Persistent issue with equate_variables

Hello everyone,

I’m returning to this topic, because I have no idea what to do anymore.

I’m trying to incorporate the equate_variables constraint in oemof 0.4.4, as it is done in this example to emulate a transmission line.

I however have multiple transmission lines going out of one bus, so my example varies slightly from the one provided… and so I am having difficulties understanding the error:

'Index \'("< Label(tag1=\'CV_EL_decentral\', tag2=\'R0000_R0020\', tag3=\'new\')>", "< Label(tag1=\'b_EL\', tag2=\'R0000\', tag3=\'\')>")\' is not valid for indexed component \'InvestmentFlow.invest\''

I have a suspicion that this is because solph thinks that the second transmission lie going out of my “R0000” bus is just a copy of my first transmission line, since I have been able to reproduce this error before for a similar case. But - in contrast to that previous case, where there literally were just two exactly identical components being fed to the model - this is just simply not the case → labelling is different, the destination of the transmission lines is different etc.

What do I do ?

Help is greatly appreciated.

Hi @moritz_reuter!

The error says that it cannot find investment for the Flow between “CV_EL_decentral/R0000_R0020/new” and “b_EL/R0000/”. To properly help you, I’d need some more context. Without, I can just suspect that you try to connect two nodes with more than one Flow. This way, you second Flow will overwrite the first one.