heat pump Electricity input capacity in node file should be updated when efficiency is updated

[kaskranenburgQ]

At the moment, when the efficiency of Heat Pumps is updated, the electrical input capacity of the heatpump is stays equal while the output capacity is updated.

This can be seen in the differences of deficit in heating demand between the following scenario's:

-National Leadership Here the yearly deficit is 5.8 PJ -[National Leadership -- efficiency increase}(https://energytransitionmodel.com/saved_scenarios/17354) Here the yearly deficit is 4.4 PJ

The only change between the scenario's is that the efficiency of the air heat pump is set 20% higher in the second scenario. This indicates that the change in deficit can only be explained by a higher heat output capacity as caused by the higher efficiency.

The heat output capacity in the node file is not updated by this slider, since the efficiency update is done via fever.

There are two routes that we can take:

1. The user sets an output capacity for the heatpump for buildings, then sets the efficiency of the heatpump, and with that the electric input capacity is lowered, this is then updated in the node file.

At the moment, such an input does not exist. Users can only set the input capacity for heat pumps in the housing sector. If we were to do this correct, all of the building heating technologies should get a slider that sets the input capacity. We would also need to change the working of the fever module. We would need to do this for all heatpumps in households and buildings.

2. We update the efficiency slider, so that the slider updates the heat output capacity in the node file and keep the rest of the modelling the same. We would need to do this for all heatpumps in households and buildings.

I feel that 1 is more logical in the modelling, but more work intensive compared to 2.

[mabijkerk]

Background Typically, in our efficiency sliders such as efficiency_buildings_space_heater_network_gas, the useable_heat conversion is changed. The heat_output_capacity however is not changed in the same input. This means that for a fixed output capacity, increasing the efficiency will lead to a lower input capacity.

Now for the heat pumps such as efficiency_buildings_space_heater_heatpump_air_water_electricity this works slightly different, since we change the base_cop and the cop_per_degree. Again the heat_output_capacity is not changed, so an increase in the slider will not affect the output capacity in the node.

However, it appears that Fever does change the heat output capacity. First, because increased efficiency leads to reduced deficits for the heat pump, which can only be explained by a higher output capacity (all else remaining equal). Second, because the Fever attribute specifying the electricity input capacity does not change. All else remaining equal, this means that the output capacity must increase. See results below for slider value of 100% and 120% in the II3050v2 National Leadership scenario:

EACH(
  V(buildings_space_heater_heatpump_air_water_electricity,heat_output_capacity),
  V(buildings_space_heater_heatpump_air_water_electricity,electricity_input_conversion),,
  V(V(buildings_space_heater_heatpump_air_water_electricity, fever),capacity)
)

[
  0.01,
  0.25439088335174515,
  {:electricity=>0.0025889967637540458},
]

[
  0.01,
  0.2135134942624405,
  {:electricity=>0.0025889967637540458},
]

Issue The issue here is that the heat output capacity seems to have been changed internally in Fever, while the node attribute does not reflect that change.

Solution Attributes should be consistent throughout the model, so Fever and ETSource should agree on the heat_output_capacity.

• [ ] Confirm with @noracato the exact workings of Fever
• [ ] Determine in general whether it's more logical to change the output conversion or the input conversion when changing the efficiency of heating technologies, and how this should affect input and output capacity (also when comparing with technologies other than heat pumps)
• [ ] Based on the todos above, either make sure the heat capacity used by Fever is in line with the node attribute (solution 1 proposed by @kaskranenburgQ) or make sure that the node attribute is in line with Fever (solution 2 proposed by @kaskranenburgQ)

For now the effect of this issue is expected to be minor: it is only relevant when querying the heat_output_capacity of heat pumps. We should pick this up at some point, but it is not urgent.