The PLN (Indonesia State Owned Electricity Company) cofiring program, which is mixing biomass fuel with coal in coal power plants, will clearly encourage the use of biomass as an energy source. Cofiring is the easiest and cheapest way for coal power plants to start entering or gradually using environmentally friendly renewable energy. Emissions are also getting better as the use of biomass fuels increases, such as because the sulfur content is very low, there is little ash instead of hazardous waste, and fly ash is very small. The amount of added biomass, for example, starts from 1% which is then gradually increased and even finally it can be 100% biomass or renewable energy. In 2020 the cofiring program has been initiated with a target of 37 coal power plants and by the end of 2020 it is reported that it has been implemented for 20 coal powerplants. While in total there are 114 coal power plants units owned by PLN that have the potential for cofiring, spread across 52 locations with a total capacity of 18,154 megawatts (MW) with a target of completion in 2024. Consisting of 13 coal power plant locations in Sumatra, 16 coal power plant locations in Java, Kalimantan (10 locations), Bali and Nusa Tenggara (4 coal power plant units), Sulawesi (6 locations) and Maluku and Papua (3 coal power plant locations). Meanwhile, the cofiring ratio ranges from 1-5% biomass with an estimated biomass requirement of 9-12 million tons per year. Technically, with the 1-5% cofiring ratio, the PLTU also does not need to modify its equipment, so that it can be used immediately after the biomass fuel meets the required specifications.
When detailed about the type of technology used by coal power plants in Indonesia today, there are three types of coal power plant, namely, 43 types of PC (Pulverized Coal) with a total capacity of 15,620 MW requiring a mixture of 5% biomass or the equivalent of 10,207.20 tons per day, 38 types of CFB ( Circulating Fluidized Bed) a total capacity of 2,435 MW requires 5% biomass or the equivalent of 2,175.60 tons per day. Meanwhile, 23 types of stoker with a capacity of 220 MW use 100% biomass or the equivalent of 5.088 tons per day. In the short term, the type of biomass used is waste based, while in the long term it is from energy plantations. The Ministry of Environment and Forestry has also allocated a land area of around 12.7 million hectares for the provision of forest land to jointly support the coal power plants biomass supply program. Ex-mining lands covering an area of about 8 million hectares should also be reclaimed using this energy plantation. Even PLN has also signed a memorandum of understanding or a Memorandum of Understanding (MoU) with PTPN III Holding (Persero) and Perum Perhutani. In this case, PLN is the owner of the PLTU, while Perhutani has the resources of industrial forest areas both in Java and outside Java that can be developed as energy plantations. Likewise with PTPN III which has land for the development of energy plantations, read here for more details.
To fulfill the need for biomass as an energy source, energy plantations must be increasingly encouraged. The production of biomass fuels from energy plantations takes longer than processing forestry and agricultural wastes such as felled wood waste, sawdust, wood waste from the wood processing industry, palm oil empty fruit bunches, coconut husks, rice husks, and so on. . The route or option with energy plantations was chosen because in addition to ensuring the quality and quantity of biomass fuel it also optimizes land use, including being integrated with livestock and can be harvested multiple times (coppice) without having to replant for the next harvest. In fact, because energy plantation plants use legumes such as gliricidia and calliandra, which the roots can fix nitrogen from the atmosphere, soil fertility also increases. However, more and more efforts are needed for the energy plantation route because it takes at least 2 years for these crops to be harvested and before that it also needs to prepare the soil and plant the trees.
As previously stated, the choice of production for the type of fuel from energy plantations is influenced by several factors, such as the distance between energy plantations and industrial users, production capacity, industrial needs according to combustion technology and investment cost. If the industrial location or power plant is close to each other, even in the energy plantation area, it is sufficient only to make wood chips from the energy plantation. This is because transportation costs are cheap. Meanwhile, if the location is far enough, the wood should be processed into wood pellets or wood briquette. Wood pellets are indeed much more popular than wood briquettes, although technically wood briquette production is easier and production costs are cheaper. In addition, technically, the density of wood briquette can also be higher than wood pellets. This becomes interesting if a producer is interested in wood briquette production as a product diversification and biomass densification technology.
For sustainability, energy plantations will also be better than the use of agricultural and forestry wastes or the timber industry as mentioned above. This is because the plantation is designed and made specifically for the purpose of wood as an energy source. This also makes the volume of wood production more certain than relying on the volume of waste, whose availability depends on the main product. Energy plantations and the following livestock businesses are likely to become an exciting new trend and hopefully the momentum will not be anymore.