diff --git a/ph_units/unit_types/energy.py b/ph_units/unit_types/energy.py
index f96664e..4e62666 100644
--- a/ph_units/unit_types/energy.py
+++ b/ph_units/unit_types/energy.py
@@ -8,14 +8,16 @@ class WattHour(Base_UnitType):
     """Wh"""
 
     __symbol__ = "WH"
-    __aliases__ = []
+    __aliases__ = ["WATT-HOUR", "WATT-HOURS", "WHR"]
     __factors__ = {
-        "WH": "{}*1",
-        "KWH": "{}*0.001",
         "BTU": "{}*3.41214",
         "KBTU": "{}*0.00341214",
-        "MJ": "{}*0.0036",
+        "WH": "{}*1",
+        "KWH": "{}*0.001",
+        "J": "{}*3600",
         "KJ": "{}*3.6",
+        "MJ": "{}*0.0036",
+        "GJ": "{}*0.0000036",
     }
 
 
@@ -23,14 +25,16 @@ class KiloWattHour(Base_UnitType):
     """KWH"""
 
     __symbol__ = "KWH"
-    __aliases__ = ["KWH/YR", "KWH/A", "KWH/M", "KWH/MONTH"]
+    __aliases__ = ["KWHR", "KWH/YR", "KWH/A", "KWH/M", "KWH/MONTH"]
     __factors__ = {
-        "WH": "{}*1000",
-        "KWH": "{}*1",
         "BTU": "{}*3412.14",
         "KBTU": "{}*3.41214",
-        "MJ": "{}*3.6",
+        "WH": "{}*1000",
+        "KWH": "{}*1",
+        "J": "{}*3600000",
         "KJ": "{}*3600",
+        "MJ": "{}*3.6",
+        "GJ": "{}*0.0036",
     }
 
 
@@ -40,12 +44,14 @@ class BTU(Base_UnitType):
     __symbol__ = "BTU"
     __aliases__ = []
     __factors__ = {
-        "WH": "{}*0.293071",
-        "KWH": "{}*0.000293071",
         "BTU": "{}*1",
         "KBTU": "{}*0.001",
-        "MJ": "{}*0.00105506",
+        "WH": "{}*0.293071",
+        "KWH": "{}*0.000293071",
+        "J": "{}*1055.06",
         "KJ": "{}*1.05506",
+        "MJ": "{}*0.00105506",
+        "GJ": "{}*0.00000105506",
     }
 
 
@@ -55,27 +61,31 @@ class KiloBTU(Base_UnitType):
     __symbol__ = "KBTU"
     __aliases__ = []
     __factors__ = {
-        "WH": "{}*293.071",
-        "KWH": "{}*0.293071",
         "BTU": "{}*1000",
         "KBTU": "{}*1",
-        "MJ": "{}*1.05506",
+        "WH": "{}*293.071",
+        "KWH": "{}*0.293071",
+        "J": "{}*1055060",
         "KJ": "{}*1055.06",
+        "MJ": "{}*1.05506",
+        "GJ": "{}*0.00105506",
     }
 
 
-class MegaJoule(Base_UnitType):
-    """MJ"""
+class Joule(Base_UnitType):
+    """J"""
 
-    __symbol__ = "MJ"
-    __aliases__ = []
+    __symbol__ = "J"
+    __aliases__ = ["JOULE"]
     __factors__ = {
-        "WH": "{}*277.778",
-        "KWH": "{}*0.277778",
-        "BTU": "{}*947.817",
-        "KBTU": "{}*0.947817",
-        "MJ": "{}*1",
-        "KJ": "{}*1000",
+        "BTU": "{}*0.000947817",
+        "KBTU": "{}*0.000000947817",
+        "WH": "{}*0.000277778",
+        "KWH": "{}*0.00000027778 ",
+        "J": "{}*1",
+        "KJ": "{}*0.001",
+        "MJ": "{}*0.000001",
+        "GJ": "{}*0.000000001",
     }
 
 
@@ -83,14 +93,50 @@ class KiloJoule(Base_UnitType):
     """KJ"""
 
