core/homeassistant/components/osoenergy/icons.json

{
  "entity": {
    "binary_sensor": {
      "power_save": {
        "default": "mdi:power-sleep"
      },
      "extra_energy": {
        "default": "mdi:white-balance-sunny"
      },
      "heating": {
        "default": "mdi:water-boiler"
      }
    }
  }
}