CSP Tower with storage spiking issue

I'm having a huge issue with my power tower model. I'm using the newest version of sam and I am attempting to have it running in 9 operating times to cover the full load I have set for it. The problem is that if the TES fills up I end up with peaks in the power and it seems that the field does not de-focus in time so the output of the plant peaks massively (to the maximum extent of the power block).

At other times, especially when there is not enough energy coming in, the plant has spikes that occur, forcing the TES to drop its' charge rate to zero. This puts the next day in a bad situation (no thermal energy left to run the system) and leaves us with a massive energy spike the grid cannot handle.

I tried increasing the TES duration (hours of full load storage) but all that served was to create a massive spike every 3 months where the almost full TES would instantly lose all its' thermal energy.

If you have any ideas on what may be happening please let me know. I need this model to work for my master's thesis.

Hello,

You can control how SAM dispatches energy to and from the TES using dispatch optimization. On the System Control page, check the Enable dispatch optimization box, and then on the Time of Delivery Factors page, assign power price multipliers to the periods to represent the value of the system's electrical output at different times of day and year. For example, to limit discharge of TES thermal power during the day, you can assign a low multiplier such as 0.5 to the daytime TOD periods, and a high multiplier such as 1.5 to the evening and nighttime TOD periods. That would make it economically advantageous to keep the energy in storage during the day and dispatch it at night.

Note that the change the PPA price multipliers on the Time of Delivery Factors page, you should clear the Use library values box. To edit the periods in the Weekday and Weekend schedules, use your mouse to draw a rectangle in the schedule, and then type a number to set the period number.

Best regards,
Paul.

Hi Paul,

Thanks for the reply. Right now I don't have Dispatch optimization checked and instead I'm using the Grid on the System control page to set my control scheme. This works perfectly when there's a large amount of storage, but if I lessen the storage and the heat peaks then it instantly forces the system to output the maximum energy that the power block allows. I'll try changing the TOD to be the same as the system control but I figured that dispatch optimization would somehow ignore my system control scheme would it not?