Interconnecting Large Facilities
Qualifying facility more than 10 kilowatts
- PNM will authorize the interconnection of any photovoltaic, or other qualifying renewable resource, generating system rated over 10 kilowatts that complies with the New Mexico Public Regulation Commission rule and with PNM's Interconnection and Safety Standards (see links at right).
- Systems that interconnect by means of an inverter that is UL 1741 compliant meet state and PNM requirements.
- Interconnected systems must comply with all applicable building and electrical codes.
- PNM requires that a utility-accessible, lockable load-break disconnect switch be installed between the output of the inverter and the point of interconnection. This switch is referred to later as the customer generation disconnect switch. This disconnect, which can be operated and controlled by PNM, must provide a verifiable, visible air gap between the inverter and the point of interconnection. Circuit breakers and inverter software modes do not meet the disconnect switch requirement. Be sure to confirm with your installer that opening the customer generation disconnect switch will not cause some of your loads to be without power from PNM.
- For installations where the customer generation disconnect switch is not located adjacent to the PNM metering point, a simple site diagram showing the physical locations of all key components is required. The system one-line and site diagram drawings must identify all major equipment including the inverter, electric service panels, the customer generation disconnect switch and the PNM metering point. These last two items must be clearly labeled on the one-line diagram.
- A list of the protective devices associated with the interface must be submitted to PNM. The list should include, but is not limited to fuses, circuit breakers, protective relays, synchronizing and disconnecting devices. The list should also include the equipment manufacturer and model number.
- A short narrative on the proposed operating procedure for the facility must be submitted to PNM. This procedure should describe the intended step-by-step sequence for operating breakers and disconnects to connect and/or disconnect from PNM's system under normal operating conditions and contingency conditions.
- PNM personnel must verify the proper operation of the interconnection facilities.
- A permanent weatherproof one-line diagram or sketch of the system must be installed at the PNM point of service.
- A standard form interconnection agreement between PNM and the customer must be signed before the system can be interconnected to the PNM system.
1. Download the interconnection application form. You can also request an application for interconnection by contacting PNM.
Customer Generation Programs
Albuquerque, N.M. 87158-0510
2. When your project plans are finalized, complete the application for interconnection and return it along with the application fee to PNM to the address below. An application fee of $50 for qualifying facilities with a design capacity less than 100 kilowatts and $500 for qualifying facilities with a design capacity of 100 kilowatts or greater is required. The application must include a copy of the inverter manufacturer's specification sheet showing the inverter's rating and its listing under UL 1741.
If another form of interconnection protection is used, a list of the protective devices associated with the interconnection and the operating procedure is needed. The application will also need to include a simple one-line diagram of the proposed system. For installations where the customer generation disconnect switch (utility-accessible disconnect switch) is not located adjacent to the PNM metering point, a simple site diagram showing the physical locations of all key components of the system is required. The system one-line and site diagram drawings must identify all major equipment including the inverter, electric service panels, the customer generation disconnect switch and the PNM metering point. These last two items must be clearly labeled on the one-line diagram.
Placement of the one-line diagram, site map and safety signage depend on where the REC meter and billing meter (also known as the net meter) are located. See detailed diagrams of the different scenarios (PPT).
PNM will not process or approve projects without finalized project plans.
The operating procedure, one-line electrical diagram and, if required, the site diagram are critical components of the application for interconnection and will become part of the Interconnection Agreement. Deficiencies in the operating procedure, one-line diagram and site drawing are the most common cause for delays in PNM's review and approval of an application for interconnection.
If there are any questions or concerns about the application or about the interconnection plans, PNM will contact you or your contractor for clarification to resolve the interconnection concerns. If the application is complete and the interconnection plans are acceptable, PNM will approve the interconnection design.
To avoid unnecessary cost and delay, it is recommend that PNM's approval of the final interconnection design be obtained prior to purchasing material or equipment for the project.
After the application has been approved, PNM will send you two originals of the standard form Interconnection Agreement required by NMPRC Rule 17.9.570. Both originals of this agreement will need to be signed by you, the PNM customer/generator owner who is requesting the interconnection. You then return both of the signed originals to PNM for PNM's signature.
PNM will execute the Interconnection Agreement when all inspections are complete and the generating system has been authorized to commence interconnected operation.
After construction of the generating system is complete and after it has received the final electric inspection from the local building codes authority, you or your contractor will need to contact PNM for an interconnection approval inspection. The purpose of PNM's inspection will be:
- to verify that the facility has been constructed as it is represented in the application and in the Interconnection Agreement
- to verify that the anti-islanding and other interconnection protection of the generator is operational
- to install permanent warning signs, and to verify that a permanent weatherproof copy of the one-line diagram and, if required, a site drawing have been installed at the point of metering. See three different ways, using a drawing tube, mail slot or permanent label, to permanently store the one-line diagram.
PNM interconnection inspections normally can be scheduled within 10 working days of receiving a request.
After the interconnection has passed PNM's inspection, PNM will provide written authorization for you to commence interconnected operations of your system. The written authorization to commence interconnected operation is an attachment to the fully executed Interconnection Agreement.
PNM will return one of the fully executed agreements to you, the customer/generator owner, and PNM will file a copy of the fully executed agreement with the New Mexico Public Regulation Commission.
The generating system may not be operated in parallel with PNM's system without PNM's written authorization to do so.
Three general metering options are available under NMPRC rule 17.9.570:
- Load displacement: If you wish primarily to serve your own load, PNM will interconnect your facility using a single meter or meter set to measure flow from PNM to your facility. Billing for any power from PNM will be at PNM's approved tariff applicable to the service provided to your facility. There will be no additional customer charges and no payment by PNM for any excess energy that might be generated by your facility.
- Net metering: PNM will install an additional meter to measure separately the energy generated by your facility, and then calculate net energy consumed or supplied by your facility. You will be paid for energy supplied above the amount consumed at PNM's Cogeneration and Small Power Production Rate No. 12. These rates are based on PNM's avoided cost of generation. There will be an additional PNM charge for the specialized metering required. Contact PNM for an estimate of what the additional cost is for your situation.
- Separate load metering (simultaneous buy / sell): PNM will install an additional meter (three meters total) to measure separately all the energy produced and power consumed by your facility. PNM will purchase all the energy produced by your system at PNM Rate 12. You will purchase all power consumed by your facility at your normally applicable rate. There will be an additional PNM charge for the specialized metering required. Contact PNM for an estimate of what the additional cost is for your situation.