Marginal Loss Factors
How we model MLFs, and how they're integrated into the dispatch model
Marginal Loss Factors (MLFs) quantify the impact of electrical losses on energy transfer between a generator or load and the Regional Reference Node (RRN) within the NEM. They are crucial for accurately modelling revenue and dispatch outcomes, especially for battery energy storage systems (BESS).
1. Estimating loss proportions
We trained a regression model to estimate loss proportions for each settlement period. The model incorporates predictors such as:
- Proportion of renewable generation
- Transmission flow proportions
- Temporal factors (e.g., hour of day, day of week, season)
These estimates provide a dynamic view of losses across the network.
2. Calculating volume-weighted losses
By forecasting 5 minute losses and combining this with the import/export profile of the battery, we compute volume-weighted losses. This involves:
- Calculating losses over the year when the battery is importing/exporting
- Aggregating these losses over the financial year
- Calculating the Average Loss Factors (ALFs) when the battery is importing/exporting
- Calculating MLFs by squaring the ALFs (this is the calculation used by AEMO)
This approach aligns with the AEMC’s guidelines on loss factor calculations.
3. Location-based adjustments
We then align our MLF forecast for an asset with the latest published MLF for that asset, to make sure the starting point is correctly aligned. When forecasting for a new asset, we base this MLF on the closest existing asset, and make adjustments to account for a new assets being closer/further from the regional reference node (RRN).
- Historical MLF data: By identifying the nearest historical BESS site to the proposed site, we adjust the MLFs to reflect local network conditions.
- Distance to RRN: We apply a linear regression model that correlates MLFs with the distance from the asset to the RRN.
4. Integration with dispatch modelling
These MLFs are then integrated into our battery dispatch model, meaning the battery's import/export decisions factor in the effect of its import and export MLFs.
Updated 3 months ago