CET 25.1 Communication of changes

Update the user guide and announcement
https://cedars-2.cpuc.ca.gov/cet_ui/cet-user-guide/#avoided-costs

https://cedars-2.cpuc.ca.gov/cet_ui/cet-user-guide/#new-guidance-and-changes

Update the banner:
“CET version 25.1, for use in program years 2026–2027, is now in production, with Societal Cost Test (SCT) base and high case results available in outputs.”

Changelog posted