Implement DAC properly with electricity and heat demand

Before it just had a fixed marginal cost. Now it uses DEA assumptions
for heat, electricity and capital costs.

This necessitates locating it somewhere concrete. Heat is taken from
urban central or decentral buses.

scripts/prepare_sector_network.py

@@ -208,17 +208,26 @@ def add_co2_tracking(n):
                efficiency=1.,
                p_nom_extendable=True)
 
-    if options['dac']:
+def add_dac(n):
-        #direct air capture consumes electricity to take CO2 from the air to the underground store
+
-        #TODO do with cost from Breyer - later use elec and heat and capital cost
+    heat_buses = n.buses.index[n.buses.carrier.isin(["urban central heat",
-        n.madd("Link",["DAC"],
+                                                     "services urban decentral heat"])]
-               bus0="co2 atmosphere",
+    locations = n.buses.location[heat_buses]
-               bus1="co2 stored",
+
-               carrier="DAC",
+    n.madd("Link",
-               marginal_cost=75.,
+           locations,
-               efficiency=1.,
+           suffix=" DAC",
-               p_nom_extendable=True,
+           bus0="co2 atmosphere",
-               lifetime=costs.at['direct air capture','lifetime'])
+           bus1="co2 stored",
+           bus2=locations.values,
+           bus3=heat_buses,
+           carrier="DAC",
+           capital_cost=costs.at['direct air capture','fixed'],
+           efficiency=1.,
+           efficiency2=-(costs.at['direct air capture','electricity-input'] + costs.at['direct air capture','compression-electricity-input']),
+           efficiency3=-(costs.at['direct air capture','heat-input'] - costs.at['direct air capture','compression-heat-output']),
+           p_nom_extendable=True,
+           lifetime=costs.at['direct air capture','lifetime'])
 
 
 def add_co2limit(n, Nyears=1.,limit=0.):
@@ -1896,6 +1905,9 @@ if __name__ == "__main__":
     if "I" in opts and "H" in opts:
         add_waste_heat(n)
 
+    if options['dac']:
+        add_dac(n)
+
     if "decentral" in opts:
         decentral(n)