Metered subsystems

A metered subsystem is a geographically contiguous system that has been operating as an electric utility within the ISO balancing authority. The metered subsystem balances its own loads and resources within its territory.

Boundaries for a metered subsystem must be encompassed by ISO-certified revenue-quality meters at each interface point with the ISO grid and on all generating units within the boundary, or, if aggregated, each individual resource and participating load internal to the system. Bidding in ancillary services requires special certification and installation of direct telemetry. 

To participate in the ISO markets, a metered subsystem must be a scheduling coordinator or be represented by one. 

To interconnect with the ISO, metered subsystems need to go through the Generator Interconnection process if entering at the transmission level, or the New Resource Implementation process if entering at the distribution level.

Documents required for participation

Establish the contractual agreements early in the process to participate.

Related applications and access

Metered subsystems use a variety of ISO applications to participate in the market.

Related ISO Tariff and BPM

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