I assume the costs you plotted are totals taken from the annualized costs? I would look at the results in more detail and see which processes/commodities are causing the costs. In that way one would be able to see where such investment costs and variable O&M costs in the Base year are coming from, and then the modeller should be able to understand why that is so, and if there is something wrong about it, to correct the model accordingly.
High costs in the Base year often suggest bad calibration and/or dummy imports, but you can only find out where the costs occur by looking at those detailed costs.
High costs in the Base year often suggest bad calibration and/or dummy imports, but you can only find out where the costs occur by looking at those detailed costs.