SolarEdge inverter + battery — `solaredge_modbus` setup guide

Tested against the SolarEdge SE10K-RWS three-phase inverter with StorEdge battery interface, firmware 4.24.x. Should work on the single-phase HD-Wave family and the three-phase RWS family. Modbus TCP is the path; cloud-API is not used.

Prerequisites

A SolarEdge inverter with Modbus TCP enabled. Most SE inverters support it but it's OFF by default. Enable via:
SetApp (modern installs): Site Communication → Modbus TCP → On, port 1502 (or your choice).
Older inverters with LCD: Communication → Server → LAN, then under Modbus TCP enable + set port.
Wired or WiFi network connection between your Otonomo box and the inverter. WiFi works but a wired link is more reliable. StorEdge battery readings update every ~5 s; a flaky link will show gaps.
A known IP address for the inverter. Reserve one via your router's DHCP table. The SolarEdge mobile app shows the IP under Site Communication.

Verifying reachability

Before configuring the driver, confirm you can reach the inverter over Modbus TCP from your Otonomo box:

# From your Otonomo box:
nc -vz <inverter-ip> 1502     # should say "open"

If that fails: inverter Modbus not enabled, wrong IP, or firewall.

Configuring the driver

Open the local UI at http://<box-ip>:8080/drivers.
Find solaredge_modbus under "PV Inverter" and click Install.
Click Add instance:

Field	Value	Why
Instance ID	`solaredge_modbus.pv`	Unique on this box
`host`	`192.168.x.y`	Your inverter's IP (required)
`port`	`1502`	SolarEdge default (NOT 502)
`unit_id`	`1`	Always 1 for SolarEdge
`timeout_s`	`3.0`	Inverter is slow on standby; 3 s is safe

Click Create instance.

Within ~30 seconds:

pv.power_w updates
battery.soc_pct + battery.power_w if you have a StorEdge battery
grid.power_w if you have the SE grid meter installed (Model 203)

Verifying

http://<box-ip>:8080/device/solar — Solar Now + Solar Today cards. http://<box-ip>:8080/device/battery — Battery SOC + Battery Power. http://<box-ip>:8080/device/grid — Grid Power if meter present.

If only Solar shows up, the battery / grid meter aren't being polled — check the inverter's "Device Manager" view in SetApp; battery + meter appear there if SolarEdge sees them.

Common pitfalls

"DeviceUnreachable: ConnectionRefusedError"

Modbus TCP not enabled on the inverter, OR the inverter is in its nightly self-test (~22:50 local for ~80 s — SolarEdge safety routine, NOT a crash). If the error persists past midnight, SetApp the inverter and re-toggle Modbus TCP.

Battery showing wrong sign / direction

SolarEdge's Modbus reports battery power with a vendor-specific sign convention: negative when charging, positive when discharging. The Otonomo driver normalises this so positive = charging in our canonical schema. If your dashboard shows opposite, you're hitting a firmware variation — let us know via support@otonomo.be with your inverter model + firmware version.

Inverter on WiFi shows two IPs

Some SolarEdge inverters have BOTH ethernet AND WiFi active and listen for Modbus on both. Either works — pick whichever is more reliable on your network. Wired wins almost always.

Grid power drifts vs per-phase sum

On firmware 4.24.22, the SunSpec Model 203 meter's total_W (offset 18) is the canonical grid reading. Per-phase sums (WphA + WphB + WphC) drift by ~600 W at low power. The Otonomo driver uses the total — don't try to derive it yourself.

"AC clipping at 8 kW" but inverter is rated 10 kW

This is expected for SE inverters running into a backup-power configuration with an upstream contactor. Status code 5 ("THROTTLED") means the inverter is curtailing on the AC side, not a DC limit. Nothing to do.

What Otonomo will do with this driver

In observe mode: - Polls PV power, battery SOC, battery power, grid power every ~10 s - Visualizes on the dashboard, runs cloud orchestrators in shadow

In active mode, with Battery dispatch opt-in: - Writes battery mode (StorCtl_Mod register) to schedule charging from grid during cheap hours - Writes export limit to prevent injection during negative pricing - Falls back to MaxSelfConsume on cloud-watchdog safe-mode

You can pause optimization at any time with the per-capability switch in /account/control. The inverter resumes its prior internal schedule within ~60 s of the cloud yielding control.

Two-driver pattern (advanced)

For large fleets where the inverter is heavily polled, we use a split-driver pattern: a read-only solaredge_modbus polling instance + a separate solaredge_modbus_write actuator that opens a Modbus connection only when writing. This avoids the SE firmware's intolerance for two always-connected Modbus clients.

Most home installs don't need this. The single-driver setup above works fine for one Otonomo box per inverter. If you see "ConnectionReset" errors at high write frequency, ask support@otonomo.be about the split pattern.

References

SolarEdge SunSpec Modbus implementation note: https://www.solaredge.com/sites/default/files/sunspec-implementation-technical-note.pdf
SunSpec Information Models: https://sunspec.org/wp-content/uploads/2015/06/SunSpec-Information-Models-12041.pdf
Otonomo driver source — otonomo_drivers/drivers/solaredge_modbus/

Otonomo's solaredge_modbus is an independent interoperability tool. Not affiliated with SolarEdge Technologies.

SolarEdge inverter + battery — solaredge_modbus setup guide