Yogyakarta- Energy is one of important factors in each country's development in the world. Ownership and control of energy can guarantee the economy to roll. The easier access to get energy, the more increasing economic activities and development. Therefore, energy use is the measurement of prosperity of a nation. A more developed and prosperous country will consume higher amount of energy per capita. Data showed that countries which have high Gross Domestic Product (GDP) use high electric energy, too. Compared to three developed countries in East Asia, energy consumption of Indonesian people is as much as 0.55 TOE (Ton of Oil of Equivalent), whereas Japan is 4.04 TOE, South Korea 4.27 TOE and Singapore is 5.27 TOE.
Further, Harwin said that biomass cannot be compared with coal. Coal is the real fuel, whereas biomass is rather difficult to be called as fuel though it can get combusted due to its combustibilty. No wonder if the density of both fuels is very different because biomass is formed only in a matter of years' period while coal is formed after million years.
Biomass is lacking in its low energy density. If biomass is used as main fuel (single) in a big scale electric power station, input volumetric rate which is needed is certainly very big. “On the other hand, the use of biomass waste in local electric power station needs high specific investment cost, many operators and has low thermal efficiency,” he said.
By considering the various potentials and obstacles, Harwin offered several solutions. The solution is co-firing or co-combustion (collective combustion between coal and biomass in burning room of existing big scale Steam Energy Power Station. It is better if the coal power station is near the biomass waste resource (less than 50 km- 80 km) so the transportation cost of biomass is not too high.
Co-firing is more useful for low quality coal which is abundant in Indonesia. Besides, it is more environment-friendly. Meanwhile, co-combustion is proven more economical for power station. Besides, combustion system in Steam Energy Power Station in Indonesia is generally appropriate for co-firing with biomass. “Other alternative which is included in the co-combustion category is bio-briquette in which biomass is mixed with coal, pressed to be made briquette,” the lecturer of Mechanical and Industrial Engineering Department finished his explanation.