California Institute for Energy and Environment (CIEE)

This project is composed of three main components or phases. The purpose of the first phase as described in this report, prepared by Sacramento State University, is to gather and document the existing criteria, rules, and practices used by the Investor Owned Utilities (IOUs) in California for physical interconnection of Distributed Energy Resources (DER). The criteria set by the National Standard IEEE 1547, State of California Public Utilities Commission (CPUC) Rule 21, and the standard practices used by a sample major IOUs will be presented and compared. Adequacy, practicality, and controversial issues associated with implementation of the presently used rules and criteria will be documented and discussed. Suggestions and recommendations for future research and studies in the interest of practicality resolution of the implementation issues and uniformity of interconnections will be identified.

The second phase will support the investigation and verification of specific System Protection related concerns as introduced in this report under “Areas of Concern”, such as Relay Desensitization and selection of proper Transformer connection Types. The concerns will be verified by using System modeling and simulations with industry software.

In third and final phase, the results achieved through modeling and simulations will provide information needed to proceed with safe interconnection of DER through the current standards and rules, while considering relevant technical issues such as those outlined in this report.