Interconnection Standards
State Policy Resources
Interconnection Documents and Resources
- The Interconnection Standards Fact Sheet outlines how and why states could implement standard interconnection rules to encourage DG technologies. Download a PDF version (4 pp, 135K) to print and share.
- The Survey of Interconnection Rules (PDF) (70 pp, 392K) highlights the critical issues for interconnection standards and provides short descriptions of state interconnection provisions.
- EPA Clean Energy-Environment Guide to Action, Section 5.4 (PDF) (16 pp, 1.4 MB) offers additional detailed information for implementing standard interconnection rules as part of a state clean energy policy.
- Interconnection Benefits
- February 2008 Research
- Research Approach
- Assessment
- State Examples
- Additional Resources
Note: Many links on this page go to non-EPA Web sites. Please read the EPA Disclaimer.
Standard interconnection rules establish clear and uniform processes and technical requirements that apply to utilities within a state. These rules reduce uncertainty and prevent time delays that clean distributed generation (DG) systems can encounter when obtaining approval for electric grid connection.
States that modified interconnection rules focusing only on net-metered systems have found these changes were insufficient to encourage clean DG. This is largely due to the small capacity limits on net-metered systems, which limits larger DG systems from accessing the grid for backup power.
Presentations from the June 26, 2008 webinar on "Interconnection Standards: Best Practices for Effective Rules and Standards" presentations are also available.
Interconnection Benefits
Standardized interconnection requirements support the development of clean DG by providing clear and reasonable rules for connecting clean energy systems to the electric utility grid. This helps states achieve success with other clean energy initiatives.
February 2008 Research
As of February 2008, 31 states had adopted standard interconnection rules for DG, and 11 additional states are in the process of developing rules.
In February 2008, EPA completed a research project to assess existing state interconnection rules for their DG friendliness. The maps below show which states have interconnection rules in place, and which of the existing interconnection rules are friendly to DG.
State Interconnection Standards
Policy in place:
AR, AZ, CA, CO, CT, DE, FL, GA, HI, IN, MA, MI, MO, MN, NH, NJ, NM, NY, NV, NC, OH, OR, PA, SC, TX, UT, VT, VA, WA, WI, WY
Action is pending/possible:
AK, DC, IA, ID, IL, KS, MD, SD, TN, WV
Some elements of policy are in place:
KY
Policy not in place:
AL, LA, ME, MS, MT, NE, ND, OK, RI
Established State Interconnection Standards: Assessment for DG Friendliness
Favorable Interconnection Standards:
CA, CT, DE, IN, MA, MI, NH, NJ, NY, NV, OH, OR, PA, VT, WA
Unfavorable Interconnection Standards:
AR, FL, GA, KY, LA
Neutral Interconnection Standards:
AZ, CO, HI, MN, MO, NC, SC, TX, UT, VA, WI, WY
No policy in place:
AL, AK, DC, ID, IA, IL, KS, ME, MD, MS, MT, NE, NM, ND, OK, RI, SD, TN, WV
Research Approach
EPA's research project set out to assess interconnection rules based on the following items:
- Standard interconnection forms
- Simplified procedure for smaller systems (typically 10 kW or less)
- Timeline for application approval
- System size limits
- Insurance requirements
- Technical requirements
Assessment
EPA assessed the DG friendliness of existing interconnection rules through the following criteria:
- Favorable: Indicates that there is a well-defined interconnection policy in place that has at least one or more beneficial attributes:
- Standard forms
- A reasonable timeline for application approval
- Low or no additional insurance requirements
- Allows for >10 kW residential and >100 kW commercial D units to interconnect
- May have additional positive attributes
- Neutral: Indicates that there is an interconnection policy, but overall the policy cannot be considered either beneficial or detrimental to DG.