     __symbol__ = "KJ"
-    __aliases__ = []
+    __aliases__ = ["KILOJOULE"]
     __factors__ = {
-        "WH": "{}*0.277778",
-        "KWH": "{}*0.000277778",
         "BTU": "{}*0.947817",
         "KBTU": "{}*0.000947817",
-        "MJ": "{}*0.001",
+        "WH": "{}*0.277778",
+        "KWH": "{}*0.000277778",
+        "J": "{}*1000",
         "KJ": "{}*1",
+        "MJ": "{}*0.001",
+        "GJ": "{}*0.000001",
+    }
+
+
+class MegaJoule(Base_UnitType):
+    """MJ"""
+
+    __symbol__ = "MJ"
+    __aliases__ = ["MEGAJOULE"]
+    __factors__ = {
+        "BTU": "{}*947.817",
+        "KBTU": "{}*0.947817",
+        "WH": "{}*277.778",
+        "KWH": "{}*0.277778",
+        "J": "{}*1000000",
+        "KJ": "{}*1000",
+        "MJ": "{}*1",
+        "GJ": "{}*0.001",
+    }
+
+
+class GigaJoule(Base_UnitType):
+    """GJ"""
+
+    __symbol__ = "GJ"
+    __aliases__ = ["GIGAJOULE"]
+    __factors__ = {
+        "BTU": "{}*947817.120313",
+        "KBTU": "{}*947.817120313",
+        "WH": "{}*277777.778",
+        "KWH": "{}*277.778",
+        "J": "{}*1000000000",
+        "KJ": "{}*1000000",
+        "MJ": "{}*1000",
+        "GJ": "{}*1",
     }
 
 
diff --git a/tests/test_energy.py b/tests/test_energy.py
index ab710cd..64c70f7 100644
--- a/tests/test_energy.py
+++ b/tests/test_energy.py
@@ -57,57 +57,91 @@ def test_Btu_foot_squared():
 
 
 def test_wh():
-    assert convert(1, "WH", "WH") == 1
     assert convert(1, "WH", "BTU") == pytest.approx(3.41214)
-    assert convert(1, "WH", "KWH") == 0.001
     assert convert(1, "WH", "KBTU") == pytest.approx(0.003412141633)
-    assert convert(1, "WH", "MJ") == pytest.approx(0.0036)
+    assert convert(1, "WH", "WH") == 1
+    assert convert(1, "WH", "KWH") == 0.001
+    assert convert(1, "WH", "J") == 3600
     assert convert(1, "WH", "KJ") == pytest.approx(3.6)
+    assert convert(1, "WH", "MJ") == pytest.approx(0.0036)
+    assert convert(1, "WH", "GJ") == pytest.approx(0.0000036)
 
 
 def test_KWH():
-    assert convert(1, "KWH", "WH") == 1000
     assert convert(1, "KWH", "BTU") == pytest.approx(3412.141633)
-    assert convert(1, "KWH", "KWH") == 1
     assert convert(1, "KWH", "KBTU") == pytest.approx(3.412141633)
-    assert convert(1, "KWH", "MJ") == pytest.approx(3.6)
+    assert convert(1, "KWH", "WH") == 1000
+    assert convert(1, "KWH", "KWH") == 1
+    assert convert(1, "KWH", "J") == pytest.approx(3600000)
     assert convert(1, "KWH", "KJ") == pytest.approx(3600)
+    assert convert(1, "KWH", "MJ") == pytest.approx(3.6)
+    assert convert(1, "KWH", "GJ") == pytest.approx(0.0036)
 
 
 def test_BTU():
-    assert convert(1, "BTU", "WH") == pytest.approx(0.293071)
     assert convert(1, "BTU", "BTU") == 1
-    assert convert(1, "BTU", "KWH") == pytest.approx(0.000293071)
     assert convert(1, "BTU", "KBTU") == pytest.approx(0.001)
-    assert convert(1, "BTU", "MJ") == pytest.approx(0.00105506)
+    assert convert(1, "BTU", "WH") == pytest.approx(0.293071)
+    assert convert(1, "BTU", "KWH") == pytest.approx(0.000293071)
+    assert convert(1, "BTU", "J") == pytest.approx(1055.06)
     assert convert(1, "BTU", "KJ") == pytest.approx(1.05506)
+    assert convert(1, "BTU", "MJ") == pytest.approx(0.00105506)
+    assert convert(1, "BTU", "GJ") == pytest.approx(0.00000105506)
 
