Several resources can help the engineer craft a lifecycle cost analysis (LCCA).
"Fundamentals of Life Cycle Costing for Energy Conservation" is a 5.5-hour continuing education course developed by the Dept. of Energy and NIST in 2014. The course is available as a free webcast on the Whole Building Design Guide website: https://www.wbdg.org/education/femp19.php
NISTIR 85-3273-29, "Energy Price Indices and Discount Factors for Lifecycle Cost Analysis – 2014 Annual Supplement to NIST Handbook 135," provides energy price indices and discount factors; the factors are calculated with the latest FEMP discount factors and energy price escalation rates for US Census regions, rate types, and fuel types. The document may be downloaded for free: https://dx.doi.org/10.6028/NIST.IR.85-3273-29
NIST Handbook 135 (HB 135), "Lifecycle Costing Manual for the Federal Energy Management Program,"explains in detail the principles of lifecycle cost analysis and integrates them with FEMP criteria; the handbook can be downloaded for free: https://www.nist.gov/customcf/get_pdf.cfm?pub_id=907459