SolarEdge HD-Wave and Modbus TCP

SolarEdge HD-Wave single-phase and three-phase inverters expose a Modbus TCP server on TCP port 1502 (not the standard 502). Unit ID is 1 by default. This non-standard port is a common source of integration failures — always configure your gateway to use port 1502.

SunSpec Register Map

Key SunSpec registers on SolarEdge inverters: 40083 (AC power, int16, W), 40093 (AC energy lifetime, uint32, Wh), 40101 (DC voltage, uint16, 0.1V). SolarEdge also maintains a proprietary register map starting at 0x9C40 for detailed production data beyond the SunSpec standard.

KNX Integration via Modbus Gateway

KNX integration via Weinzierl BAOS 777 or MDT Modbus gateway: configure poll interval of 10 seconds for power readings and 60 seconds for energy accumulation registers. KNX group objects: DPT 9.001 (W) for AC power, DPT 13.010 (Wh) for day energy, DPT 14.068 (W) for DC power.

StorEdge Battery Integration

When a SolarEdge battery (LG Chem, SolarEdge Home Battery) is connected via the StorEdge interface, additional Modbus registers become available: 0xE140 (battery level, %) and 0xE18D (battery power, W, positive=charge, negative=discharge). Map battery power using KNX DPT 9.001 (signed float). Use KNX arithmetic objects in the gateway to derive self-consumption percentage from PV power and grid import readings.

Self-Consumption KNX Logic

StorEdge self-consumption KNX logic: compare grid power (from smart meter DT6016E Modbus registers) with PV production. When excess power exceeds 200W, switch on KNX actuators for water heater and EV charger SG-Ready relay. The SG-Ready relay state table: K1/K2 state 2 = normal operation with PV surplus enabled.

Enabling Modbus on SolarEdge

Enable Modbus TCP on SolarEdge via SetApp (Android/iOS installer app): navigate to Communication, then RS485/LAN, then Modbus TCP, then Enable. Only installer-level SetApp access enables this option — homeowner accounts cannot configure Modbus.

Firmware Version Pitfall

Critical pitfall: SolarEdge firmware v4.x changed the Modbus TCP port from 502 to 1502. If polling fails after a firmware update, verify the firmware version first. Some older MDT gateway configurations have the port hardcoded to 502 and require manual correction in the gateway web interface after a SolarEdge firmware upgrade.

Cloud API vs Local Modbus

SolarEdge monitoring also exposes data via a cloud API (OAuth2-based) through the mySolarEdge portal, but local Modbus TCP is strongly preferred for building automation due to lower latency and independence from internet connectivity. For KNX building automation where response time and reliability matter, always use local Modbus TCP rather than the cloud API.