diff --git a/plugin.py b/plugin.py
index 1e3e51c..f4619ab 100644
--- a/plugin.py
+++ b/plugin.py
@@ -392,7 +392,7 @@ def transform_solar_charger_data(
             },
             {
                 "path": f"electrical.solar.{id_}.yieldToday",
-                "value": data.get_yield_today(),
+                "value": data.get_yield_today() * 3600, // SignalK expects Joules
             },
         ]