Storage-Power tower- Mismatch between charged and discharged energy

Hello Paul

Is TES considered to be fully charged at the start-up of the plant? As you can find in the attached file, TES in the first 24 hours has been charged with 230 MWh energy, but it has delivered 398 MWh. What is the reason for this? Is it possible to consider TES fully discharged at the beginning of the year of operation?

Many thanks.

Saeed

Hi Paul,
In the first attached file, the initial hot HTF percent is fixed to 30%, I guess the reason for mismatch could be this issue. However, I tried to fix this parameter to 0% and the simulation failed to complete. Is this a simulation error or a SAM limitation?

Dear Saeed,

For the molten salt power tower model with storage, if you set the Initial Hot HTF Percent to zero, the simulation fails. I suspect that is because of a divide-by-zero error or similar calculation error in the model's algorithm. The simulation seems to work if you use a small number for that input (I tried 1% and 0.01%). I will check with the CSP developers to see if they have any other suggestions.

Best regards,
Paul.