Sam 1855 defaults updates

[brtietz]

Pull Request Template

Description

2024 Defaults updates including:

• Battery replacement percent is now 70% (increased from 50% to trigger replacement with default degradation)
• Wind, and battery costs from the 2024 ATB (see details in SAM documentation to account for recent trends in costs)
• PV costs from the 2024 SETO benchmark: https://www.energy.gov/eere/solar/solar-photovoltaic-system-cost-benchmarks
• Change custom generation capital to $1/W
• Updated PV system sizes and modules to match the benchmark
• Align depreciation assumptions with ITC assumptions for hybrids
• Set default PBI term to zero
• Inflate PTC to 2024 value ($0.03/kWh)
• Update PPA prices given all of the above

Fixes ##1855

Type of change

Please delete options that are not relevant.

• New feature (non-breaking change which adds functionality)
• This change requires updating the PySAM files via export_config. Please see When do the PySAM files need to be regenerated?

Checklist:

If you have added a new compute module in a SSC pull request related to this one, be sure to check the Process Requirements.

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules
• I have checked my code and corrected any misspellings

[sjanzou]

Looks good and a great deal of detail for all of the module and inverter models!

Is everyone okay with the DC Optimizers and the string inverter for the residential case?

[sjanzou]

Is this a tolerance issue (0.04 changed to 0.400001)?

[brtietz]

Probably during some of the calculated value updates. Where would you recommend enforcing the tolerance?

[sjanzou]

Probably during some of the calculated value updates. Where would you recommend enforcing the tolerance?

Maybe we can setup the CI to run the calculated value update twice and hopefully they will not change after that...Looks like it is a formatting as float issue with 6 digits of precision in the calculated values.

[sjanzou]

Why is om_batt_replacement_cost so much cheaper for BTM (184) versus FOM (252)?

[brtietz]

Good point, I was copying the per kWh value from the installed costs page:

Utility scale:

Commercial scale:

These are based on "best fits" for total costs at different scales. Given that commercial scale batteries usually have shorter duration for peak shaving, this might just be an artifact of that input data.

[janinefreeman]

Are we confident in this? Noting that residential goes back up to 434?

[brtietz]

New value is 280 per kWh. I took the per kWh and per kW values in the ATB, normalized per kWh, then multipled by 0.8 to account for components that can be re-used to match the replacement assumptions in the ATB PV+Battery code. (dollar/kW + dollar/kWh * 4)/4 * 0.8.

[sjanzou]

Glad you are updating all the "hidden" models!

[sjanzou]

Wow, a 4x increase in recapitalization for Geothermal - is this from the GEOVision study?

[brtietz]

@mjprilliman Any insights on why this would change? This was updated automatically by https://github.com/NREL/SAM/blob/develop/deploy/overwrite_all_defaults.lk

[mjprilliman]

There must have been geothermal default changes after the script was run in the last release, as the calculated value in 2023.12.17 shows 69M rather than 28M due to a large change in pump costs to better align with GETEM. This year, the change to 87M is due to the default drilling cost curve changing from intermediate to base. The cost is calculated in the UI from confirmation drilling costs + drilling costs + pumping and surface equipment costs.

[brtietz]

Is everyone okay with the DC Optimizers and the string inverter for the residential case?

We went with the Solar App+ reference for this: https://www.nrel.gov/docs/fy24osti/89618.pdf The LBNL tracking the sun report also showed a pretty even split between these two.

The default Detailed PV / Residential case results in 3.5% MPPT clipping, which may not be realistic for a system with DC optimizers, but reflects a possible limitation in SAM's current ability to model optimizers. Because this is a common design, I think it's ok to use this as the default. It will keep us reminded of our wishlist item: #209

[mjprilliman]

Do you have a reference point for the detailed PV commercial default being bifacial fixed tilt 20 degrees? I understand it's just using the same module as utility-scale. Also, if detailed PV default module is bifacial, shouldn't PVWatts be bifacial as well?

Everything else looks good from spot checking.

[cpaulgilman]

Noting for future reference:

• The default Sungrow SG250HX inverter for the Detailed PV / Commercial case has 12 MPPT inputs. SAM models the inverter with a single MPPT input, so all strings operate at the same voltage.
• The PV-Battery default cases uses the same PV system design as the Detailed PV defaults with an AC-connected battery, so the default PV inverter does not convert battery power.
• Based on quick web research, the default Sungrow SC2500U for FOM defaults may be a bit out of date (circa 2018). Consider switching to SG series for a more current model.

[janinefreeman]

Are we confident in this? Noting that residential goes back up to 434?

[janinefreeman]

Did we intentionally choose a different temperature here? Other files have a default of 25 C. I don't know if this is a question for @brtietz or @mjprilliman .

[mjprilliman]

Probably just got overlooked, I will update

[janinefreeman]

Interesting that this value increases for commercial when other values decrease?

[brtietz]

Custom generation profile O&M is a potentially bit arbitrary - see email from Paul on 11/15.

[janinefreeman]

Difference in precision between this and standalone battery residential (15)? Custom battery residential appears to have 14.81 as well

[janinefreeman]

Similar question, checking that this is 12 when custom battery commercial and pv battery commercial are both 5.25

[brtietz]

Custom and PV both have some "standard" O&M captured in the main plant capacity numbers (e.g. rolling a truck to the site for inspections, monitoring software). Stand alone battery has a higher battery capacity number to capture these costs.

[janinefreeman]

Maybe I missed something, but I think community solar costs might need some attention. They don't seem consistent with either commercial or utility, but also are not reliably in between (by individual cost category)

[brtietz]

Fixed in latest push