Power outages in factories, hospitals, or shopping malls not only cause inconvenience but can also lead to significant economic losses. To address this issue, dual-source energy meters have been developed. This article will briefly introduce the role and value of dual-source energy meters from the aspects of definition, working principle, types, and application scenarios.
What is dual source energy meter
A dual-source energy meter is a specialized device that accurately measures the energy from both the main grid and backup power sources. It aims to help users optimize backup system management and ensure continuous and stable system operation. It clearly displays the energy source, distinguishing between energy consumption from the main grid and backup power sources (such as diesel generators or inverters), thereby assisting users in cost management, downtime risk control, and power optimization. For example, in many countries, the price of electricity from the main grid is often lower than the cost of using backup power. With a dual-source energy meter, users can clearly understand the usage of backup power sources (such as diesel generators), avoid excessive fuel consumption, and ensure timely critical maintenance.
Dual Source Energy Meter Working Principle
Dual source energy meters typically employ a dual-voltage input and multi-current acquisition architecture to measure the main power supply and backup power supply separately. Their working principle includes:
- Voltage Acquisition: Voltage signals from the main grid and backup power supply are acquired through independent voltage input lines, ensuring isolated measurement of the two power sources.
- Current Acquisition: Current transformers (CTs) monitor the load current of each power source, and combined with voltage data, calculate parameters such as power, energy, and power factor in real time.
- Data Processing and Switching Monitoring: The internal microprocessor digitizes the acquired voltage and current data, calculating active power (kW), reactive power (kVAR), total energy (kWh), and other power quality indicators from each power source.
- Communication and Integration: Through Modbus or other communication protocols, dual source energy meters can upload measurement data to an energy management system (EMS/PMS/SCADA) in real time, enabling remote monitoring and analysis of power consumption.
- Switching analysis: When switching occurs between the main power supply and the backup power supply, the meter can record the power data at the switching point in real time, providing a basis for load balancing, shutdown analysis and maintenance decisions.
Dual source power meter Types
Single-phase dual-source energy meter: For homes, small offices, or retail stores using basic 230V power. Only one live wire and one neutral wire are needed. This meter tracks power from the main grid connection as well as power from an inverter or backup generator. Affordable and compact, suitable for small systems.
Three-phase dual-source energy meter: For factories, hospitals, and data centers. Designed to handle complete 415V or higher systems, it measures the energy flow in each of the three power lines (A, B, C) separately for more advanced diagnostic functions such as power factor load curve analysis and per-line energy loop locking.
Dual source kwh meter Applications
Data Center: Accurately tracks the energy consumption of primary and backup power systems (such as UPS and diesel generators) to ensure adequate backup power capacity, proper maintenance, and reliability, enabling them to cope with continuous power outages.
Hospitals: Continuous Power – Powering life-saving equipment such as ventilators, diagnostic equipment, operating rooms, or intensive care units (ICUs) is crucial; a single power outage can endanger patient lives. Dual-source energy meters accurately provide insights into the energy consumption of primary and backup generators, helping hospitals efficiently maintain their power generation systems, accurately plan for demand, and ensure emergency systems function optimally when needed.
Factories and Manufacturing Plants: Rely on a continuous power supply to avoid material waste, equipment and machinery damage, and severe economic losses due to power outages. Dual-source energy meters separately measure and monitor the power consumption of primary and backup power sources. This accurate data helps industries proactively schedule generator maintenance, optimizing energy costs and reducing downtime, ensuring stable operation even during unexpected power outages.
Smart grids and microgrids: Typically use a mix of energy sources, including solar panels, wind turbines, diesel generators, and of course, the main grid. Dual-source energy meters help track how much energy is consumed from each source. This is crucial for optimizing electricity use, controlling costs, and ensuring stability, especially when switching between variable and traditional power sources throughout the day.
Dual-Source Meters vs. Net Meters
In solar power or microgrid systems, the use of net meters depends on the specific application scenario: when energy is mainly consumed locally and not fed back to the grid, dual-source meters can separately record the energy flow of the main power source and the backup or renewable power source, better supporting energy management and cost control; while in some systems that can interact with the grid, dual-source meters and net meters can be used simultaneously to achieve the dual functions of internal monitoring and grid settlement.
| Comparison Item | Dual Source Energy Meter | Net Metering Meter |
| Applicable Scenarios | Microgrids, local consumption-focused systems, backup power (generator/inverter) monitoring | Grid-tied distributed energy systems, solar or wind energy feeding back to the grid |
| Measured Object | Separately records energy from main power and backup/renewable sources | Records total energy flow and calculates net energy sent to or drawn from the grid |
| Data Accuracy | Provides granular, independent multi-source monitoring | Accurate for net energy sent to grid vs. consumption, but cannot distinguish internal source flows |
| Energy Management | Supports backup power management, load analysis, and cost optimization | Mainly for grid settlement; limited capability for internal energy management |
| Key Advantages | Optimizes energy use, schedules generator maintenance, reduces downtime risk | Enables net energy billing with the grid |
| Combined Use | Can be used alone or together with a net metering meter | Can be combined with a dual source meter for both grid settlement and internal monitoring |
Installation Notes for Dual Source kWh Meter
CT Selection & Rating
- Select appropriate rated current transformers (CTs), e.g., 100/5A, 200/5A, 300/5A, or higher, according to the system load.
- Strictly check CT polarity and orientation during installation. Incorrect connections can lead to inaccurate meter readings.
Panel Installation & Space Planning
- Confirm the dimensions of the panel or distribution board and determine whether the meter is flush-mounted or fully installed.
- Reserve sufficient space for voltage terminals, communication cables, and wiring, especially in compact power plant environments.
Voltage Input Wiring & Source Isolation
- Each power source (generator, solar, etc.) must be connected separately to the meter’s voltage input.
- Ensure physical isolation between main and backup power voltage lines to prevent interference and measurement errors.
Integration with PMS/EMS/SCADA
- After installation, test Modbus address, baud rate, and parity to ensure reliable data communication.
- Verify that the system can upload real-time energy consumption data to the energy management platform for remote monitoring and analysis.
Conclusion
Dual-source energy meters provide precise monitoring of both main and backup power, enabling efficient energy management, cost optimization, and reduced risk of downtime. Suitable for homes, factories, hospitals, data centers, and microgrids, they offer greater visibility than net meters in systems with local consumption or backup generation. Proper installation ensures accurate data and seamless integration with energy management platforms, supporting reliable and resilient power operations.
