What is an aggregator and what is its role?

An aggregator is a market participant that combines several smaller generators or storage systems into a single portfolio that appears to MAVIR as one unit. It signs a contract with the operator, builds and operates the IEC 60870-5-104 communication link required toward the system operator, handles the accreditation procedure, and in the event of curtailment it controls the actual disconnection and distributes the compensation. Using an aggregator is not always mandatory: a sufficiently large unit — typically a power plant above 5 MW or a larger storage system — can also be accredited directly with MAVIR. The choice is a matter of practical judgment: the aggregator takes over the administration, the technical integration and the responsibility for continuous availability, and in return receives a share of the revenue. For smaller units this is usually worthwhile, because the fixed costs of self-accreditation do not scale down. Before signing the contract, it is worth checking what availability requirement and penalty it contains.