13-08-2019, 01:37 AM

I've been trying to recreate the objective function from the TIMES outputs. My question is about the interpretation of the Cost_Fom outputs.

The model base year is 2010 and the periods are 2010, 2011, 2012, 2013-2017, 2018-2022, 2023-2027.

The technology I'm using to illustrate my queries has TLIFE=ELIFE=12 and ILED=0. I'm looking at investments in 2011, 2012 and 2015 vintages. See the attached workbook for details (I cant see how to paste images or tables here).

The 2011 vintage covers the 2011, 2012, 2015 and 2020 periods exactly, and multiplying undiscounted levelised Cost_Fom by TIME_NPV gives the objective function cost.

The 2012 vintage covers the 2012, 2015 and 2020 periods in full, and the first year of the 2025 period. Yet no Cost_Fom (nor Cost_Inv) is output for the 2025 period (marked by an empty red box on the output table). Is there a reason why?

The 2015 vintage covers the 2015 and 2020 periods in full, and the two years of the 2025 period. The output Cost_Fom in the 2025 period (coloured red) is 40% of the Cost_Fom in the other periods, presumably as the technology is active for only 40% of the period. This suggests that multiplying all of the Cost_Fom values by TIME_NPV would give the discounted objective function cost. However, this is incorrect. In reality, it is necessary to consider only the discount rates in first two years of the 2025 period, meaning the TIME_NPV multiplier for this technology in this period is 3.14 (coloured red) rather than 2.99. I find the current outputs misleading, as they suggest that the discounted cost can be calculated by multiplying by TIME_NPV in the final period in the same way as for the earlier periods, when this is not the case.

One option would be to output the same undiscounted annual cost in the final period as for the earlier periods. This would at least be clear about the meaning of the data. The disadvantage would be an even more estimate of the objective function calculation from the output data.

A better option might be to output the undiscounted cost that when calculated by the TIME_NPV factor would give the objective function cost (i.e. 1931 instead of 1836, in this case).

I'm interested to hear your thoughts. As things stand, calculating the contribution to the objective function from each technology appears extremely time-consuming if it has to be carried out on a process-by-process basis.

The model base year is 2010 and the periods are 2010, 2011, 2012, 2013-2017, 2018-2022, 2023-2027.

The technology I'm using to illustrate my queries has TLIFE=ELIFE=12 and ILED=0. I'm looking at investments in 2011, 2012 and 2015 vintages. See the attached workbook for details (I cant see how to paste images or tables here).

The 2011 vintage covers the 2011, 2012, 2015 and 2020 periods exactly, and multiplying undiscounted levelised Cost_Fom by TIME_NPV gives the objective function cost.

The 2012 vintage covers the 2012, 2015 and 2020 periods in full, and the first year of the 2025 period. Yet no Cost_Fom (nor Cost_Inv) is output for the 2025 period (marked by an empty red box on the output table). Is there a reason why?

The 2015 vintage covers the 2015 and 2020 periods in full, and the two years of the 2025 period. The output Cost_Fom in the 2025 period (coloured red) is 40% of the Cost_Fom in the other periods, presumably as the technology is active for only 40% of the period. This suggests that multiplying all of the Cost_Fom values by TIME_NPV would give the discounted objective function cost. However, this is incorrect. In reality, it is necessary to consider only the discount rates in first two years of the 2025 period, meaning the TIME_NPV multiplier for this technology in this period is 3.14 (coloured red) rather than 2.99. I find the current outputs misleading, as they suggest that the discounted cost can be calculated by multiplying by TIME_NPV in the final period in the same way as for the earlier periods, when this is not the case.

One option would be to output the same undiscounted annual cost in the final period as for the earlier periods. This would at least be clear about the meaning of the data. The disadvantage would be an even more estimate of the objective function calculation from the output data.

A better option might be to output the undiscounted cost that when calculated by the TIME_NPV factor would give the objective function cost (i.e. 1931 instead of 1836, in this case).

I'm interested to hear your thoughts. As things stand, calculating the contribution to the objective function from each technology appears extremely time-consuming if it has to be carried out on a process-by-process basis.