diff --git a/ecologits/log.py b/ecologits/log.py
index eea436a..edf05a3 100644
--- a/ecologits/log.py
+++ b/ecologits/log.py
@@ -1,3 +1,32 @@
 import logging
 
+
+class EcoLogitsLogger(logging.Logger):
+
+    def __init__(self, name, level=logging.NOTSET):
+        super().__init__(name, level)
+        self.__once_messages = set()
+
+    def _log_once(self, level, msg, *args, **kwargs):
+        if msg not in self.__once_messages:
+            self.__once_messages.add(msg)
+            self.log(level, msg, *args, **kwargs)
+
+    def debug_once(self, msg, *args, **kwargs):
+        self._log_once(logging.DEBUG, msg, *args, **kwargs)
+
+    def info_once(self, msg, *args, **kwargs):
+        self._log_once(logging.INFO, msg, *args, **kwargs)
+
+    def warning_once(self, msg, *args, **kwargs):
+        self._log_once(logging.WARNING, msg, *args, **kwargs)
+
+    def error_once(self, msg, *args, **kwargs):
+        self._log_once(logging.ERROR, msg, *args, **kwargs)
+
+    def critical_once(self, msg, *args, **kwargs):
+        self._log_once(logging.CRITICAL, msg, *args, **kwargs)
+
+
+logging.setLoggerClass(EcoLogitsLogger)
 logger = logging.getLogger(__name__)
diff --git a/ecologits/tracers/utils.py b/ecologits/tracers/utils.py
index 494b0ee..06b77e6 100644
--- a/ecologits/tracers/utils.py
+++ b/ecologits/tracers/utils.py
@@ -75,8 +75,9 @@ def llm_impacts(
 
     model = models.find_model(provider=provider, model_name=model_name)
     if model is None:
-        logger.debug(f"Could not find model `{model_name}` for {provider} provider.")
-        return ImpactsOutput(errors=[ModelNotRegisteredError()])
+        error = ModelNotRegisteredError(message=f"Could not find model `{model_name}` for {provider} provider.")
+        logger.warning_once(str(error))
+        return ImpactsOutput(errors=[error])
 
     if isinstance(model.architecture.parameters, ParametersMoE):
         model_total_params = model.architecture.parameters.total
@@ -87,8 +88,11 @@ def llm_impacts(
 
     electricity_mix = electricity_mixes.find_electricity_mix(zone=electricity_mix_zone)
     if electricity_mix is None:
-        logger.debug(f"Could not find electricity mix `{electricity_mix_zone}` in the ADEME database")
-        return ImpactsOutput(errors=[ZoneNotRegisteredError()])
+        error = ModelNotRegisteredError(message=f"Could not find electricity mix `{electricity_mix_zone}` in the "
+                                                f"ADEME database.")
+        logger.warning_once(str(error))
+        return ImpactsOutput(errors=[error])
+
     if_electricity_mix_adpe=electricity_mix.adpe
     if_electricity_mix_pe=electricity_mix.pe
     if_electricity_mix_gwp=electricity_mix.gwp
@@ -105,6 +109,7 @@ def llm_impacts(
 
     if model.has_warnings:
         for w in model.warnings:
+            logger.warning_once(str(w))
             impacts.add_warning(w)
 
     return impacts