diff --git a/pyproject.toml b/pyproject.toml
index e3d7999..a93c7af 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -4,27 +4,27 @@ build-backend = "hatchling.build"
 
 [project]
 name = "infrasys"
-version = "0.0.2"
+version = "0.0.3"
 description = ''
 readme = "README.md"
 requires-python = ">=3.10, <3.13"
 license = "BSD-3-Clause"
 keywords = []
 authors = [
-  { name = "Aadil Latif", email = "aadil.latif@nrel.gov" },
-  { name = "Daniel Thom", email = "daniel.thom@nrel.gov" },
-  { name = "Kapil Duwadi", email = "kapil.duwadi@nrel.gov" },
-  { name = "Pedro Andres Sanchez Perez", email = "pedroandres.sanchezperez@nrel.gov" },
-  { name = "Tarek Elgindy", email = "tarek.elgindy@nrel.gov" },
+    { name = "Aadil Latif", email = "aadil.latif@nrel.gov" },
+    { name = "Daniel Thom", email = "daniel.thom@nrel.gov" },
+    { name = "Kapil Duwadi", email = "kapil.duwadi@nrel.gov" },
+    { name = "Pedro Andres Sanchez Perez", email = "pedroandres.sanchezperez@nrel.gov" },
+    { name = "Tarek Elgindy", email = "tarek.elgindy@nrel.gov" },
 ]
 classifiers = [
-  "Development Status :: 4 - Beta",
-  "Programming Language :: Python",
-  "Programming Language :: Python :: 3.10",
-  "Programming Language :: Python :: 3.11",
-  "Programming Language :: Python :: 3.12",
-  "Programming Language :: Python :: Implementation :: CPython",
-  "Programming Language :: Python :: Implementation :: PyPy",
+    "Development Status :: 4 - Beta",
+    "Programming Language :: Python",
+    "Programming Language :: Python :: 3.10",
+    "Programming Language :: Python :: 3.11",
+    "Programming Language :: Python :: 3.12",
+    "Programming Language :: Python :: Implementation :: CPython",
+    "Programming Language :: Python :: Implementation :: PyPy",
 ]
 dependencies = [
     "numpy~=1.26.4",
@@ -60,9 +60,7 @@ Source = "https://github.com/NREL/infrasys"
 pythonpath = "src"
 minversion = "6.0"
 addopts = "-ra"
-testpaths = [
-    "tests",
-]
+testpaths = ["tests"]
 
 [tool.ruff]
 # Exclude a variety of commonly ignored directories.
@@ -85,12 +83,12 @@ target-version = "py311"
 [tool.ruff.lint]
 # Enable Pyflakes (`F`) and a subset of the pycodestyle (`E`)  codes by default.
 select = [
-    "C901",  # McCabe complexity
-    "E4",  # Subset of pycodestyle (E)
+    "C901", # McCabe complexity
+    "E4",   # Subset of pycodestyle (E)
     "E7",
     "E9",
-    "F",  # Pyflakes
-    "W",  # pycodestyle warnings
+    "F",    # Pyflakes
+    "W",    # pycodestyle warnings
 ]
 ignore = []
 
diff --git a/src/infrasys/component.py b/src/infrasys/component.py
index 5d502d4..5627883 100644
--- a/src/infrasys/component.py
+++ b/src/infrasys/component.py
@@ -29,7 +29,11 @@ def check_component_addition(self) -> None:
 
     def model_dump_custom(self, *args, **kwargs) -> dict[str, Any]:
         """Custom serialization for this package"""
-        refs = {x: self._model_dump_field(x) for x in self.model_fields}
+        refs = {}
+        for x in self.model_fields:
+            val = self._model_dump_field(x)
+            if val is not None:
+                refs[x] = val
         exclude = kwargs.get("exclude", [])
         exclude += list(set(exclude).union(refs))
         kwargs["exclude"] = exclude
@@ -52,6 +56,8 @@ def _model_dump_field(self, field) -> Any:
                 ),
             ).model_dump()
             val = data
+        else:
+            val = None
         # TODO: other composite types may need handling.
         # Parent packages can always implement a field_serializer themselves.
         return val
diff --git a/src/infrasys/system.py b/src/infrasys/system.py
index 146e954..6202d51 100644
--- a/src/infrasys/system.py
+++ b/src/infrasys/system.py
@@ -32,7 +32,6 @@
 )
 from infrasys.time_series_manager import TimeSeriesManager, TIME_SERIES_KWARGS
 from infrasys.time_series_models import SingleTimeSeries, TimeSeriesData, TimeSeriesMetadata
-from infrasys.utils.json import ExtendedJSONEncoder
 
 
 class System:
@@ -157,7 +156,7 @@ def to_json(self, filename: Path | str, overwrite=False, indent=None, data=None)
                 raise ISConflictingArguments("data contains the key 'system'")
             data["system"] = system_data
         with open(filename, "w", encoding="utf-8") as f_out:
-            json.dump(data, f_out, indent=indent, cls=ExtendedJSONEncoder)
+            json.dump(data, f_out, indent=indent)
             logger.info("Wrote system data to {}", filename)
 
         self._time_series_mgr.serialize(self._make_time_series_directory(filename))
diff --git a/src/infrasys/utils/json.py b/src/infrasys/utils/json.py
deleted file mode 100644
index 4d27f38..0000000
--- a/src/infrasys/utils/json.py
+++ /dev/null
@@ -1,29 +0,0 @@
-"""JSON utilities"""
-
-import enum
-import json
-from datetime import datetime, date, timedelta
-from pathlib import Path
-from uuid import UUID
-
-
-class ExtendedJSONEncoder(json.JSONEncoder):
-    """Encodes additional types into JSON format."""
-
-    def default(self, obj):
-        if isinstance(obj, (datetime, date)):
-            return str(obj)
-
-        if isinstance(obj, UUID):
-            return str(obj)
-
-        if isinstance(obj, timedelta):
-            return obj.total_seconds()
-
-        if isinstance(obj, enum.Enum):
-            return obj.value
-
-        if isinstance(obj, Path):
-            return str(obj)
-
-        return json.JSONEncoder.default(self, obj)
diff --git a/tests/test_json.py b/tests/test_json.py
deleted file mode 100644
index 674c914..0000000
--- a/tests/test_json.py
+++ /dev/null
@@ -1,24 +0,0 @@
-import enum
-import json
-from datetime import datetime, date, timedelta
-from pathlib import Path
-from uuid import uuid4
-
-from infrasys.utils.json import ExtendedJSONEncoder
-
-
-class Fruit(str, enum.Enum):
-    APPLE = "apple"
-    ORANGE = "orange"
-
-
-def test_json_encoder():
-    data = {
-        "datetime": datetime.now(),
-        "date": date.today(),
-        "timedelta": timedelta(hours=1),
-        "uuid": uuid4(),
-        "path": Path(".").absolute(),
-        "enum": Fruit.APPLE,
-    }
-    json.dumps(data, cls=ExtendedJSONEncoder)