Open adam-a-a opened 1 month ago
This specific issue came from costing Softening > UF > RO
treatment train for the SETO project. UF CAPEX came out to ~$10.5M while the RO+Pump came to ~$2.5M. Naturally, this raised some eyebrows.
This is an exemplar of the mismatch we have in CAPEX/OPEX "scope" (I don't know the proper term) for some unit models.
In the case of UF, the reference (Texas Water Board, 2016; Table 3.20 & 3.21) has two costing relationships for UF:
CAPEX = $0.5M * (flow_mgd)
. I would argue this is more aligned with how we cost RO (i.e., only considering membrane-related costs and assuming a cost factor to account for the rest of the capital costs)The fix here is to use the value from Table 3.21 for UF ZO as the default parameter and apply a TIC factor to be aligned with the RO costing approach.
However, there are likely other instances of such misaligned scope for our costing approaches that need to be considered. I imagine this is not something that will be addressed in the near future, but should be a primary issue moving forward when thinking about modifications to WaterTAP's costing framework/scope/etc.
Tagging @TimBartholomew for visibility.
Costs assumed for ultrafiltration account for "total project costs" used in the source rather than direct equipment costs. We should revise to reflect the [reduced] cost relationship attributed to direct equipment costs.
Thus, we need to edit the
ultra_filtration.yaml
to reflect the desired costing. Tagging @kurbansitterley @zacharybinger @MuktaHardikar who were involved in this discussion.