Multi-Link usage: CHP with fixed heat-power ratio

This notebook if a demonstration of Link with multiple outputs: Combined-Heat-and-Power (CHP) with fixed heat-power ratio

For a CHP with a more complicated heat-power feasible operational area, see the power-to-gas example

This example demonstrates a Link component with more than one bus output (“bus2” in this case). In general links can have many output buses.

In this example a CHP must be heat-following because there is no other supply of heat to the bus “Frankfurt heat”.

[1]:

import pypsa, numpy as np

First tell PyPSA that links will have a 2nd bus by overriding the component_attrs. This can be done for as many buses as you need with format busi for i = 2,3,4,5,….

[2]:

override_component_attrs = pypsa.descriptors.Dict({k : v.copy() for k,v in pypsa.components.component_attrs.items()})
override_component_attrs["Link"].loc["bus2"] = ["string",np.nan,np.nan,"2nd bus","Input (optional)"]
override_component_attrs["Link"].loc["efficiency2"] = ["static or series","per unit",1.,"2nd bus efficiency","Input (optional)"]
override_component_attrs["Link"].loc["p2"] = ["series","MW",0.,"2nd bus output","Output"]

[3]:

network = pypsa.Network(override_component_attrs=override_component_attrs)

network.add("Bus", "Frankfurt", carrier="AC")
network.add("Load", "Frankfurt", bus="Frankfurt", p_set=5)


network.add("Bus", "Frankfurt heat", carrier="heat")
network.add("Load", "Frankfurt heat", bus="Frankfurt heat", p_set=3)


network.add("Bus", "Frankfurt gas", carrier="gas")
network.add("Store",
            "Frankfurt gas",
            e_initial=1e6,
            e_nom=1e6,
            bus="Frankfurt gas")

network.add("Link",
            "OCGT",
            bus0="Frankfurt gas",
            bus1="Frankfurt",
            p_nom_extendable=True,
            capital_cost=600,
            efficiency=0.4)


network.add("Link",
            "CHP",
            bus0="Frankfurt gas",
            bus1="Frankfurt",
            bus2="Frankfurt heat",
            p_nom_extendable=True,
            capital_cost=1400,
            efficiency=0.3,
            efficiency2=0.3)

[4]:

network.lopf();

INFO:pypsa.opf:Performed preliminary steps
INFO:pypsa.opf:Building pyomo model using `kirchhoff` formulation
INFO:pypsa.opf:Solving model using glpk
WARNING:pyomo.solvers:Could not locate the 'glpsol' executable, which is required for solver 'glpk'

---------------------------------------------------------------------------
ApplicationError                          Traceback (most recent call last)
/tmp/ipykernel_362/3801474310.py in <module>
----> 1 network.lopf();

~/checkouts/readthedocs.org/user_builds/pypsa-docs-staging/envs/latest/lib/python3.7/site-packages/pypsa/components.py in lopf(self, snapshots, pyomo, solver_name, solver_options, solver_logfile, formulation, keep_files, extra_functionality, multi_investment_periods, **kwargs)
    646
    647         if pyomo:
--> 648             return network_lopf(self, **args)
    649         else:
    650             return network_lopf_lowmem(self, **args)

~/checkouts/readthedocs.org/user_builds/pypsa-docs-staging/envs/latest/lib/python3.7/site-packages/pypsa/opf.py in network_lopf(network, snapshots, solver_name, solver_io, skip_pre, extra_functionality, multi_investment_periods, solver_logfile, solver_options, keep_files, formulation, ptdf_tolerance, free_memory, extra_postprocessing)
   1663                               solver_logfile=solver_logfile, solver_options=solver_options,
   1664                               keep_files=keep_files, free_memory=free_memory,
-> 1665                               extra_postprocessing=extra_postprocessing)

~/checkouts/readthedocs.org/user_builds/pypsa-docs-staging/envs/latest/lib/python3.7/site-packages/pypsa/opf.py in network_lopf_solve(network, snapshots, formulation, solver_options, solver_logfile, keep_files, free_memory, extra_postprocessing)
   1563             network.results = network.opt.solve(*args, suffixes=["dual"], keepfiles=keep_files, logfile=solver_logfile, options=solver_options)
   1564     else:
-> 1565         network.results = network.opt.solve(*args, suffixes=["dual"], keepfiles=keep_files, logfile=solver_logfile, options=solver_options)
   1566
   1567     if logger.isEnabledFor(logging.INFO):

~/checkouts/readthedocs.org/user_builds/pypsa-docs-staging/envs/latest/lib/python3.7/site-packages/pyomo/opt/base/solvers.py in solve(self, *args, **kwds)
    510         """ Solve the problem """
    511
--> 512         self.available(exception_flag=True)
    513         #
    514         # If the inputs are models, then validate that they have been

~/checkouts/readthedocs.org/user_builds/pypsa-docs-staging/envs/latest/lib/python3.7/site-packages/pyomo/opt/solver/shellcmd.py in available(self, exception_flag)
    123             if exception_flag:
    124                 msg = "No executable found for solver '%s'"
--> 125                 raise ApplicationError(msg % self.name)
    126             return False
    127         return True

ApplicationError: No executable found for solver 'glpk'

[5]:

network.loads_t.p

[5]:


now

[6]:

network.links_t.p0

[6]:


now

[7]:

network.links_t.p1

[7]:


now

[8]:

network.links_t.p2

[8]:


now