OpenDTU-compatible inverters: How to use balcony power plants without the cloud

Mar 20, 2026
OpenDTU kompatible Wechselrichter: So nutzen Sie Balkonkraftwerke ohne Cloud

For tech-savvy users with balcony power plants or small solar systems, OpenDTU is no longer an insider tip. The project enables the monitoring of Hoymiles micro-inverters without the data being transferred to a manufacturer cloud. In this article, we explain which inverters are suitable for OpenDTU, how data can be read live, and why this solution is particularly suitable for home and balcony power plants.

Market Trends in Decentralized Energy Monitoring

The market for balcony power plants and mini-PV systems is growing rapidly in Germany. Many users want to know how much solar power is generated per day, week, or month, without relying on a proprietary app or cloud services. Energy industry studies show that more and more private users prefer their own monitoring solutions that can be integrated into home automation systems like Home Assistant or into their own visualizations via MQTT.

At the same time, demand for compatible inverters that work with OpenDTU or similar DIY DTUs is increasing. Hoymiles micro-inverters are particularly in demand, as they enable modular, compact systems for balcony power plants and small rooftop installations.

Why OpenDTU is attractive to tech-oriented users

OpenDTU is a DIY-based DTU solution that communicates via the radio interface of Hoymiles micro-inverters. Unlike many manufacturer clouds, communication remains local within the home network or private WLAN, so no data is automatically sent to the internet.

Key advantages include:

  • Real-time monitoring of generation, voltage, frequency, and power of individual modules.

  • No obligation to use a cloud platform or manufacturer app.

  • Integration into custom visualization tools such as Grafana, Home Assistant, or PV dashboard with MQTT.

This combination makes OpenDTU particularly interesting for technically adept users who want to control and analyze their balcony power plants or small PV systems themselves.

OpenDTU Compatible Inverters: Overview and Models

OpenDTU was primarily developed for Hoymiles micro-inverters, but some variants now also support other brands such as TSUN or Solenso. It is important that the inverter has a radio interface and does not include an integrated WLAN function in its type name (e.g., "W" in the model designation for Hoymiles).

For German use and typical balcony power plants, the following series are particularly relevant:

  • Hoymiles HM series (2.4 GHz radio):

    • HM-300, HM-350, HM-400, HM-600, HM-700, HM-800, HM-1000, HM-1200, HM-1500
      These models are classic micro-inverters for PV modules in the range of 300 to 1500 watts per device and are supported by many OpenDTU variants.

  • Hoymiles HMS series (900 MHz radio):

    • HMS-300, HMS-350, HMS-400, HMS-450, HMS-500, HMS-600, HMS-700, HMS-800, HMS-900, HMS-1000, HMS-1600, HMS-1800, HMS-2000
      These devices work with a separate radio module and are also suitable for OpenDTU, as long as no WLAN is integrated.

  • Hoymiles HMT series (900 MHz radio):

    • HMT-1600, HMT-1800, HMT-2000, HMT-1800-6T, HMT-2250-6T
      These are slightly simplified variants designed for smaller or medium-sized balcony power plants.

  • Other brands (partially open-source confirmed):

    • TSUN TSOL-M350, TSOL-M800, TSOL-M1600

    • Solenso SOL-H350, SOL-H400, SOL-H800

Please note that not all devices with an integrated WLAN module (e.g., Hoymiles models with "W" in the name) are recognized by OpenDTU. Most of these WLAN variants are currently considered incompatible.

Top products for OpenDTU users

In the field of microinverters and balcony power plants, the main differences are in the power class, radio frequency, and the number of connectable modules. Below are some typical models that are mentioned as OpenDTU-compatible in practical reports and community documentation.

  • Hoymiles HM-300:

    • Power up to 300 W, one module per device, 2.4 GHz radio, ideal for small balcony or terrace systems.

    • Users appreciate the low entry barrier and easy installation, often in the range of 1-2 modules per balcony.

  • Hoymiles HM-800:

    • Power up to 800 W, two modules per device, also with 2.4 GHz radio.

    • Suitable for slightly larger balcony systems with higher expected yield and often in combination with proprietary PV software.

  • Hoymiles HMS-800:

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