Bio Energy

Biogas

Biogas is a renewable and environmentally friendly form of energy produced through the anaerobic digestion of organic materials. Major use of biogas is for thermal (cooking) and electrical(lighting).Biogas plays an important role in the reduction of poverty and mitigating climate change impacts by reducing carbon emission while meeting the need of clean cooking and electrical energy requirements. Biogas has high potential on reducing consumption of fuel wood and LPG consumption, multiple benefits on health/sanitation improvement and positive impacts on the child education improvement. The subsidy is applicable to GGC 2047 Model, the GGC 2047 modified model and the other approved models for various capacities for household/domestic purpose and feasible plants/projects to serve the communities, public institutions, commercial enterprises and municipalities.

Domestic Biogas

Domestic biogas system is being implemented and promoted specially in the rural areas of Nepal. The Manure of domestic animals (oxen and cows, buffaloes etc), human waste/excreta are the primary feeding material/source for this biogas system. The slurry as a by-product of this system is being more effective on organic and sustainable agricultural productions in Nepal replacing the use of chemical fertilizer which ultimately has saved money and maintained the clean and green surroundings/environment. GoN has been promoting biogas plants of different capacity under this system, such as 2cum, 4cum, 6cum and 8cum plants fall under this category. For those plants, GGC 2047 and modified design of GGC 2047 are being implemented. For domestic biogas subsidy is claimed by construction/installer Company after completion of plant construction.

Urban Domestic Biogas Plant

The urban domestic biogas plant, named as Sahari Gharelu Biogas Plant (SGBP) for easier local understanding, is a new and unique technological concept in Nepal. It is based on the principles of a floating drum biogas plant. After long research and experiment, GoN introduced it for the mass dissemination. Currently, plants of 1 cubic meter are introduced, but the plants up to 4 cu m (1-4 cu m) capacity fall in this system and the subsidy for such plants have been accordingly provided. Generally, it is planned to be developed among the urban and semi-urban households of large cities. To manage the organic kitchen waste at the households converting them in to bio-energy is the prime focus of this system. It uses the daily household organic wastes, such as food leftovers, cuttings and clippings, etc to produce biogas for cooking purpose. It is more convenient for maintaining household cleanliness and it also mitigates the inner and outer pollution.
The system was introduced in the fiscal year (FY) (2069/70 B.S. / 2012/13 A.D.), with subsidy for piloting in Kathmandu Valley. With encouraging outputs received in the initial phase, AEPC now aims to introduce this system in the feasible urban areas outside Kathmandu as well.

Large Biogas

The large plants with 12.5 and above cubic meter capacity utilize bio degradable materials such as human waste, solid waste, agriculture residues etc. available in the public institutions such as educational institute, health post, police and army barrack, religious places, senior citizen homes, and orphanage homes. Given the strong social inclusion and enterprise development potential associated with the institutional/community biogas plants, the subsidy for these biogas plants shall be prioritized to productive end uses.

All commercial enterprises such as poultry farms, cattle farms, slaughter houses, small/cottage industries etc. that are owned by private entity are considered to be commercial entities. The enterprises with high volume of organic waste production have a high potential of biogas production. The energy thus produced can either be distributed or self-consumed.

Waste-to-energy is the energy production in the form of electricity or heat from the waste source. The current concept envisions utilizing waste produced in large scale, such as the municipal wastes for energy production through biogas. The concept of Waste to Energy tries to address both the issues of waste management and energy recovery. The subsidy in case of waste to energy plants has been calculated on the basis of the capacity of the installed plant to handle waste in tons of waste per day.

Plants more than 12.5 cum in capacity fall under this category.  It is the advancement in Nepal's biogas technology achieved via the long- term practices on modified GGC 2047 model and the learning from the international technological practices. The phrasal term 'large biogas system' is a catch-hold (umbrella term) which includes the varieties of plants under its specific categorization:

While constructing the community biogas plant more than 12 cubic meter capacity to generate the biogas for the community use within the limit of technical feasibility for distributing the biogas by using the cattle and other organic waste is called community biogas plant.

Large biogas are further categorize in three category on the basis of their plant size:

1. Small (12.5 to 35 cum)
2. Medium (35-100 cum)
3. Large (>100 cum)

Process of Large Biogas Promotion

1. Demand application
2. Approval for feasibility/detailed feasibility study
3. Feasibility study/ detailed feasibility study
4. Approval of feasibility/detailed feasibility study by the Technical Review Committee
5. Agreement for construction/installation
6. Construction and installation
7. Testing and Commissioning and Handover
8. After Sales Service and One Year Guarantee Test

Note: Detailed feasibility study is required for more than 100 cu m capacity 

Rehabilitation of Damaged Projects

Subsidy will be provided for rehabilitation of damaged biogas systems to support the livelihood and daily cooking energy need of rural people, which will at least help them for fulfilling daily cooking solutions. If this need could not be addressed by the GoN or Development partner, people will be compelled to seek for cooking energy options such as firewood from the forest and agricultural residues from their farms, which could cause impacts such as forest degradation and poor health due to household air pollution. On other hand, there could also be heavy reduction on CDM revenue if the damaged plants are not rehabilitated and repaired timely.

