Microgrid

A microgrid is a premises wiring system that combines generation, energy storage and loads, and it can both separate from the primary source and run in parallel with it. The NEC allows a microgrid to disconnect from the primary source and run as a separate system. When it reconnects, it must have the equipment needed for a synchronous transition. A microgrid interconnect device handles separating from the primary source and reconnecting to it, and a microgrid controller usually provides the logic that starts these transitions. One example is the Enphase IQ Meter Collar, a meter socket adapter that has an integrated interconnect device and energy meter. Tesla describes two microgrid designs. The off-grid version is an isolated grid. The grid-connected version can island. Both use a Tesla battery together with approved solar, generator or wind assets. A typical off-grid layout includes a battery meter, battery, solar meter, solar inverter, loads, generator, wind turbine and grounding transformer. Off-grid control functions include black start, state of energy management, a spinning reserve controller and operator limits for generation assets. The grid-connected version also offers on-grid functions such as Volt-VAr, Volt-Watt and frequency droop. Grid-following string inverters such as the Solectria PVI 25TL-480-R and the PVI 25TL-208 to 60TL models are not intended for microgrid or off-grid use.

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• sentence 5: support check: partial - The component list is in the figure legend, but 'typical' is not stated and the passage says assets are 'and/or', so not all are necessarily included. -->