2.6 Biomass Energy Systems - V

2.6 Biomass Energy Systems

The Philippines is well endowed with biomass resources generated by extensive agriculture, livestock and forestry industries. The 1997 figures estimated that there are annual reserves of about 131 MMBFOE of these resources. Contributors to this biomass potential are fuelwood, bagasse, coconut residues, ricehull, animal waste and municipal solid waste.

Technologies range from the use of bagasse for cogeneration, rice/coconut husks dryers for crop drying, biomass gasifiers for mechanical and electrical applications, fuelwood and agri-wastes for oven, kiln, furnace, and cookstoves for cooking or heating purposes.

2.6.1 Forestry Resources and Fuelwood

The total land area in the Philippines is estimated at 30 million hectares with 14.1 million hectares considered alienable and disposable and thus available for agriculture. Also, about 15.9 hectares are designated as forest lands. Primary production in the forestry industry in the Philippines is declining following partial and planned total ban on logging in traditional forests. However, new areas of plantation forest are being established. The volume of timber available within commercial forests was estimated at 448 million cubic meters in 1993.

As indicated earlier, fuelwood is a major source of energy particularly in rural areas through the use of cookstoves. However, studies have indicated that 90% of fuelwood used for cooking in the country come from agricultural areas. These are resources considered outside of the context of commercial timber stock, and hence, live outside the framework of traditional forest inventories. Hence, the deforestation in some areas are attributed to commercial logging. However, the government has established a lot of innovative and environmentally responsible programmes for forest management and reforestation.

Aside from being used as household fuels, wood and wood charcoal are also utilized in small-scale commercial activities (bakeries, restaurants, barbecue stalls, tobacco flue-curing, furniture making, among others). The dendrothermal power program in the past was not fully implemented due to various reasons among them were due to management problems, supply or availability of wood and peace and order instability.

2.6.2 Bagasse

Sugarcane residue is used directly in sugar centrals as boiler fuel. There are about 39 operating sugarmills in the country with an average production of 4,600 tons of canes per day. Bagasse roughly contributes to about 10.16 MMBFOE, mostly to the industrial sector or 3.6% to the total energy mix in 1998. A joint report of UNDP-Word Bank has estimated that bagasse can produce as much as 60-90 MW of power that can be exported to the grid.

2.6.3 Ricehull

Total ricehull potential was estimated to be 2.26 million metric tons in 1996. In some areas in the Philippines, this residue is used as fuel in households and rural industries. It is also used as fuel for paddy and brick making. The same UNDP-WB report puts the exportable power of this resource at 40 MW. Several power projects in the past have shown the technical feasibility of the use of ricehusk. These projects faced various problems ranging from technical reasons (wear and tear of parts), supply considerations to management constraints.

Two large-scale ricehull fired power projects are currently being proposed. One is a 35 MW plant in Bulacan Province while the other is a 25-30 MW to be located in the Province of Nueva Ecija. These provinces are among the largest rice producing areas in the Philippines. Both projects have been granted partial accreditation by the DOE.

2.6.4 Coconut Residues (Husks/Shells/Fronds)

These residues are largely utilized as domestic and industrial fuels. Cocoshells are converted into charcoal which is primarily used for cooking, ironing and water heating. They are however primarily processed into activated charcoal for export. As an industrial fuel, it is used for copra drying and in desiccating plants. Cocohusks, on the other hand, are mainly used for copra drying and, to a lesser extent, as fuel for cooking in the households. Cocofronds are used for cooking fuel in household and drying in rural industries.

The total potential of cocoshell and cocohusk in 1997 are 1.79 and 4 million metric tons, respectively. The UNDP-WB study has also estimated this resource to potentially contribute around 20 MW of power to the grid.

2.6.5 Animal Wastes

These wastes generated by poultry and livestock farms could be converted into energy through the biogas technology. This technology is seen more as a pollution mitigation device with an energy generation component rather than a mere energy system. Currently, there are more than 653 operation biogas systems recorded installed in the country ranging from small to large-scale systems.

The technology is already in the commercial stage in the country. The largest user is a private company, Maya Farms, which has developed the technology since the early 70’s. The farm covers 40 hectares of land with a population of about 60,000 heads of hogs and several hundred heads of cattle. The farm is operated in an integrated manner recycling the waste into energy for lighting, refrigeration, running generators and various equipment, breeding piglets, water pumping, running its feedmill as well as for use in its heat scalding tanks and cooking vats. The effluent is dried and mixed with feeds for its livestock or fishes.

There are a total of nine biogas technology manufacturers and suppliers in the country. These manufacturers provide the necessary facility and service to biogas system users. Services include sales and installation of turn-key plants, after-sales monitoring, operation and maintenance services. Concrete digesters are being promoted for backyard to small scale systems because of the availability of local and cheap materials. Environmental concerns are forcing hog farms to adopt a biogas system.

2.6.6 Municipal Solid Wastes

In the Philippine Energy Plan, it is projected by year 2004, municipal solid wastes will start to contribute about 0.44 MMBFOE to the energy mix and shall increase to 0.67 MMBFOE by the year 2008. A JICA funded survey showed that, in Metro Manila alone, wastes are being generated at an average of 0.431 kilogram per capita per day. The same study estimated that Metro Manila produces 5,345 tons of garbage per day (TPD) which includes markets, commercial and other wastes.

With the economic growth and increase in population, it is estimated that wastes generated by Metro Manila may double to 11,000 TPD by the year 2014. At present, there are two sanitary landfill sites and one open dump site, all nearing their design capacity. Target disposal sites are encountering extreme opposition from residents and other sectors. Given the huge volumes and the shortage of disposal sites, the Presidential Task Force on Solid Waste Management, is seriously considering other alternatives to the solid waste management problem including landfill gas generation, composting, recycling and incineration.