that otherwise would be buried in landfills.
  5. In developing countries like Nepal it can provide a basis for rural development.
  6. Defrosted and degraded lands might be restored with the growing use of biomass as energy.


  1. It might be costly where the land price is very high.
  2. High moisture (50%-95%) makes collection and transportation of biomass costly.
  3. The gaseous or liquid fuel produced from biomass is not readily suitable for storage and transportation and further processing is required which involve major cost.
  4. Availability of biomass, its type and quantity differ place to place and depend on climatic condition as well. A good planning must be done for best utilized the biomass energy resource.
  5. Only a very small fraction (order of about 0.1%) of solar radiation can be converted into biomass by photosynthesis.

Biomass in Nepal
Late Father B. R. Saubolle put the first biogas plant in Nepal at St. Xaviers school, Godavari in 1955 [3]. Several organization including Department of Agriculture (DOA) and Consulting Services (DCS) of Nepal, the United Mission to Nepal and the Khadi and the Village industries Commission of India became involved in promoting the biogas technology.

Almost two decades after the first biogas was installed in Nepal, His Majesty’s Government of Nepal (now called Nepal Government) launched the first official biogas program in 1974. As a result of interest free loan that was provided by Agricultural Development Bank of Nepal, a total of 250 family size plants were constructed during the year.

The Biogas and Agricultural Equipment Pvt. Ltd., a state owned entity, established in 1977 by the government was charged with the responsibility of advancing the development and promoting wide scale dissemination of the biogas technology in Nepal. The Biogas and Agricultural Equipment Pvt. Ltd is also widely known as Gobar Gas Company.

Achievements so Far [5]
With the help of different international organizations, NGOs, biogas companies and Government offices,

  1. 140,457 biogas plants have been installed throughout the country by the 15th July 2005.
  2. 57private Biogas Companies have been strengthened.
  3. 14 Biogas appliances manufacturing workshops are developed.
  4. High level quality standards and quality control system is developed.
  5. 97% of constructed plants are in operation.
  6. 88,000 toilets are constructed and connected with biogas plants.
  7. 80% of bio-slurry is utilized as an organic compost fertilizer.
  8. Biogas programme is being developed as a first CDM project in Nepal.
  9. ISO 9001-2000 certification holder for its strong quality management system.
  10. 104 micro finance institutes are mobilized on biogas lending.
  11. 860,000 persons are directly benefited.
  12. 11,000 persons got employment.
Though a large number of biogas plants are installed this is very less compared to the total potential biogas plants. On the basis of the number if the cattle in the country it was estimated that the potential for biogas production in Nepal is around 4,356,000 cu. m of gas [3].

Biogas Design
In Nepal, GGC 2047 model is popular [2]. This is a fixed dome design and was designed and developed in Nepal. The features of this model is
     well functioning
     simple and durable
     low maintenance cost
The biogas construction manual can be obtained at
For more information on design contact:
BSP – Nepal, Tel: +977 1 5529840/5524665,

Figure 1.  General Biogas Plant Design Layout [2]

Environmental Issue
It is assumed that the installation of 1000, 000 bio gas plants in Nepal will save
     170, 000 metric tons of fuel wood,
     72, 000 tons of agricultural residues
     40, 000 tones of dung and
     4.5 million liters of kerosene and thus resulting in positive carbon dioxide balance in terms of both carbon balance and carbon absorption. This will also help in implementing the clean development mechanism in biogas sector in Nepal. In recent years it has also indicated potentials as a source of national income through carbon trading under the Clean Development Mechanism (CDM).

Financial subsidy and the banks loan at minimal interest rate, provided to the plant owner are the successful components that help in the promotion of biogas in rural Nepal. Currently three commercial banks, listed below, have been involved in biogas financing.

  1. Agriculture Development Bank of Nepal (ADB/N),
  2. Nepal Bank Limited (NBL) and
  3. Rastriya Banijya Bank (RBB)

Figure 2. Institutional Setup of BSP Nepal [1]

Subsidy Mechanism
Biogas plants are given subsidy under biogas program in order to benefit the rural households.  With joint funding of HMG/N, KfW and SNV/Nepal the subsidy is being provided under Biogas support program.  This subsidy is valid for the biogas plant less than 10 cu.m

Table 1: Subsidy Chart [4]
  Subsidy Allowed Subsidy Allowed Subsidy Allowed
Name of Districts/places
1. All districts of Terai as decided by his Majesty’s Government.
2. All municipalities of Kathmandu valley
3. Hetauda municipality
4. Dang and Chitwan districts.
1. VDCs out of Kathmandu Valley municipalities.
2. Hilly districts like sindhuli, Udaypur, Makawanpur excluding hetauda municipality as decided by HMG.
1. Excluding Dang and Chitwan and the districts connected by road by the end 2053/4/1. The districts are: Terahthum, Sankhuwasabha, Bhojpur, Solukhumbu, Okhaldhunga, Khotang, Ramechhap, Manang, Mustang, Myagdi, Rukum, Dailekh, Jajarkot, Rolpa, Jumla, Kalikot, Mugu, Humla, Bajura, Bhajang, Accham, Darchula.
Plant Size
( in cu.m )
Subsidy per Plant
(in x1000)

Uses Biogas can be used for various purposes like:
     machine operation
However biogas is mainly used fro cooking in Nepal and also for lighting in some places. Using biogas for cooking has helped in reducing the fuel wood in large extent thus conserving the forest and also helped reduce expenses on imported fuel by replacing the kerosene.


Social Implications

  1. Reduced indoor pollution
  2. Livelihood enhancement
  3. income generation opportunities
  4. potential national income source through carbon trading

Organizations involved in biomass research implementation research and development
Alternative Energy Promotion Center
Biogas Sector Partnership _ Nepal
Netherland Development Organization SNV

An old woman cooking on biogas in rural Nepal. [6]

A gal manages her biogas plant [7]


[1], June 22, 2006
[2], July 3, 2006
[3], June 22, 2006
[4], June 23, 2006
[5] , June 22, 2006
[6], June 22, 2006
[7], July 14, 2006, July 3, 2006