Karl's Energy Upgrade Case
Karl, a homeowner in Bavaria, Germany, installed a 5kW solar system years ago. However, as his energy needs increased, particularly with the addition of an electric vehicle, he noticed that surplus solar power during the day wasn’t being utilized effectively, while nighttime electricity costs were high. To solve this, he added an AC-coupled storage inverter and a 10kWh battery to his existing system. This upgrade boosted his solar self-consumption rate to 85%, saving him around €800 annually, and ensured continuous power supply during outages.
Understanding AC-Coupled Technology
AC coupling is a cutting-edge technology that connects solar, storage, and grid systems via an AC bus, offering enhanced flexibility and efficiency for distributed energy systems.
What is AC Coupled?
AC Coupled refers to an architecture that connects multiple energy systems via an AC bus, transmitting energy between components through AC current. Unlike traditional DC Coupled systems, which directly connect the solar inverter, storage inverter, and the grid using DC current, AC Coupled systems link these components using AC. The main components of an AC Coupled system include:
- Solar Inverter: Converts the DC electricity generated by solar panels into AC electricity for the grid or load.
- Storage Inverter: Converts the DC electricity from the battery into AC or charges the battery from the AC power source.
- Grid or Off-Grid Power Source: Provides the reference frequency for the system and connects to the load, ensuring stable operation.
How It Works
1. Grid-Tied Mode: Surplus solar energy charges the battery during the day; energy is discharged during peak demand periods at night.
2. Off-Grid Mode: During outages, the storage inverter maintains power supply by managing PV and battery operations.
3. Priority Settings: Users can prioritize solar power or battery discharge based on electricity rates or consumption needs.
Benefits of it
- Flexibility: AC Coupled systems allow users to add storage modules to existing PV systems without replacing the original solar inverter.
- Compatibility: AC Coupled systems support a wide range of devices from different brands and models, making them suitable for multi-brand system integration.
- Efficiency: The system optimizes energy scheduling to enhance overall system efficiency, increasing solar self-consumption and reducing dependence on the grid.
- Cost-Effectiveness: The system intelligently schedules energy use, reducing peak period electricity consumption and lowering electricity costs.
- Adaptability: For homes or businesses with existing traditional PV systems, AC Coupled provides an ideal upgrade solution without the need for large-scale equipment replacement.
Application Scenarios for AC Coupled Systems
Due to its unique advantages, AC Coupled systems are suitable for various applications, particularly in household energy storage, small commercial use, and microgrids in remote areas.
1. Home Storage Upgrades
Many homeowners have installed PV systems, but as their energy consumption increases, they wish to add storage to improve self-consumption. AC Coupled systems provide an ideal solution, as they only require adding storage modules without replacing the existing solar inverter.
2. Small Commercial Projects
For small commercial users, AC Coupled systems help smooth out electricity price fluctuations, lowering long-term electricity costs. By intelligently scheduling storage and solar energy, commercial users can use stored power during peak periods to avoid high peak rates.
3. Remote Areas or Microgrids
In areas without grid access or with unstable grids, AC Coupled systems provide stable power supply through the storage inverter, integrating solar, wind, and other power sources into an independent microgrid system for continuous power supply.
4. Grid Interaction Projects
In countries supporting Virtual Power Plants (VPP) and demand response, AC Coupled systems with storage inverters can participate in grid scheduling, providing backup power support, optimizing grid load, and enhancing system stability.
Hinen AC5000s Solution
Hinen AC5000s is an AC Coupled storage inverter specifically designed for PV storage upgrades, catering to users like Karl who wish to upgrade their solar systems. Its key features include:
1. Efficient Energy Storage: Manages energy flow in real-time, storing excess energy in the battery when solar power is abundant and drawing energy from the battery during peak consumption periods to optimize energy usage.
2. Grid Forming Capability: Ensures the entire solar system, including the PV inverter, continues to function normally even during a grid outage, maintaining power stability.
3. Ultra-Fast Switching: In the event of a power outage, Hinen AC5000s switches to off-grid mode within 10 milliseconds, ensuring uninterrupted power supply for household or commercial loads.
4. Dual CT Design: Provides real-time monitoring of PV inverter generation power, enabling precise anti-backflow control to enhance system safety and efficiency.
5. Intelligent Monitoring: Through a dedicated app, users can monitor the system’s operational status in real time, access data, and manage the system remotely with ease.
6. Easy Installation: Simple setup and flexible expansion that do not interfere with existing PV wiring, making it cost-effective and ideal for retrofit projects.
7. Wide Compatibility: Designed with LiFePO4 battery cells, it supports single-cluster or multi-cluster parallel expansion, with up to six inverters in parallel, delivering a maximum output of 30 kW. This makes it suitable for both residential energy storage and small-scale commercial retrofits.
With Hinen AC5000s, users can achieve a seamless and efficient upgrade to their existing solar systems, maximizing energy independence and supporting sustainable energy goals.
