Battery Single Owner SAM Model - 30-min timestep

Hi

I am trying to run a custom 30-min time series dispatch for a battery on SAM, under the battery single owner model. I change the timestep to 30 minutes from 60 minutes, but I get the following error. How can I make the simulation run on a 30-minute basis, instead of hourly?

exec fail(battery): Length of batt_custom_dispatch must be 8760 * steps_per_hour.
Simulation battery failed :exec fail(battery): Length of batt_custom_dispatch must be 8760 * steps_per_hour.
monthly_grid_to_batt not assigned
Simulation singleowner failed :monthly_grid_to_batt not assigned

Hi Giorgos,

It looks like the Standalone Battery model may not work with sub-hourly time series dispatch inputs: github.com/NREL/ssc/issues/994 . We plan to fix this issue for the Fall 2023 release of SAM.

Are you using the Standalone Battery model or one of the other battery configurations (Detailed PV-Battery or Generic System-Battery)?

Best regards,
Paul.

Hi Paul

Thank you for your answer. I am using the Standalone Battery Model. The other models that SAM has are not suitable for my case.

By the way, I would also like to ask you if it is possible to have a Standalone Battery (no financial) model, as I am using it in line with MATLAB and it would be great if I could get a much faster simulation. I noticed that when I export SAM standalone battery model in MATLAB equivalent code, there are too many financial parameters and economic operations, making the code too lengthy and slow. So, is it possible to have a similar battery model, but without a financial model? Or, is any other way to make SAM model to run faster on MATLAB?

Thank you
Giorgos

Hi Giorgios,

The Standalone Battery model requires a financial model for dispatch options that respond to power prices, electricity rates, and or electric load, which are all part of the financial model. It also requires a financial model to account for battery replacement costs.

If you are running the model from MATLAB, you could isolate financial model inputs required by the 'battery' compute module, and set those yourself in the code instead of relying on the inputs from the financial model. You can use SDKtool to explore the compute module inputs:  sam.nrel.gov/software-development-kit-sdk .

Best regards,
Paul.