Electricity Meter Selection Guide for Commercial and Industrial Photovoltaic Applications

1. Introduction

Amid the global energy transition, clean energy has become a cornerstone of many countries’ sustainability strategies. Among them, solar PV is increasingly replacing fossil fuels, helping optimize energy structures while reducing corporate energy costs and enhancing green competitiveness.

For commercial and industrial (C&I) PV systems, reliable and accurate energy data management is as critical as equipment performance. At the heart of this lies electrical energy metering: meters not only support billing and settlement but also safeguard operations, improve efficiency, and unlock the value of energy data—making their role indispensable.

2. Core Requirements for Electricity Meters in C＆I PV Systems

C&I systems face more complex conditions than residential setups—such as grid/off-grid switching, time-of-use pricing, multi-tariff assessments, high-voltage/high-current busbars, and secondary transformer circuits—leading to five core requirements for electricity meters:

Bidirectional metering—Simultaneously measures both power generation and grid power withdrawal while meeting the requirements for bidirectional active/reactive energy metering.

High accuracy—Class 0.5s/1s for active power and Class 2 for reactive power, ensuring precise billing and reliable energy efficiency assessments.

Time-of-use pricing—Support for eight or more time periods, including peak, flat, and off-peak tariffs.

Communication protocols—Compatibility with DLMS, IDIS, MODBUS and others.

Anti-interference and reliability—Stable metering accuracy, communication, and long-term operation even under harsh conditions such as high harmonics, surges, static electricity, strong magnetic fields, and frequent voltage fluctuations.

3. Application Scenarios of Metering Products in C＆I PV Systems

3.1 Smart Meters: Focusing on Compliance Metering and System-Level Energy Management

Smart meters play vital roles in C&I PV systems, including PV grid connection points, main incoming lines and feeder loops, and microgrid interfaces. At PV grid connection points, they measure both delivered and received power, forming the basis for transactions between the PV system and the grid. On main incoming lines and feeder loops, they track overall power input and consumption across the site. At microgrid interfaces, they accurately capture power exchange with the main grid, supporting stable microgrid operation.

Key advantages of smart meters :

• Compliance metering—Strict adherence to national and industry standards ensures accuracy and legitimacy of data, providing a reliable basis for billing and settlement.

• Efficient coordination—By sharing data with PV inverters and grid dispatch systems, smart meters align PV output with grid demand, improving energy efficiency.

• Flexible connectivity—Support for protocols such as DLMS, IDIS, and MODBUS, along with communication methods like 4G, RS485, and RF, enables seamless integration with energy management systems for real-time data and remote monitoring.

Product Examples:

SM380 is a three-phase smart meter for residential and C&I users. It measures power and energy in bidirectional modes, records power quality, harmonics, and event logs, with strong anti-tampering features. It supports plug-and-play communication modules for PLC/RF/GPRS/3G/4G, NB-IoT, etc., and complies with IEC and DLMS/COSEM standards.

3.2 DIN-Rail Meters: Focusing on Refined Metering in Distributed Small Spaces

DIN-rail meters are mainly used in distributed small-space scenarios, including PV array branch circuits, energy storage equipment, inverter modules, small load or backup power circuits, and auxiliary metering inside distribution boxes. In PV array branches, they measure the output of each subarray, enabling monitoring of performance and efficiency. In backup or small-load circuits, they track specific load consumption, providing data for energy optimization. In distribution boxes, they support auxiliary metering, giving a more granular view of circuit-level power distribution.

Key advantages of DIN-Rail meters:

• Space-saving—Compact form factor allows direct installation on DIN rails, minimizing space use in distribution boxes.

• Easy installation—Standardized rail mounting simplifies wiring and reduces installation time and effort.

• Cost-effective—More affordable than smart meters while still offering essential metering functions, making them suitable for large-scale deployment in distributed small-space applications.

Product Examples:

The DxSU7x Series DIN-Rail Meters can measure active, reactive, and apparent energy. It offers high accuracy, excellent sensitivity, a wide measurement range, and low self-consumption. Featuring a solid structure, soft buttons, and unique design, it supports RS-485 communication with Modbus RTU protocol and is certified by CE, RCM, and UKCA.

3.3 CT/CTVT Meters: Indirect Metering Focused on High-Voltage or High-Current Scenarios

CT/CTVT meters are widely used in high-voltage or high-current environments, such as main incoming line cabinets, transformer circuits, large-capacity load monitoring, and high-voltage grid-connected metering. In incoming line cabinets and transformer circuits, they provide accurate measurement of high-voltage power parameters, supporting transformer operation, management, and protection. For large-capacity loads, they track power consumption and operating status in real time, helping prevent overloads and equipment failures. In high-voltage grid connections, CT/CTVT meters serve as core devices for power measurement between PV systems and the high-voltage grid.

Key advantages of CT/CTVT meters:

• Adaptable to high-voltage/high-current environments—using current transformers (CTs) and voltage transformers (VTs) to safely step down high voltage and current to low levels, ensuring the safety of both metering equipment and personnel.

Product Examples:

NC34-R9.5(CT) is a next-generation CT-connected three-phase smart meter with high performance, reliable and wide measurement range for C&I users. It complies with the latest IEC and DLMS/COSEM standards. It supports local and remote energy measurement via PLC/RF/NB-IoT.

SM300-CTVT is an indirect three phase smart meter compatible for HV network monitoring. Its highly accurate and reliable performance suits substation metering. Its robust designed features for multi-range load and network measurement&monitoring, power quality enhancement and THD measurement.

4. Comparative Analysis of Different Types of Electricity Meters

5. Summary

The success of a C＆I PV project depends not only on improving generation efficiency but also on accurate data control and in-depth energy insights. Electricity meters, as the primary entry point for energy data, must be selected with attention to technical performance, lifecycle cost, compliance, and future scalability—laying a solid foundation for project value.

Looking ahead, as virtual power plants, electricity trading, and carbon markets continue to advance, electricity meters will evolve from single-function tools into“energy routers” that coordinate both energy and data flows. Choosing Linyang Energy’s smart metering solutions today means building a precise, scalable, and reliable energy data infrastructure—transforming every kilowatt-hour of green electricity into a measurable, tradable, and value-added asset.