storage-based hydro

[Antti-L]

I wonder if anyone could help me how the seasonal and day-night level storage capacity of a storage based hydro-power plant could be specified

I wonder what you mean by specifying the storage capacity. If you mean defining the amount of existing capacity, you can just define it be specifying a value for the PRC_RESID or NCAP_PASTI parameter. By default, storage capacity is interpreted in terms of the amount of energy that can be stored, but if you use NCAP_AFC(output), the capacity will be the nominal max. output capacity, like with power plants. Finally, with NCAP_AFC(ACTGRP) you can define the availability for the stored energy even when also using NCAP_AFC(output), i.e. in a way you can then define both the output capacity and the storage capacity for the same process (this requires TIMES v3.8.3 or above).

Do i need to create an independent storage process?

If you want to define the storage capacity on both the seasonal and daynite levels, I would say that you need to create a separate process for the seasonal storage.