## 3.5 Battery Storage

The software provides an EDR credit for a battery storage system that is coupled with a PV array. If specified, the battery storage size must be 6 kWh or larger. For Part 6 compliance this credit has no impact on energy efficiency components. Including a battery storage system allows downsizing the PV system to reach a specific EDR target.

Two control options available are:

Default Control – A simple control strategy that provides a modest EDR credit. With default control, the software assumes that the batteries are charged anytime PV generation (generation) is greater than the house load (load), and conversely, the batteries are discharged when load exceeds generation.

Advanced/Utility or Aggregator-Controlled – A more sophisticated control strategy maximizes the TDV value of stored kWh. With advanced control, the software assumes that the batteries are charged when generation exceeds the load; batteries only discharge during the highest “anticipated” TDV intervals to maximize the value of the stored kWh.

For Part 6 compliance, the proposed design EDR credit is limited to a PV size equal to the site annual kWh. The effect of a larger PV array has a minimal impact on the EDR score. For above code projects, the software allows oversizing the proposed design PV system by a factor of 1.6 for full credit if a battery system of at least 6 kWh is coupled with the PV system.

Software includes an option to allow excess PV generation EDR credit for above code programs. This allows exceeding the 1.6 size limit. When selected, the software allows any size PV with full EDR credit.