friendlysam.parts.Storage

class friendlysam.parts.Storage(resource, capacity=None, maxchange=None, name=None)

Simple storage model.

The storage has a volume function. It should be thought of as the volume at the beginning of a time step, such that volume(t) + accumulation[resource](t) == volume(t+1), or more exactly,

>>> s = Storage('my_resource')
>>> t = 42
>>> t_plus_1 = s.step_time(t, 1)
>>> s.accumulation['my_resource'](t) == s.volume(t_plus_1) - s.volume(t)
True

Parameters:

• resource – The resource to store.
• capacity (float, optional) – The maximum amount that can be stored. If None (the default), there is no limit.
• maxchange (float, optional) – The maxchange of the storage.
• name (str, optional) – The name of the node.

Examples

>>> from pandas import Timestamp, Timedelta
>>> battery = Storage('power', name='Battery')
>>> battery.time_unit = Timedelta('3h')
>>> t = Timestamp('2015-06-10 18:00')
>>> print(battery.accumulation['power'](t))
Battery.volume(2015-06-10 21:00:00) - Battery.volume(2015-06-10 18:00:00)

Storage.add_part(part)	Add a part to this part.
Storage.balance_constraints(index)	Balance constraints for all resources.
Storage.cluster(resource)	Get a Cluster this node is in.
Storage.find(name)	Try to find a part by name.
Storage.iter_times(start, *range_args)	A generator yielding a sequence of times.
Storage.iter_times_between(start, end)	A generator yielding all times between two points.
Storage.parts([depth, include_self])	Get contained parts, recursively.
Storage.remove_part(part)	Remove a part from this part.
Storage.set_cluster(cluster)	Add this node to a Cluster.
Storage.state_variables(index)	The only state variable is volume (index).
Storage.step_time(index, num_steps)	A function for stepping forward or backward in time.
Storage.times(start, *range_args)	Get a sequence of times.
Storage.times_between(start, end)	Get a tuple of all times between two points.
Storage.unset_cluster(cluster)	Remove from a Cluster.

Storage.accumulation	A dictionary of accumulation functions.
Storage.children	Parts in this part, excluding self.
Storage.children_and_self	Parts in this part, including self.
Storage.constraints	For defining and generating constraints.
Storage.consumption	A dictionary of consumption functions.
Storage.descendants	All children, children of children, etc, excluding self.
Storage.descendants_and_self	All children, children of children, etc, including self.
Storage.inflows	A dictionary of sets of inflow functions.
Storage.name	A name for the object.
Storage.outflows	A dictionary of sets of outflow functions.
Storage.production	A dictionary of production functions.
Storage.resource	The resource this storage stores.
Storage.resources	The set of resources this node handles.
Storage.time_unit	The time unit used in step_time().