Q: You talk about islanding certain loads for demand charge reduction. In residential storage there’s an energy meter linked to the ESS that monitors the whole-building consumption so that the battery can provide energy when needed. Are commercial ESS systems not like that? Seems like that would be less expensive than islanding loads.
A: For a commercial system, one could island some loads and serve them primarily with a battery based inverter system. However, commercial system owners are not likely to rewire their establishments to do so, as they have many more loads, and potentially they have them spread over several subpanels scattered throughout the facility. Currently, we are not seeing many suppliers catering to this market, and providing solutions that can help here. We hope to see more solutions soon, with computerized sub panels that can monitor loads, shed non-essential loads if needed, and send signals to a battery based inverter or generator to inject power when needed to offset demand spikes.