Effective Methods for Calculating Carbon Emission Reductions

Introduction to the Global Challenge

Carbon emissions within the electricity sector are primarily driven by power generation from fossil fuels, including coal, oil, and natural gas. These activities release carbon dioxide (CO₂) into the atmosphere, serving as a significant contributor to global greenhouse gas emissions and climate change.

To combat this, Mini Hydropower Plants (MHPP), particularly run-of-river systems, offer a sustainable alternative. These plants generate electricity using the natural flow of rivers without the need for fuel combustion. By substituting electricity that would otherwise be generated from fossil-fuel sources, MHPPs play a crucial role in reducing carbon emissions and supporting the transition to clean energy

Objectives of Carbon Calculation

Calculating carbon emissions for MHPPs serves several vital purposes for PT Bumiyasa Indonesia Energi (PT BIE):

• Environmental Impact: Quantifying the environmental benefits of renewable electricity generation.

• Climate Mitigation: Identifying specific contributions to emission reductions by replacing fossil-based power in the grid.

• Corporate Responsibility: Supporting ESG (Environmental, Social, and Governance) and sustainability reporting. This data demonstrates a commitment to environmental responsibility and highlights efforts in climate change mitigation.

Methodology of Calculation

The process of determining emission reductions involves three primary steps:

1. Baseline Emission Calculation (EBy)

The baseline represents the emissions that would have occurred in the absence of the mitigation project.

EBy = PLy x FEGY

• PLy: The net electrical energy delivered to the interconnected power system (MWh).

• FEGY: The GHG Emission Factor for the electricity system (tCO₂/MWh).

2. Mitigation Action Emissions (EPy)

Because MHPPs utilize renewable water flow without combustion, the emissions produced by the mitigation action itself are considered zero:

EPy = 0

3. Total Emissions Reduction (PEy)

The final reduction is calculated by subtracting the mitigation emissions from the baseline:

PEy = EBy - EPy

Understanding Emission Factors (FEGY)

The emission factor is a critical variable sourced from the Ministry of Energy and Mineral Resources (ESDM). There are two primary approaches to determining this factor:

• CM Ex-Ante: Determined before project implementation using historical grid data. This value remains fixed, making it ideal for project planning and initial estimations.

• CM Ex-Post: Calculated after project operation using actual, real-time data from the electricity system. This value may fluctuate as it reflects the current generation mix and operating conditions of the grid.

Regional Emission Factor Examples

Grid Name	Province	OM (ton CO2/MWh)	BM (ton CO2/MWh)	Emission Factor (ton CO2/MWh)
				CM Ex=Post		CM Ex-Ante
				OM=0.5 BM=0.5	OM=0.75 BM=0.25	OM=0.5 BM=0.5	OM=0.75 BM=0.25
Jamali	West Java	0.8	0.94	0.87	0.84	0.87	0.83
	Central Java
Sumatera	Sumatera Selatan	0.77	1.12	0.94	0.86	0.93	0.84
Ampana	Central Sulawesi	0.61	N/A	N/A	N/A	N/A	N/A

Source : gatrik.esdm.go.id