Improved Cooking Stoves

Improved cook stoves (ICS) particularly mud-brick ICS with and without chimney is one of the most simple, inexpensive and widely used technologies designed to improve combustion efficiency of biomass and reduce exposure to indoor air pollution.

The benefits of ICS includes: increased thermal efficiency, conservation of forests by reducing fuel wood consumption, reduction in women’s' drudgery, reduction in indoor air pollution and hence smoke-related health disorders, and prevention of fire hazards.

Traditional stoves used in Nepal are simple structures made from clay or having stone or metal tripods. These stoves are very inefficient because they have poor air flow and insulation. As a result, they consume a lot of biomass and produce high levels of indoor air pollution.

ICS was introduced in Nepal in 1950s and continues to be relevant in the present context. AEPC, together with other government, non-government and private organizations, is involved in developing and promoting different types of ICS in Nepal and so far more than 700,000 improved cook stoves have been installed in 63 districts.

ICS Models

Metallic ICS

Introduction

Biomass is the primary fuel of the country. Various types of mud and metallic improved cooking stoves have great scope to replace the traditional cooking stoves that burn fire wood for cooking and heating. Alternative Energy Promotion Centre (AEPC) has been promoting Metallic Improved Cooking Stoves (MICS) since 2009 under Biomass Energy Support Programme. The main objective of this programme is to address dual purpose of simultaneous Cooking as well as Space heating need of people living in remote high hills of Nepal. The target beneficiary of MICS is very remote places, above 1500m, from sea level. The Dissemination has been carried out through the Pre-qualified manufacturer and installer companies with government subsidy. This subsidy is just a quality assurance discount for these beneficiaries that do not cover entire cost. 

MICS Models

In the beginning BESP has promoted three pot hole metallic stoves with water tank, developed through technical support from Kathmandu University. This model was targeted for high hills where ICS is needed for cooking and space heating. Especially Water tank is used to tap waste heat from MICS body. Furthermore, other MICS model is identified and modifications on existing model were done with the learning & feedback provided by users, manufactures, installer and other stakeholders.

At the moment AEPC is promoting two models of MICS as following:

• Three pot hole
• Two pot hole

Institutional ICS

Introduction

Institutional Improved Cooking Stoves are used in hotels, hospitals, hostels, barracks, teashops, restaurants, small scale industries like wool dyeing,daalmoth (snacks) factory etc. IICS can be used for heating water with some modification like joining back-boiler or running metal pipes inside its body. 

BESC with technical assistance from Kathmandu University had finalized three different models of large size IICS which requires different metallic components for reinforcement. Later, the household ICS have also been installed with proper reinforcement at vital parts as well as scaling up the size as per need. These stoves have been widely used in the local teashops of the rural villages. 

Rocket Stoves

Introduction

A rocket stove is an efficient cooking stove using small diameter wood fuel which is burned in a simple high-temperature combustion chamber containing an insulated vertical elbow which ensures complete combustion prior to the flames reaching the cooking surface.

A rocket stove achieves efficient combustion of the fuel at a high temperature by ensuring a good air draft into the fire, controlled use of fuel, complete combustion of volatiles, and efficient use of the resultant heat. It has been used for cooking purposes in many energy poor locales as well as for space and water heating.

BESC has developed a portable mud rocket stoves suitable for house hold use in Terai settlements. The sole purpose of this model is to cater the users who cook inside as well as outside their house.

Benefits:

1. Low cost
2. Fuel efficient
3. Easy to transport
4. Locally buildable
5. Accepted technology, particularly in Terai

Biomass Gasification

Introduction

Biomass gasification is a thermo chemical process where solid biomass such as wood, wood waste and agricultural residue, is converted into combustible gas mixture. The resulting gas, known as “producer gas,” contains CO (15 to 29%), CO2 (5-15%), H2 (5-12%), N2 (50-65%) and small amounts of hydrocarbon gases. The producer gas, which has a calorific value of 1200 to 1500 kcal/m3, can be combusted for thermal energy or used to operate gas turbines or internal combustion engine for mechanical and electrical power.

AEPC is promoting gasifiers under this technology. Basically we have three types of gasifiers

1. Thermal Gasifier cooking stove
2. Institutional Gasifier cooking stove
3. Portable Gasifier cooking stove