In simple terms, grid-connected means "connected to the public power grid" – allowing electricity to be exchanged with the grid; while off-grid means "not connected to the public power grid" – generating and using electricity independently.
The system is linked to the public power grid. When the PV system generates more electricity than is used, the surplus can be sold to the grid; when the PV output is insufficient (e.g., on cloudy days or at night), additional electricity can be purchased from the grid.
Example: For a balcony micro-storage system, excess electricity generated during the day is fed into the grid, and electricity is drawn from the grid to supplement supply at night.
This mode operates independently of the public grid. For instance, during a power outage, the system relies on its own PV panels and batteries to supply electricity, without using power from the grid.
Example: In a residential PV-storage system, "off-grid loads" (such as refrigerators and lights) can still work normally during a power outage, powered by the system’s own energy storage.
Residential PV systems often suffer from reduced power generation efficiency due to component shading or inverter malfunctions. Additionally, users struggle to accurately calculate the total power generated and the revenue from electricity savings or sales.
Solution:
Monitoring devices enable real-time tracking of power generation from individual PV strings and the electricity exchanged with the grid. Specifically, the dual-circuit function of the
ADL200M/400M can distinguish between data on direct PV power supply and energy storage charging/discharging. This not only helps users identify underperforming components or faulty equipment but also accurately calculates revenue from surplus electricity fed into the grid, preventing revenue loss.
Regions such as Europe and North America mandate anti-reverse power flow monitoring for residential PV systems; non-compliant grid connection may result in heavy fines.
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Local Grid Overload: When a large number of users feed surplus electricity into the grid simultaneously, it may cause overload and overheating of equipment such as distribution transformers and power lines, accelerating aging or even leading to damage.
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Voltage Exceedance and Deteriorated Power Quality: Local grid voltage may rise beyond the rated range (e.g., 230V ± 10%), potentially damaging electrical appliances in neighboring households. It may also introduce harmonic pollution.
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Islanding Effect: If a user’s PV/energy storage system continues operating and supplies power to local lines during a grid outage, it poses a life-threatening risk to power maintenance personnel.
Solution:
The
ADL200W/400W monitors grid-connected current in real time and coordinates with inverters to achieve rapid current limiting, ensuring compliance with grid-connection regulations.
Residential PV systems are scattered across locations, leading to high costs for manual inspections and delayed fault detection.
Solution:
The
ADL200W/ADL400W supports WIFI-enabled remote data upload. Users and O&M personnel can monitor the system’s operating status in real time via mobile phones or a dedicated platform. In case of issues such as abnormal voltage or metering deviations, the system automatically sends alert notifications, enabling rapid fault localization and significantly reducing O&M costs.
The translation maintains a technical yet accessible tone, balancing accuracy for industry professionals (e.g., specifying model numbers like ADL200M) and clarity for end-users (e.g., explaining "islanding effect" with safety implications). It also retains the original structure of "Challenge → Hazard (if applicable) → Solution" to ensure logical flow for documentation or client presentations.
