Hoymiles / OpenDTU / shelly - Zero Export Solution

Hi: what about Tuya devices. I've done a small script in python to get via LOCAL Tuya the actual Amp from a smart meter. It would be amazing to use also Tuya as supported devices.
Does anyone have a video on this solution in English? Or a website article/tutorial. In the youtube video it mentions zero export with or without battery backup. Looks intriguing.

The origins were rooted in a concerted effort by several folks working on Hoymiles Reverse Engineering for Hoymiles DTU to inverter communications and cracking the encryption. Many solar end users in US and outside want to fully own their own solar data and do not want to rely on cloud services by the vendor. Especially not cloud services running on servers controlled by a Chinese company. And many want a simple to use web interface instead of installing proprietary phone apps where access to private phone data is hidden and obscured.

I am no exception! My favorite environment is still Schneider SE offering LocalInsight, local web-access to the data, cloud access optional and not required. And no required phone app for installation, commissioning and operations. We all know what can happen to code-based apps after 10-15 years, they do not run anymore and there is no one around to provide updates or fixes.

OpenDTU was started by Thomas Basler (github/tbnobody) as an alternative to AhoyDTU to provide a stable platform for larger deployment. OpenDTU Software with web browser runs on the popular $2.50 Expressif ESP32-WROOM chip, AhoyDTU is available in more experimental versions on other platforms.

One limiting factor of OpenDTU is the 10 inverter limit. It is sufficient for a German "Balkon Kraftwerk" type of setup but whole house micro-inverter solar in the US requires many more inverters to be visible and manageable. Hoymiles DTU supports 99 inverters, Enphase supports 300.
This may soon change by making OpenDTU available on the WROVER 8MB ram esp32's or the latest ESP32-3S 16N8N modules.

Hoymiles advertises "Open Energy" and supports SunSpec but the DTU's (WiFi or 915 MHz) are closed units, accessible only via a cell phone app and giving no device and no port identification in a port scanner, nothing "Open" at all. I won't allow any device on my LAN that hides and conceals communications outside my LAN. I like the Hoymiles inverters, but closed DTU's are unacceptable for me. Love my dual OpenDTU (WiFi 2.4 Ghz and 915 MHz, $60 + shipping from Germany), local access via web-browser, no need to install an app and no cloud connection. Took 5 minutes to set it up and connect it to a separate isolated Home Automation LAN segment xxx.xxx.4.xxx

Here is a github link to the next step in expanding OpenDTU for battery management (scroll down to see history in English) :
OpenDTU + Battery

New hardware is being offered for more powerful integration of supporting devices
OpenDTU Fusion Board

selbstbau-pv.de offers the hardware to perform export control: using Shelly power metering and adding an export controller (129 EUR) for modulating PV output to achieve 0 export. Planning to order a unit to add active power controls to the Hoymiles Scheider XW-6848 backup system I'm testing. I'm using already manual power on/off on individual Hoymiles inverters via the OpenDTU webbrowser for emulating how active power controls would work with XW inverters when they approach full SOC. Hoymiles inverters do work with XWPro FW (frequency watt shifting) but I want an active solution using active power controls and keep off-grid frequency constant at 60 Hz.

Here is a sample OpenDTU display for a 4-string 2kW Hoymiles inverter connected to 50V batteries for testing.
(Note: the internal inverter capacitors need to be pre-charged via a resistor before being hard-connected to the DC source!)

OpenDTU - HMS-2000-4T on AGM Batteries.png
Last edited: