Ok, below I will try to answer briefly to the new comments and questions for each case:

1) Issue with HYGNSTG_new, where capacity is the amount of storable energy.

2) I was wondering what you mean by "advanced documentation". The TIMES documentation is found at https://iea-etsap.org/index.php/documentation, so which one is "advanced documentation"? Finally, your reference to "page 27" prompted me to see if there is somewhere a documentation for the VEDA-TIMES Advanced DemoS, and I found it. Anyway, you now said that you found that there is a CAP2ACT 31.536 defined, and that now you understand.

3) Ok so it is ~FI_T, but you were already able to define NCAP_AFC, and so it seems the problem is solved?

4) Good, the PCG issue seems cleared.

5) I didn't know your storage was STS. The simplified equation holds for all other types of storage, and as you didn't give any other information, I assumed your storage is a normal timeslice storage. Look at the documentation, section 6.3.36 Equation: EQ_STGTSS/IPS, and you can see the difference in the formulation when using STS. Then you also have a positive/negative flow from/to the seasonal storage variable, which gives the seasonal storage capability.

Note also that ACT_EFF cannot be used for storage, you would need to use STG_EFF. I can see ACT_EFF defined for storage in your model (although with just a value of 1).

1) Issue with HYGNSTG_new, where capacity is the amount of storable energy.

Abi Afthab Wrote:In some years, I have Var_FIn, Var_Fout and Var_Act (extremely small values, like 0.00004). But Var_cap is not reported (Process is HYGNSTG_new). Is this possible?As I have explained earlier on this Forum and elsewhere, if the capacity is the amount of storable energy, you can have simultaneous input/output storage flows in the same timeslice without any need for capacity, because then nothing gets stored. I guess that may well explain any notable input/output flows also in your case. I looked briefly at your results for one year, and apart from the smallest tiny values the input/output values in general appeared equal to each other in the same timeslice, but I did not have time to look at it extensively. But mathematically it would be impossible to have a positive activity and no capacity. Numerically that may be possible, if either your solver is bad or your model is badly scaled. The model is solved numerically, not analytically, and therefore badly scaled models may have constraints violated by small amounts. In well-scaled models any such violations are negligibly small.

2) I was wondering what you mean by "advanced documentation". The TIMES documentation is found at https://iea-etsap.org/index.php/documentation, so which one is "advanced documentation"? Finally, your reference to "page 27" prompted me to see if there is somewhere a documentation for the VEDA-TIMES Advanced DemoS, and I found it. Anyway, you now said that you found that there is a CAP2ACT 31.536 defined, and that now you understand.

3) Ok so it is ~FI_T, but you were already able to define NCAP_AFC, and so it seems the problem is solved?

4) Good, the PCG issue seems cleared.

5) I didn't know your storage was STS. The simplified equation holds for all other types of storage, and as you didn't give any other information, I assumed your storage is a normal timeslice storage. Look at the documentation, section 6.3.36 Equation: EQ_STGTSS/IPS, and you can see the difference in the formulation when using STS. Then you also have a positive/negative flow from/to the seasonal storage variable, which gives the seasonal storage capability.

Note also that ACT_EFF cannot be used for storage, you would need to use STG_EFF. I can see ACT_EFF defined for storage in your model (although with just a value of 1).