Merge pull request #70 from oemof/feature/constraint-facade

Load constraints from datapackage

docs/usage.rst

@@ -114,7 +114,7 @@ We adhere to the frictionless `(tabular) datapackage standard  <https://friction
 On top of that structure we add our own logic. We require at least two things:
 
 	1. A directory named *data* containing at least one sub-folder called *elements*
-	(optionally it may contain a directory *sequences* and *geometries*. Of
+	(optionally it may contain a directory *sequences*, *geometries* and/or *constraints*. Of
 	course you may add any other directory, data or other information.)
 
 	2. A valid meta-data `.json` file for the datapackage
@@ -143,8 +143,10 @@ resources are equivalent to parameters of the energy system elements and
 sequences.
 
 To distinguish elements and sequences these two are stored in sub-directories of
-the data directory. In addition geometrical information can be stored under
-`data/geometries` in a `.geojson` format. To simplifiy the process of creating
+the data directory. In addition, geometrical information can be stored under
+`data/geometries` in a `.geojson` format. An optional subdirectory `data/constraints`
+can hold data describing global constraints.
+To simplifiy the process of creating
 and processing a datapackage you may
 also use the funtionalities of the :py:mod:`~oemof.tabular.datapackage`
 

src/oemof/tabular/constraint_facades.py

@@ -0,0 +1,42 @@
+import abc
+from dataclasses import dataclass
+
+from oemof.solph.constraints.integral_limit import generic_integral_limit
+
+
+class ConstraintFacade(abc.ABC):
+    def build_constraint(self):
+        pass
+
+
+@dataclass
+class GenericIntegralLimit(ConstraintFacade):
+    name: str
+    type: str
+    limit: float
+    keyword: str = "emission_factor"
+
+    def build_constraint(self, model):
+        # to use the constraints in oemof.solph, we need to pass the model.
+
+        # check if there are flows with key
+        flows = {}
+        for (i, o) in model.flows:
+            if hasattr(model.flows[i, o], self.keyword):
+                flows[(i, o)] = model.flows[i, o]
+
+        if not flows:
+            raise Warning(f"No flows with keyword {self.keyword}")
+        else:
+            print(
+                f"These flows will contribute to the "
+                f"emission constraint {flows.keys()}"
+            )
+
+        # add constraint to the model
+        generic_integral_limit(
+            model, keyword=self.keyword, flows=flows, limit=self.limit
+        )
+
+
+CONSTRAINT_TYPE_MAP = {"generic_integral_limit": GenericIntegralLimit}

src/oemof/tabular/datapackage/__init__.py

@@ -1,6 +1,9 @@
 from oemof.network.energy_system import EnergySystem
+from oemof.solph import Model
 
 from . import building  # noqa F401
-from .reading import deserialize_energy_system
+from .reading import deserialize_constraints, deserialize_energy_system
 
 EnergySystem.from_datapackage = classmethod(deserialize_energy_system)
+
+Model.add_constraints_from_datapackage = deserialize_constraints

src/oemof/tabular/datapackage/building.py

@@ -174,6 +174,7 @@ def infer_metadata(
             )
             p.add_resource(r.descriptor)
 
+    # create meta data resources geometries
     if not os.path.exists("data/geometries"):
         print(
             "No geometries path found in directory {}. Skipping...".format(
@@ -192,6 +193,25 @@ def infer_metadata(
             )
             p.add_resource(r.descriptor)
 
+    # create meta data resources constraints
+    if not os.path.exists("data/constraints"):
+        print(
+            "No constraints path found in directory {}. Skipping...".format(
+                os.getcwd()
+            )
+        )
+    else:
+        for f in os.listdir("data/constraints"):
+            r = Resource(
+                {"path": str(pathlib.PurePosixPath("data", "constraints", f))}
+            )
+            r.infer()
+            r.commit()
+            r.save(
+                pathlib.PurePosixPath("resources", f.replace(".csv", ".json"))
+            )
+            p.add_resource(r.descriptor)
+
     p.commit()
     p.save(metadata_filename)
 

src/oemof/tabular/datapackage/reading.py

@@ -481,3 +481,40 @@ def find(n, d):
 
