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NREL / SAM

System Advisor Model (SAM)
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2024 Release Defaults Updates #1855

Open brtietz opened 2 months ago

brtietz commented 2 months ago

Consolidate defaults updates into one issue since they are typically one PR:

  1. Originally https://github.com/NREL/SAM/issues/1794

      > There's a minor consistency issue in the defaults: the default PBI term for front of meter is 10 years, whereas for BTM it's 0 years. That should be a separate issue if we choose to address it and can probably wait until the release.

I think the default term should be zero if the default amount is zero to force the user to set both the PBI amount and term -- otherwise they may just set the PBI amount and not notice the term.

  1. Originally https://github.com/NREL/SAM/issues/1816

Default modules in SAM are far smaller than what is being deployed right now. Behind the meter panels are closer to 400 W, while utility scale modules are 550 or more. See https://www.nrel.gov/docs/fy23osti/87303.pdf for details (there may be a newer report near release time.

  1. Originally https://github.com/NREL/SAM/issues/1829

Hybrids depreciation defaults as of the release candidate for 2023-12-17-r2:

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As compared to PVWatts-Single Owner:

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Consider updating to match. (PV-Battery-Fuel cell matches the other hybrids)

Additional consideration: anything with "generic system" probably shouldn't have assets qualify. Consider if this case should have different default allocations.

The default allocations are based on a utility-scale PV system (based on work done in 2011). I'm not sure if they would be appropriate for a hybrid system or other types of systems. Assuming 100% 5-yr MACRS allocation is a simplification, but may be appropriate when more information is not available.

My other concern is that the ITC qualification box is unchecked in a case where there are eligible assets. Perhaps the fix is just to check the ITC box?

mjprilliman commented 1 month ago

-Revisit default modules and module efficiencies

mjprilliman commented 4 weeks ago

Default Custom Generation Capex is $1billion. Might be worth revisiting (also true for hybrid configs).

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brtietz commented 3 weeks ago

Update the battery replacement default to 70%. This aligns with industry warranties (such as Tesla Powerwall)

Plan to make the BTM and utility scale defaults the same for now, but we can update this in the future with better data.