The Deye SUN-K-G series are three-phase grid-tied inverters (on-grid) designed for stable operation in both domestic and commercial installations, where high energy yield and reliable grid cooperation are key. The standout feature of this series is multi-channel MPPT tracking - depending on the version, there are two or even four MPPT channels available, facilitating the design of roof installations with different orientations and helping minimize losses due to partial shading. In practice, this translates to better matching the performance of PV strings to conditions throughout the day.
The applied high European efficiency means that the inverter maintains good efficiency not only in ideal laboratory conditions but also in typical, variable operating conditions - which realistically supports the annual energy yield in Poland. Available features for installations with power export limitations include zero export and grid support mode operation.
Monitoring can be performed remotely via the register and the app, and communication includes, among others, WiFi and optionally Ethernet. The series features European grid connection certificates and is covered by the manufacturer's warranty.
Ranking
Specifications
Pros and cons
Models from the SUN-4/5/6/7/8/10K-G03 series achieve a maximum efficiency of 98.3%, while European efficiency (weighted) is approximately 97.7%. This translates to significantly higher annual yields under variable solar conditions typical of Poland, where operating at full power is rare.
These inverters are equipped with either 2 MPPT tracks (4-10 kW versions) or 4 MPPT tracks (higher power versions), with a wide voltage range of 200-850 V. This allows for flexible design of PV systems on multi-pitched roofs and minimizes losses due to partial shading without the need for optimizers.
The built-in zero export feature allows for limiting energy output to the grid without additional external meters - crucial for installations with network-specific OSD (Operator-Specific Requirements). The Virtual Synchronous Generator (VSG) technology supports grid stability and meets the stringent connection requirements of European operators.
The series has European certification required in the Polish market (VDE-AR-N 4105, EN 50549) and an IP65 degree of protection, which allows for installation outdoors without additional enclosures and reduces the installation time.
The built-in WiFi module, with support for the SolarmanPV application (GPRS/4G/LAN optional), enables remote diagnostics and production analysis. The Modbus RTU/TCP protocol allows integration with BMS and EMS systems without the need for additional converters.
The SUN-K-G series was discontinued by Deye in 2022 and replaced by newer lines (G04, G05). This means limited availability of original spare parts, a lack of firmware updates, and potential servicing difficulties after the warranty period expires - which is particularly relevant in the context of a 15-20-year lifespan for PV installations.
The standard warranty for the SUN-K-G series is 5 years, while newer Deye (hybrid SG) lines offer a 10-year warranty, and competitors (e.g., SMA, Fronius) provide a 5-year warranty with the option to extend it to 20 years through service packages. A shorter warranty period represents an additional risk when purchasing a product from a discontinued line.
Alternatives
About the SUN-K-G series
These answers cover the whole series. Where a figure differs, the specification above is this model's own.