Transmission loss adjustment factors (TLAFs)
Transmission loss adjustment factors are how we allocate transmission losses to generators.
What are TLAFs?
When electricity is being transported through networks, not all of the power is transferred. These losses can happen on both the transmission and distribution networks. Higher voltages generally reduce losses.
To ensure that the wholesale market is settled, we allocate the transmission losses to generators. These calculations are called Transmission Loss Adjustment Factors (TLAFs).
We calculate TLAFs alongside EirGrid and the Regulatory Authorities approve them annually.
Who TLAFs apply to
Some generators are responsible for proportionally more transmission losses than others. It depends on their point of connection to the grid. For this reason, TLAFs are site specific.
The following parties that participate in the SEM, known as market participants, are subject to TLAFs:
- Generators connected to the transmission network
- Generators connected to the distribution network
- Interconnectors
- Suppliers (TLAFs for supplier units are set equal to 1.0)
Approved and proposed TLAFs
2024/25 Approved TLAFs
Find previous years in our publications section.