Ancillary Services: An Overview

Ancillary services keep the grid stable between the bulk energy transactions; firm, flexible resources are well placed to supply them.

The services that keep the grid stable

Ancillary services are the supporting products that maintain grid reliability moment to moment: regulation and reserves to balance supply and demand on short timescales, frequency response to arrest disturbances, reactive power to hold voltage, and black-start to recover from a blackout. They are procured separately from energy and are increasingly scarce as spinning plants retire.

The burner (MetroVolt) can supply many of these because it is firm, dispatchable, and inverter-based. Fast, programmable control of active and reactive power lets it provide regulation, reserves, and voltage support; grid-forming control enables frequency response and black-start.

Local delivery is valuable

Several ancillary services are most useful delivered near where they are needed. Voltage support helps the local pocket; black-start and islanding protect the local network. A near-demand burner is therefore well placed to supply the services a growing load center most needs.

Honest framing

Ancillary-service capability follows from the inverter interface and steady-state core, but for MetroVolt it is a design objective. Each service requires the unit to be online and stable, which returns to the availability and plug-regime gates.