Electric Rule 21:
Distributed Generation Interconnection Rules

 


Electric Rule 21 is a set of rules governing how advanced energy technologies may interconnect with the electric distribution systems of the state’s investor owned utilities – Edison, PG&E, and SDG&E.  These advanced technologies include Energy Storage and Distributed Generation such as roof-top solar.  

In September 2011, the CPUC opened a Rulemaking to review and revise Rule 21 to “ensure that the interconnection process is timely, non-discriminatory, cost-effective, and transparent.”  

 

Reform to Rule 21 have been covered in various proceedings:

  

CPUC Decision on Rule 21 Reforms

In September 2012, the CPUC issued a Decision approving the first set of reforms to Rule 21 establishing a process to accommodate the interconnection of exporting generating facilities. Under this reform all requests made to the utilities to interconnect to their distribution systems would be designated to one of two major study tracks to be performed by the utilities:    

  • The Fast Track:  A streamlined interconnection review process for which Net Energy Metering, non-export facilities (not exporting energy to the distribution system), and some exporting facilities are eligible.  To be eligible for the Fast Track, an applicant must meet a series of requirements.  
  • The Detailed Study: A more consuming interconnection review process should the applicant not meet the requirements set forth in the Fast Track.   

 

CPUC Decision on Distribution Group Study Process 

In April 2014, the CPUC issued a Decision directing the utilities to incorporate a Distribution Group Study Process into Rule 21. This Distribution Group Study Process conducted by the utilities, studies interconnection applicants that are determined to impact one another be electrically interdependent and will allocate upgrade costs among them.    

 

 

Interconnection for New Technologies 

In May 2014, the CPUC issued an Amended Ruling directing the utilities to propose specific modifications to Rule 21 to capture new technological advances.  

In July 2014, the CPUC issued a Ruling setting the schedule and requesting comments on two CPUC staff reports:   

 

Cost Certainty

The CPUC opened a Rulemaking to review and revise Rule 21 to “ensure that the interconnection process is timely, non-discriminatory, cost-effective, and transparent.”  

 

Energy Storage

 

 

 

 

CPUC Proceeding Docket

See the Proceeding docket. 

  
 

Other Resources 


Original November 2000 CPUC Decision establishing Rule 21.