- Unfavorable: Indicates that the interconnection policy may be available, but has unfavorable requirements such as:
- Only allowing small units to interconnect (<10 kW residential and <100 kW commercial)
- Having high liability insurance requirements
- Requiring owners/operators to pay large interconnect study fees
- May have other burdensome requirements
EPA assessed 50 states and the District of Columbia and found the following results:
- 55% have standard interconnection forms
- 29% have a simplified procedure for smaller systems
- 35% have a set timeline for application approval
- 45% have larger system size limits (over 10 kW for residential and over 100 kW for commercial systems)
State Examples
- The Oregon Public Utility Commission adopted interconnection standards in July 2007 after a nearly year-long stakeholder process. This rule allows non-residential IOU customers with systems up to 2 MW to interconnect. They started with the Mid-Atlantic Distributed Resources Initiative (MADRI) model rule and made several improvements:
- Added “field certification” concept
- Non-inverter-based Level 2 fast tracking up to 2 MW
- Increases Level 1 to 25 kW
- In June 2002, the Massachusetts Department of Telecommunications and Energy (DTE) initiated a rulemaking to develop interconnection standards for DG. The policymakers within the DTE established a DG Collaborative to engage stakeholders (including utilities, DG developers, customers, and public interest organizations) to jointly develop a Model Interconnection Tariff, which established a clear, transparent, and standard process for DG interconnection applications.
- New York was one of the first states to issue standard interconnection requirements for DG systems. Enacted in December 1999, the initial requirements were limited to DG systems rated up to 300 kilowatts (kW) connected to radial distribution systems. In September 2005, New York modified these interconnection requirements to include interconnection to radial and secondary network distribution systems for DG with capacities up to 2 megawatts (MW).
- In November 1999, the Texas Public Utility Commission adopted substantive rules that apply to interconnecting generation facilities of 10 MW or less to distribution-level voltages at the point of common coupling. This ruling applies to both radial and secondary network systems. The rules require that Texas utilities evaluate applications based on pre-specified screening criteria, including equipment size and the relative size of the DG system to feeder load. These rules are intended to streamline the interconnection process for applicants. Texas's interconnection standards can be found in the Distributed Generation Interconnection Manual (PDF) (114 pp, 516K).
Additional Resources
- Interconnection Standards Fact Sheet, also available in PDF (4 pp, 135K), outlines how and why states could implement standard interconnection rules to encourage DG technologies.
- EPA Clean Energy-Environment Guide to Action, Section 5.4 (PDF) (16 pp, 1.4 MB) offers additional detailed information for implementing standard interconnection rules as part of a state clean energy policy.
- The Regulatory Assistance Project (RAP) prepared a Survey of Interconnection Rules (PDF) (70 pp, 392K) for the June 2006 Oregon Public Service Commission Workshop on Interconnection of Distributed Generation. This paper addresses the regulatory context for interconnection of smaller scale DG. The paper is intended to highlight critical issues in interconnection and to provide a condensed recitation of the provisions for interconnection that are contained in existing interconnection rules and in selected draft and model interconnection rules.
- EPA's State Clean Energy Program Activities outlines state and local government programs and policies geared toward integrating energy efficiency, renewable energy, and clean DG for businesses and residents.
- Increasing the Use of Clean Energy Supply in Florida: Removing Key Barriers and Creating New Opportunities (PDF) (36 pp, 503K) presentation and accompanying speech (WMA, 3hrs, 37min, About WMA) were created by Ted Bronson of Power Equipment Associates to outline what steps Florida could take to improve clean energy use in the state. The presentation and speech include state-specific examples of policies favorable to CHP: utility rates, renewable portfolio standards, and interconnection standards.
- The Mid-Atlantic Distributed Resources Initiative (MADRI) has developed Model Small Generator Interconnection Procedures (PDF) (129 pp, 887K).
- The National Association of Regulatory Utility Commissioners (NARUC) has developed Model Interconnection Procedures and Agreement for Small Distributed Generation Resources (PDF) (56 pp, 614K).
- The Interstate Renewable Energy Council (IREC) has prepared a model interconnection rule and guide to connecting DG to the grid.
- The U.S. Combined Heat & Power Association (USCHPA) brings together diverse market interests to promote the growth of clean, efficient CHP in the United States. As a result, it has been a stakeholder in states that have developed standard interconnection rules.
If you would like additional assistance, please contact Katrina Pielli (pielli.katrina@epa.gov).