 
 def test_KBTU():
-    assert convert(1, "KBTU", "WH") == pytest.approx(293.071)
     assert convert(1, "KBTU", "BTU") == 1000
-    assert convert(1, "KBTU", "KWH") == pytest.approx(0.293071)
     assert convert(1, "KBTU", "KBTU") == 1
-    assert convert(1, "KBTU", "MJ") == pytest.approx(1.05506)
+    assert convert(1, "KBTU", "WH") == pytest.approx(293.071)
+    assert convert(1, "KBTU", "KWH") == pytest.approx(0.293071)
+    assert convert(1, "KBTU", "J") == pytest.approx(1055060)
     assert convert(1, "KBTU", "KJ") == pytest.approx(1055.06)
+    assert convert(1, "KBTU", "MJ") == pytest.approx(1.05506)
+    assert convert(1, "KBTU", "GJ") == pytest.approx(0.00105506)
 
 
-def test_MegaJoule():
-    assert convert(1, "MJ", "WH") == pytest.approx(277.778)
-    assert convert(1, "MJ", "BTU") == pytest.approx(947.817)
-    assert convert(1, "MJ", "KWH") == pytest.approx(0.277778)
-    assert convert(1, "MJ", "KBTU") == pytest.approx(0.947817)
-    assert convert(1, "MJ", "MJ") == 1
-    assert convert(1, "MJ", "KJ") == pytest.approx(1000)
+def test_Joule():
+    assert convert(1, "J", "BTU") == pytest.approx(0.000947817)
+    assert convert(1, "J", "KBTU") == pytest.approx(0.000000947817)
+    assert convert(1, "J", "WH") == pytest.approx(0.000277778)
+    assert convert(1, "J", "KWH") == pytest.approx(0.00000027778)
+    assert convert(1, "J", "J") == 1
+    assert convert(1, "J", "KJ") == pytest.approx(0.001)
+    assert convert(1, "J", "MJ") == pytest.approx(0.000001)
+    assert convert(1, "J", "GJ") == pytest.approx(0.000000001)
 
 
 def test_KiloJoule():
-    assert convert(1, "KJ", "WH") == pytest.approx(0.277778)
     assert convert(1, "KJ", "BTU") == pytest.approx(0.947817)
-    assert convert(1, "KJ", "KWH") == pytest.approx(0.000277778)
     assert convert(1, "KJ", "KBTU") == pytest.approx(0.000947817)
+    assert convert(1, "KJ", "WH") == pytest.approx(0.277778)
+    assert convert(1, "KJ", "KWH") == pytest.approx(0.000277778)
+    assert convert(1, "KJ", "J") == 1000
     assert convert(1, "KJ", "MJ") == pytest.approx(0.001)
     assert convert(1, "KJ", "KJ") == 1
+    assert convert(1, "KJ", "GJ") == pytest.approx(0.000001)
+
+
+def test_MegaJoule():
+    assert convert(1, "MJ", "BTU") == pytest.approx(947.817)
+    assert convert(1, "MJ", "KBTU") == pytest.approx(0.947817)
+    assert convert(1, "MJ", "WH") == pytest.approx(277.778)
+    assert convert(1, "MJ", "KWH") == pytest.approx(0.277778)
+    assert convert(1, "MJ", "J") == pytest.approx(1000000)
+    assert convert(1, "MJ", "KJ") == pytest.approx(1000)
+    assert convert(1, "MJ", "MJ") == 1
+    assert convert(1, "MJ", "GJ") == pytest.approx(0.001)
+
+
+def test_GigaJoule():
+    assert convert(1, "GJ", "BTU") == pytest.approx(947817)
+    assert convert(1, "GJ", "KBTU") == pytest.approx(947.817)
+    assert convert(1, "GJ", "WH") == pytest.approx(277778)
+    assert convert(1, "GJ", "KWH") == pytest.approx(277.778)
+    assert convert(1, "GJ", "J") == pytest.approx(1000000000)
+    assert convert(1, "GJ", "KJ") == pytest.approx(1000000)
+    assert convert(1, "GJ", "MJ") == pytest.approx(1000)
+    assert convert(1, "GJ", "GJ") == 1
 
 
 def test_MegaJoule_per_m3_DegreeKelvin():