Life Cycle Assessment (LCA): Global Warming Impact of Biomass Sawdust from Gamal (Gliricidia sepium) Production in Indonesia

Abstract

Biomass is one of the most promising alternative energy sources. Renewable energy from biomass is gene-rated through cultivation and processing. Conducting a life cycle assessment (LCA) is essential to quantify the overall emissions associated with biomass energy. In Indonesia, biomass cofiring technology represents a viable option for achieving renewable energy mix targets due to its rapid implementation and low cost. The country aims to utilize 10 million tonnes of biomass annually for cofiring. This study estimates emissions from biomass used as a cofiring feedstock, derived from an integrated Gamal energy plantation forest (HTE). LCA calculations performed using SimaPro software indicate that CO2 emissions from biomass sawdust with a particle size of 2.5 3 mm amount to 222 g CO2 eq/kWh and 298 g CO2 eq/kg. In comparison, emissions from coal-based energy are three to four times higher. To accelerate a just energy transition, the Indonesian government has introduced a carbon tax of 30,000 IDR per tonne of CO2 eq in the power generation sector. However, this rate is insufficient to effectively incentivize power plants to transition from coal to biomass cofiring. A sensitivity analysis suggests that a more effective carbon tax would be at least 6.5 USD per tonne of CO2 eq.