     else:
         raise ValueError("Timeindices in resources differ!")
+
+
+def deserialize_constraints(model, path, constraint_type_map=None):
+    if constraint_type_map is None:
+        constraint_type_map = {}
+
+    def listify(x, n=None):
+        return (
+            x if isinstance(x, list) else repeat(x) if not n else repeat(x, n)
+        )
+
+    package = dp.Package(path)
+
+    # read all resources in data/constraints
+    resources = []
+    for r in package.resources:
+        if all(
+            re.match(r"^data/constraints/.*$", p)
+            for p in listify(r.descriptor["path"], 1)
+        ):
+            resources.append(r)
+
+    for resource in resources:
+
+        resource_data = resource.read(keyed=True, relations=True)
+
+        for rw in resource_data:
+            constraint_type = rw["type"]
+
+            constraint_facade = constraint_type_map[constraint_type]
+
+            constraint = constraint_facade(**rw)
+
+            # build constraint for each facade
+            constraint.build_constraint(model)
+
+    # return model

src/oemof/tabular/examples/datapackages/emission_constraint/README.md

@@ -0,0 +1,5 @@
+# Emission constraint example for oemof-tabular
+
+Run `scripts/infer.py` from the datapackage root directory to add the
+meta data file `datapackage.json` after updating the resources of the
+datapackage.

src/oemof/tabular/examples/datapackages/emission_constraint/data/constraints/emission_constraint.csv

@@ -0,0 +1,2 @@
+name;type;limit;keyword
+constraint0;generic_integral_limit;1000;emission_factor

src/oemof/tabular/examples/datapackages/emission_constraint/data/elements/bus.csv

@@ -0,0 +1,2 @@
+name;type;balanced
+bus-electricity;bus;true

src/oemof/tabular/examples/datapackages/emission_constraint/data/elements/dispatchable.csv

@@ -0,0 +1,4 @@
+name;type;carrier;tech;capacity;bus;marginal_cost;profile;output_parameters
+gas;dispatchable;gas;gt;1000;bus-electricity;40;1;{"emission_factor": 10}
+coal;dispatchable;coal;st;1000;bus-electricity;40;1;{"emission_factor": 20}
+lignite;dispatchable;lignite;st;500;bus-electricity;20;1;{"emission_factor": 30}

src/oemof/tabular/examples/datapackages/emission_constraint/data/elements/excess.csv

@@ -0,0 +1,2 @@
+name;type;bus
+electricity-excess;excess;bus-electricity

src/oemof/tabular/examples/datapackages/emission_constraint/data/elements/load.csv

@@ -0,0 +1,2 @@
+name;amount;profile;type;bus
+electricity-demand;5000;electricity-load-profile;load;bus-electricity

src/oemof/tabular/examples/datapackages/emission_constraint/data/elements/storage.csv

@@ -0,0 +1,2 @@
+name,carrier,tech,storage_capacity,capacity,capacity_cost,storage_capacity_initial,type,bus
+el-storage,lithium,battery,100,10,10,0.5,storage,bus-electricity

src/oemof/tabular/examples/datapackages/emission_constraint/data/elements/volatile.csv

@@ -0,0 +1,2 @@
+name;type;carrier;tech;capacity;capacity_cost;bus;marginal_cost;profile;output_parameters
+wind;volatile;wind;onshore;50;;bus-electricity;0;wind-profile;{}

src/oemof/tabular/examples/datapackages/emission_constraint/data/sequences/load_profile.csv

@@ -0,0 +1,4 @@
+timeindex,electricity-load-profile
+2011-01-01T00:00:00Z,0.000745659236
+2011-01-01T01:00:00Z,0.000709651546
+2011-01-01T02:00:00Z,0.00068564642

src/oemof/tabular/examples/datapackages/emission_constraint/data/sequences/volatile_profile.csv

@@ -0,0 +1,4 @@
+timeindex,wind-profile
+2011-01-01T00:00:00Z,0.147532
+2011-01-01T01:00:00Z,0.184181
+2011-01-01T02:00:00Z,0.223937