• Battery storage systems that are interconnected behind-the-meter (BTM) can provide services for individual electricity consumers as well as services ‘upstream’ at the distribution- and transmission-levels. ‘Customer-facing’ services can broadly be categorized as (1) Bill savings; (2) Increased PV self-consumption; and (3) Backup power.
  • Bill savings: retail tariff elements determine how a customer is charged for electricity consumed from the grid and consequently determine the extent to which energy storage systems can help to reduce their electricity bills. Flat volumetric tariff elements that charge the same rate for energy consumption from the grid ($/kWh) regardless of when the energy is consumed provide little to no opportunity for energy storage to help customers reduce their bills. Time-of-use energy charges, which charge different rates for consumption during different parts of the day, and demand charge elements, which charge customers based on their maximum instantaneous consumption ($/kW) during a given period, offer opportunities to reduce bills with energy storage by shifting demand to different periods.
  •  Increased PV self-consumption: Production from customer-sited solar PV systems and energy demand may be poorly aligned depending on customer demand patterns. This may mean solar PV energy that exceeds customer demand is either curtailed or exported to the power system, depending on restrictions on the customer’s interconnection agreement. Depending on how solar PV exports are compensated, this may represent a lost financial opportunity for the customer. Energy storage can help customers address the mismatch between their demand and PV generation by storing excess PV energy and discharging to meet demand after PV generation has tapered off.
  •  Backup power: Energy storage, especially if combined with a generating source like solar PV or when interconnecting with multiple distributed energy resources (DER) in a micro-grid setting, can meet the energy needs of customers in the case of grid outages. This can be critical for essential infrastructure by, for example, ensuring power to an emergency shelter or hospital during a storm. Uninterrupted power can also be critical for sensitive industries that would suffer significant consequences from even brief interruptions.