Hello community,

I’m struggling with the simulation of the following scenario in oemof and was wondering if any of you could help me with it.

I would like to make a decision, if the implementation of a technology is worthwhile. Regardless of the capacity required for supply, the capacity of the technology should be fixed. For example, the question could be: Is it worthwhile investing in a 10 kW gas heating system, at periodic costs of 100 €, or not?

If I use the following transformer for this question (ep_costs=10, minimum=0, maximum=10), the capacity is optimized (e.g. to 5.5 kW) and only for the optimized capacity costs are considered (55 €):

```
solph.Transformer(
label=’gas_heating’,
inputs={naturalgas_bus: solph.Flow(variable_costs=0.07)},
outputs={heat_bus: solph.Flow(investment=solph.Investment(ep_costs=10,
minimum=0,
maximum=10,
existing=0
))}
```

If I use again the following transformer (ep_costs=10, minimum=10, maximum=10), the correct costs (100€) will be considered, but the capacity of 10 kW will be added in any case. So, there is no investment decision:

```
solph.Transformer(
label=’gas_heating’,
inputs={naturalgas_bus: solph.Flow(variable_costs=0.07)},
outputs={heat_bus: solph.Flow(investment=solph.Investment(ep_costs=10,
minimum=10,
maximum=10,
existing=0
))}
```

Is there any possibility, to make an investment decision, so that there is only the possibility of full investment (10 kW) or no investment at all (0 kW)?

I would be very happy if someone could help me with this question. Many thanks for any help in advance!

Best regards,

Christian