Link with several inputs (Modeling industry processes)

[gktho...@gmail.com]

Hi guys,

I am currently looking into how to depict industrial processes with pypsa. I want to have several processes (and thereby energy flows), which need to be combined to generate one single output. These processes have a fixed ratio of energy consumption, which is proportional to the total output. So per ton of steel produced through a blast furnace I have x MWh of useful energy which is used for sintering and pellet making, y MWh for the blast furnace and so on.

I was thinking that a link with several inputs but only one output would be fitting. However, I only found a link with several outputs, as in the example script with the CHP and a fixed heat to power ratio. Therefore the options I see so far are these:

• Link with several outputs, p_min_pu=-1 and p_max_pu = 0
• Several links for each flow
  • Fix the flow ratios between links through additional constraints (extra_functionality)
• Link with several inputs? Can be done through the override_components function, or is a link defined in a way that it can only have one input?

Am I missing something? I am super thankful for additional suggestions on how to do this elegantly!

Best,
Georg

[Fabian Neumann]

Hi Georg,

we normally follow the flow reversal technique you mention for
single-output-multiple-input links (p_min_pu=-1 and p_max_pu=0).

There's a short section hidden in the PyPSA documentation.

https://pypsa.readthedocs.io/en/latest/components.html#link-with-multiple-outputs-or-inputs

I think this is the most elegant way currently, but it still can be a
head twist.

Best wishes,

Fabian

On 15/12/2020 11:01, gktho...@gmail.com wrote:
>
> Hi guys,
>
> I am currently looking into how to depict industrial processes with
> pypsa. I want to have several processes (and thereby energy flows),
> which need to be combined to generate one single output. These processes
> have a fixed ratio of energy consumption, which is proportional to the
> total output. So per ton of steel produced through a blast furnace I
> have x MWh of useful energy which is used for sintering and pellet
> making, y MWh for the blast furnace and so on.
> I was thinking that a link with several inputs but only one output would
> be fitting. However, I only found a link with several outputs, as in the
> example script with the CHP and a fixed heat to power ratio. Therefore
> the options I see so far are these:
>

> * Link with several outputs, p_min_pu=-1 and p_max_pu = 0
> * Several links for each flow
> o Fix the flow ratios between links through additional constraints
> (extra_functionality)
> * Link with several inputs? Can be done through the

> override_components function, or is a link defined in a way that it
> can only have one input?
>
> Am I missing something? I am super thankful for additional suggestions
> on how to do this elegantly!
>
> Best,
> Georg
>

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[Tom Brown]

Hi Georg,

Sorry for the reply latency, but the best way to model several inputs is
to model them as outputs with negative efficiency. This is the way we've
been doing it in PyPSA-Eur-Sec.

I've just updated the documentation to reflect this advice:

https://pypsa.readthedocs.io/en/latest/components.html#components-links-multiple-outputs

(may need to reload).

As an example, see the Fischer-Tropsch process in this example:

https://github.com/PyPSA/PyPSA/blob/master/examples/notebooks/biomass-synthetic-fuels-carbon-management.ipynb

The main input is hydrogen, then there is an output connected to carbon
dioxide with negative efficiency (-1), so that the link takes carbon
dioxide for each unit of hydrogen, then produces diesel as another output.

The outputs are always proportional to the main input at bus0.

Best wishes,

Tom

On 15/12/2020 11:01, gktho...@gmail.com wrote:
>

> Hi guys,
>
> I am currently looking into how to depict industrial processes with
> pypsa. I want to have several processes (and thereby energy flows),
> which need to be combined to generate one single output. These processes
> have a fixed ratio of energy consumption, which is proportional to the
> total output. So per ton of steel produced through a blast furnace I
> have x MWh of useful energy which is used for sintering and pellet
> making, y MWh for the blast furnace and so on.
> I was thinking that a link with several inputs but only one output would
> be fitting. However, I only found a link with several outputs, as in the
> example script with the CHP and a fixed heat to power ratio. Therefore
> the options I see so far are these:
>

> * Link with several outputs, p_min_pu=-1 and p_max_pu = 0
> * Several links for each flow
> o Fix the flow ratios between links through additional constraints
> (extra_functionality)
> * Link with several inputs? Can be done through the

> override_components function, or is a link defined in a way that it
> can only have one input?
>
> Am I missing something? I am super thankful for additional suggestions
> on how to do this elegantly!
>
> Best,
> Georg
>

> --
> You received this message because you are subscribed to the Google
> Groups "pypsa" group.
> To unsubscribe from this group and stop receiving emails from it, send
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> To view this discussion on the web, visit
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> <https://groups.google.com/d/msgid/pypsa/52c321c7-9c6a-4242-9fea-ab0b7b66030fn%40googlegroups.com?utm_medium=email&utm_source=footer>.

--
Karlsruhe Institute of Technology (KIT)
Institute for Automation and Applied Informatics (IAI)

Tom Brown (he/him)
Research Group Leader, Energy System Modelling

Phone: +49 721 608 25737
Fax: +49 721 608 22602
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