Implications for Filipino Electrical Engineers and the Philippine Electrical Code (PEC)
1. Introduction to EMS in NEC 2023
The 2023 edition of the National Electrical Code (NEC) introduced Section 220.70 to formally recognize Energy Management Systems (EMSs) in the context of electrical load calculations. The definition provided by NEC describes EMS as:
"A system consisting of any of the following: a monitor(s), communications equipment, a controller(s), a timer(s), or other devices that monitor and/or control an electrical load or a power production or storage source."
This provision allows the use of EMS setpoints to limit the current on a feeder or service, thereby impacting how load calculations are performed.
2. Rationale Behind the Inclusion of EMS in NEC 2023
The inclusion of Section 220.70 addresses several emerging trends and technical needs:
2.a. Increasing Use of Smart Technologies
Modern buildings are increasingly deploying smart energy controls to reduce demand, integrate renewable sources, and increase efficiency. EMSs help manage peak loads by controlling or shifting energy usage in real time.
2.b. Promoting Energy Efficiency
The U.S. Department of Energy and energy codes like ASHRAE 90.1 emphasize demand-side management. NEC 220.70 supports this by letting EMS-managed setpoints be used in load sizing, enabling smaller service equipment while maintaining safety.
2.c. Integration with DER and BESS
EMS is vital for managing Distributed Energy Resources (DER) like solar PV and Battery Energy Storage Systems (BESS). NEC 2023 responds to the evolving grid structure, where managing local generation and consumption is crucial.
2.d. Cost and Infrastructure Optimization
By using EMS-controlled setpoints, engineers can right-size feeders, transformers, and panels, leading to cost savings in materials, installation, and operational expenditures.
3. Key Provisions of NEC 2023 Section 220.70
| Clause | Description |
|---|---|
| Setpoint Use | EMSs may set a maximum ampere value (setpoint) for feeders or services. |
| Load Calculation | The EMS setpoint value is used as the basis for load calculations instead of traditional demand factors. |
| Continuous Load | The setpoint is treated as a continuous load, ensuring conservative and safe load sizing. |
| Reference to 750.30 | This clause references Article 750.30, governing the operational reliability and compliance of load control systems. |
4. Advantages of EMS Provision in NEC 2023
4.a. Engineering Benefits
- Smaller Service Entrance Ratings → Reduces transformer sizes and wire gauges.
- Better Load Balancing → Efficient distribution of electrical loads across phases and time periods.
4.b. Operational & Financial Benefits
- Reduced Demand Charges → By limiting peak loads.
- Increased Energy Visibility → Real-time monitoring allows corrective action.
- Supports Renewable Energy & BESS → Enables dynamic load shifting and storage optimization.
4.c. Sustainability & Grid Benefits
- Demand Response Participation → EMS allows buildings to participate in utility programs.
- Load Flexibility → Key to a resilient and decarbonized grid.
5. Recommendations for Inclusion in the Philippine Electrical Code (PEC)
Given the benefits and alignment with global trends, it is strongly recommended that the Board of Electrical Engineering and IEE of the Philippines (IIEE) consider adopting an equivalent of NEC 220.70 into the next PEC revision.
5.a. Proposed PEC Amendment:
“An Energy Management System (EMS) may be used to set a maximum current value for feeders or services. This setpoint may be used as the basis for load calculations, provided the EMS complies with applicable control standards and failsafe operations.”
5.b. Policy and Design Recommendations:
- Define EMS formally in PEC Rule 2 or 3.
- Set minimum standards for EMS hardware and software reliability.
- Align with RA 11285 (Energy Efficiency and Conservation Act) for public and large private buildings.
- Encourage LGUs and utilities to support EMS use in commercial, industrial, and residential installations.
6. Conclusion
The inclusion of Energy Management Systems in NEC 2023 under Section 220.70 is a progressive move acknowledging the role of intelligent load management in modern power systems. As the Philippines modernizes its infrastructure, integrating EMS provisions in the Philippine Electrical Code (PEC) will support grid stability, cost efficiency, and compliance with sustainable energy goals.
7. References:
- NEC 2023 Section 220.70
- NEC 2023 Article 750.30
- ASHRAE Standard 90.1-2022
- Republic Act No. 11285 – Energy Efficiency and Conservation Act (Philippines)
- PEC 2017 and its development based on NEC 2005/2008