Aggregation Rules & Trading Units
Aggregation rules are algebraic equations which identify the electrical volumes for particular Volume Allocation Units. CVA Metering Systems are complex with many meters and registers and aggregation rules defining how meter readings shall be combined.
BSCP75 ‘Aggregation Rules’ defines the interfaces and timescales for submitting and changing aggregation rules.
A Trading Unit can be one or more Balancing Mechanism (BM) Units. By default, a Trading Unit is a single BM Unit, called a Sole Trading Unit. Being a Trading Unit allows all the BM Units to be treated the same for:
- Transmission Loss multipliers (TLMs);
- Production/Consumption flag;
- Certain BSC costs;
- Residual Cashflow Reallocation Cashflow (RCRC); and
- Balancing Services Use of System (BSUoS) charges.
There are six types of Trading Units:
- Classes 1-3: Generation and demand at the same site
- Class 4: Exempt Export BM Units in the same GSP group
- Class 5: Interconnector BM Units
- Class 6: BM Units that should be treated as Trading Units but don’t meet the conditions of classes 1-5.