Interconnecting Small Facilities
Qualifying facility 10 kilowatts or smaller
PNM will authorize the interconnection of any photovoltaic, or other qualifying renewable resource, generating system rated at 10 kilowatts or less that complies with New Mexico Public Regulation Rule on net metering and PNM Interconnection and Safety Standards.
- 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.
- A single meter will normally be used for net metering.
- 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.
- PNM personnel must verify the anti-islanding operation of the inverter.
- 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. Save the interconnection application form from the link below, or request an application from PNM:
PNM Customer Generation Programs
Albuquerque, N.M., 87158-1135
2. When your project plans are finalized, complete the application for interconnection and return it along with the $50 application fee to PNM using the address above. The application must include a copy of the inverter manufacturer's specification sheet showing the inverter's rating and its listing under UL 1741. 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 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 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.
3. After the application has been approved, PNM will send you two originals of the standard form Interconnection Agreement. 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 a PNM signature.
PNM will execute the Interconnection Agreement when all inspections are complete and the generating system has been authorized to commence interconnected operation.
4. 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 protection of the inverter 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 usually can be scheduled within 10 working days of receiving a request.
5. After the interconnection has passed PNM's inspection, PNM will provide written authorization for you to commence interconnected operations. 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.
The net metering billing calculation that PNM has adopted is shown in the New Mexico Public Regulatory Commission rule on net metering. In general, this is how it works:
- PNM uses a single meter to accomplish net metering. Under most rate structures, no special metering is required to accomplish net metering so there is no additional cost to you to be net metered. However, if you wish to have time-of-use energy pricing as well as net metering, there will be an additional one-time PNM charge of $850 for the special metering equipment that is required. Contact PNM for an estimate of what the additional cost is for your situation. There will be additional wiring necessary if you choose to use two meters. Contact your electrician for an estimate of those costs.
- If electricity supplied by PNM to you exceeds the electricity generated by your system during a billing period, you will be billed for the net energy supplied by PNM. You will be billed for service in accordance with the rate structure and monthly charges that you would be assigned if you did not have customer-owned generation interconnected to PNM.
- If electricity generated by your system exceeds the electricity supplied by PNM during a billing period, PNM will credit your bill with the net kilowatt hours generated that period on the next bill. Unused credits will be carried forward from month to month.
- If you leave PNM's system, your unused credits for excess kilowatt hours generated will be paid to you at PNM's Cogeneration and Small Power Production Rate No. 12. These rates are based on PNM's avoided cost of generation.
- Contact PNM
- PNM's rate No. 12 (PDF)