Planning for Interconnection and Permitting
Federal energy managers are encouraged to plan for interconnection and permitting early in the process of determining whether to deploy distributed energy resources (DER). This includes electric interconnections for all DER projects connected to the utility and gas line interconnections for projects requiring gas at higher volumes and pressures than the gas distribution system can provide. In addition, you will need to work with various entities to obtain applicable permits.
Some of these activities will require more time, effort, and money than you originally estimated and may pose certain barriers that must be overcome. This section is designed to help you understand the general interconnection and permitting processes and what might be involved.
- The Interconnection Process
- Sample Interconnection Standards
- Typical Equipment Requirements
- Additional Resources
The Interconnection Process
Interconnection requirements vary from state to state and utility to utility. However, the following general process typically applies.
You will file an application with the utility, providing basic information about the proposed project and enclosing a nominal payment for processing and review. You will be informed after a specified period (generally two to three weeks) whether a more involved study is required, what it will include, what it will cost, and approximately how long it will take (typically, about six weeks). This study will then describe the utility system upgrades (if any) that are necessary, what they will cost, and when they can be scheduled. It is then up to you to evaluate the cost in relation to project budget and projected savings and decide if your project is still cost-effective.
This general process is outlined below in six basic steps.
Step 1. Pre-Application Communication
The first step is to contact your local utility and ask about interconnection standards and requirements. You should also be able to establish a single point of contact to discuss any of your interconnection matters.
Step 2. File Interconnection Application
If the result of the pre-application communication indicates that you can move forward with your project, then a formal interconnection application will need to be submitted to the utility.
Step 3. Utility Reviews Application
The utility will decide if interconnection is allowed or if further information or analysis needs to be completed based on the application information you provide on the size, type, and location of your proposed DER project. Depending on your specific project, the process can be more or less complicated. For example, using pre-certified DER technology for your installation or using systems under certain, pre-determined size ranges may expedite the interconnection review and approval process.
Step 4. Interconnection Agreement Signed
Once the interconnection application is approved, you and the utility will complete an interconnection agreement. This agreement can also outline the provisions of any net metering or power purchases resulting from the DER project.
Step 5. Project Construction
In this step, the DER project is built and installed to the specifications outlined by the utility. In addition, the utility completes any new construction or equipment installations, including any metering equipment, necessary to ensure the safe and successful operation of the DER system.
Step 6. Connection, Testing, and Operation
Before the DER system can be operated, it must be tested to verify compliance of the generator and related interconnection equipment with the utility's requirements. Once testing is successfully completed, the DER system is allowed to operate in parallel with the utility's electric grid. A formal letter of acceptance for interconnection of the DER system is generally then issued by the utility.
It is often possible to require your DER contractor to take care of all the necessary interconnection and permitting studies, paperwork, and fees as part of the project contract. Such integrated service providers (ISPs) can simplify the implementation of DER projects and bring needed expertise and experience in navigating the interconnection and permitting processes. The DG Monitor newsletter provided an overview of ISPs, including some examples of such companies located across the country. For more information, see the July/August 2002 (PDF 242 KB) and the March/April 2003 (PDF 206 KB) issues. Download Adobe Reader.
Sample Interconnection Standards
Three "early DER adopter states"–New York, Texas, and California–all developed standardized interconnection requirements. In addition, the National Association of Regulatory Utility Commissioners (NARUC) developed model interconnection standards for states interested in defining their own standardized DER interconnection requirements. Each of these can provide insights into general interconnection practices and requirements. A number of other states are working toward establishing standardized DER interconnection standards. The latest information on state DER regulatory activity can be found on the Department of Energy (DOE) Industrial Distributed Energy Web site.
Additional state-by-state activity, including incentives for renewable energy and DER projects, can be found on the DOE State Energy Information Web site.
Typical Equipment Requirements
To interconnect any DER system to the grid, the utility may specify certain equipment requirements to ensure safe operation of the grid regardless of how the DER system is functioning. Typical requirements include:
- Equipment that prevents power from being fed to the grid when the grid is de-energized (for example, for power line maintenance)
- Manual disconnects that are easily accessible to utility personnel
- Power quality requirements such as limits on the interconnected system's effects on "flicker" and other types of distortion
DER systems may also be required to automatically shut down in the event of electrical failures. To accomplish this, protective schemes at the grid interface may include:
- A synchronizing relay
- Protection against under- and over-voltage
- Protection against under- and over-frequency
- Phase and ground over-current relays
- Ground over-voltage relays
Even more restrictive (and expensive) requirements can include an isolation transformer for the system and liability insurance against worst-case scenarios of damage to utility equipment and harm to utility personnel.
For more information on technical requirements for interconnection, see the DOE Industrial Distributed Energy Web site.
For interconnection requirements and policies specific to renewable energy DER systems, see the DOE Energy Saver Web site.
DOE and the Environmental Protection Agency (EPA) is working to address many of the obstacles to enable more widespread use of combined heat and power (CHP) and distributed energy resources (DER) systems.
FEMP can provide expert, unbiased technical assistance specialized in CHP and DER systems to any Federal agency interested in developing a project. To access these services, contact your FEMP agency customer representative (Excel 28 KB).
For assistance with fuel procurement and utility rate analysis, civilian agencies should consider contacting the General Services Administration (GSA) Energy Center of Expertise. Defense agencies should consider contacting the Defense Energy Support Center.
To locate a qualified DER contractor, agencies should visit the GSA Supply Schedule. The DG Monitor newsletter also provides some examples of DER developers located across the country. For more information, see the July/August 2002 (PDF 242 KB) and the March/April 2003 (PDF 206 KB) issues.