diff --git a/.github/actions/before-script/action.yml b/.github/actions/before-script/action.yml
index 5d8ff1a..8ecfb55 100644
--- a/.github/actions/before-script/action.yml
+++ b/.github/actions/before-script/action.yml
@@ -23,23 +23,20 @@ runs:
         poetry install
         cd "$GITHUB_WORKSPACE"
 
-        git clone https://gitlab.sintef.no/harald.svendsen/timeseries.git
-        cd "$GITHUB_WORKSPACE/timeseries"
+        cd "$GITHUB_WORKSPACE/submodules/wind_power_timeseries"
         poetry install
         cd "$GITHUB_WORKSPACE"
 
-        git clone https://github.com/iDesignRES/Tecnalia.git
-        cd "$GITHUB_WORKSPACE/Tecnalia/examples/pv_power_plants"
+        cd "$GITHUB_WORKSPACE/submodules/Tecnalia/examples/pv_power_plants"
         poetry install
-        cd "$GITHUB_WORKSPACE/Tecnalia/examples/building_energy_process"
+        cd "$GITHUB_WORKSPACE/submodules/Tecnalia/examples/building_energy_process"
         poetry install
         cd "$GITHUB_WORKSPACE"
 
-        git clone https://github.com/iDesignRES/CHP_modelling.git
-        cd "$GITHUB_WORKSPACE/CHP_modelling"
+        cd "$GITHUB_WORKSPACE/submodules/CHP_modelling"
         mkdir build
         cd build
         cmake ..
         make
         cd "$GITHUB_WORKSPACE"
-      shell: bash
\ No newline at end of file
+      shell: bash
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 18597ca..fea9768 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -22,6 +22,8 @@ jobs:
             arch: x64
     steps:
       - uses: actions/checkout@v4
+        with:
+          submodules: true  # Fetch the submodules
       - uses: ./.github/actions/before-script
       - uses: julia-actions/setup-julia@v2
         with:
diff --git a/.github/workflows/documentation.yml b/.github/workflows/documentation.yml
index 212f916..d5c701f 100644
--- a/.github/workflows/documentation.yml
+++ b/.github/workflows/documentation.yml
@@ -10,6 +10,8 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
+        with:
+          submodules: true  # Fetch the submodules
       - uses: ./.github/actions/before-script
       - uses: julia-actions/setup-julia@latest
         with:
diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000..c721335
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,9 @@
+[submodule "submodules/Tecnalia"]
+	path = submodules/Tecnalia
+	url = https://github.com/iDesignRES/Tecnalia.git
+[submodule "submodules/wind_power_timeseries"]
+	path = submodules/wind_power_timeseries
+	url = https://gitlab.sintef.no/harald.svendsen/wind_power_timeseries.git
+[submodule "submodules/CHP_modelling"]
+	path = submodules/CHP_modelling
+	url = https://github.com/iDesignRES/CHP_modelling.git
diff --git a/submodules/CHP_modelling b/submodules/CHP_modelling
new file mode 160000
index 0000000..6b0f0f9
--- /dev/null
+++ b/submodules/CHP_modelling
@@ -0,0 +1 @@
+Subproject commit 6b0f0f98bb9cf366f29c0fb8146f1f4babe28965
diff --git a/submodules/Tecnalia b/submodules/Tecnalia
new file mode 160000
index 0000000..3319330
--- /dev/null
+++ b/submodules/Tecnalia
@@ -0,0 +1 @@
+Subproject commit 33193307f8ae55e6d0429428e464954ee6f80f0d
diff --git a/submodules/wind_power_timeseries b/submodules/wind_power_timeseries
new file mode 160000
index 0000000..6511abb
--- /dev/null
+++ b/submodules/wind_power_timeseries
@@ -0,0 +1 @@
+Subproject commit 6511abb340cec4e0630e9f8b3e2bbd6d4096d841
diff --git a/test/test_CSPandPV.jl b/test/test_CSPandPV.jl
index d803817..1cc5a6f 100644
--- a/test/test_CSPandPV.jl
+++ b/test/test_CSPandPV.jl
@@ -19,11 +19,8 @@ using Dates
     T = TwoLevel(sp_duration, operational_periods; op_per_strat = 8760.0)
 
     # Load paths to default Buildings process and authentication files
-    project_path = joinpath(@__DIR__, "..", "Tecnalia")
-    if !isdir(project_path)
-        project_path = joinpath(@__DIR__, "..", "..", "Tecnalia")
-    end
-    project_path = joinpath(project_path, "examples", "pv_power_plants")
+    project_path =
+        joinpath(@__DIR__, "..", "submodules", "Tecnalia", "examples", "pv_power_plants")
     path_to_auth_file_csp_pv = joinpath(project_path, "auth.json")
     auth_pay_load_csp_pv = JSON.parsefile(path_to_auth_file_csp_pv)
 
diff --git a/test/test_bioCHP.jl b/test/test_bioCHP.jl
index 78eb483..b394980 100644
--- a/test/test_bioCHP.jl
+++ b/test/test_bioCHP.jl
@@ -40,11 +40,15 @@ using EnergyModelsHeat
         BioBirchStem => 0.3,
         BioSpruceTB => 0.4,
     )
-    libpath = joinpath(@__DIR__, "..", "CHP_modelling")
-    if !isdir(libpath)
-        libpath = joinpath(@__DIR__, "..", "..", "CHP_modelling")
-    end
-    libpath = joinpath(libpath, "build", "lib", "libbioCHP_wrapper.so")
+    libpath = joinpath(
+        @__DIR__,
+        "..",
+        "submodules",
+        "CHP_modelling",
+        "build",
+        "lib",
+        "libbioCHP_wrapper.so",
+    )
 
     bio_chp = BioCHP(
         "Bio CHP plant",
diff --git a/test/test_buildings.jl b/test/test_buildings.jl
index 094458f..7500d9a 100644
--- a/test/test_buildings.jl
+++ b/test/test_buildings.jl
@@ -28,11 +28,14 @@ using Dates
     T = TwoLevel(sp_duration, operational_periods; op_per_strat = 8760.0)
 
     # Load paths to default Buildings process and authentication files
-    project_path = joinpath(@__DIR__, "..", "Tecnalia")
-    if !isdir(project_path)
-        project_path = joinpath(@__DIR__, "..", "..", "Tecnalia")
-    end
-    project_path = joinpath(project_path, "examples", "building_energy_process")
+    project_path = joinpath(
+        @__DIR__,
+        "..",
+        "submodules",
+        "Tecnalia",
+        "examples",
+        "building_energy_process",
+    )
     path_to_auth_file_buildings = joinpath(project_path, "auth.json")
     auth_pay_load_buildings = JSON.parsefile(path_to_auth_file_buildings)