US DOE 10 CFR 436.14: Federal Solar Life Cycle Costing Guide
Updated 6 September 2026 · By SolarNevs Research Desk, Dealer surveys + verified sources · 1 source · Method ↗
Key Takeaways
- Title 10 CFR Part 436 Subpart A (§ 436.14) establishes mandatory methodological assumptions for federal solar Life Cycle Cost Analyses (LCCA).
- Caps evaluation study periods at 25 years from the beginning of beneficial use (or expected equipment life, whichever is shorter).
- Mandates annual FEMP discount rates published in NIST 85-3273 derived from a 12-month average of U.S. Treasury bond yields.
- Enforces energy price escalation projections developed by the DOE Energy Information Administration (EIA).
- Requires all constant dollar costs and savings to reference the designated base date.
Statutory Authority & Federal Energy Management Scope
Under Title 10 of the Code of Federal Regulations, Part 436, Subpart A governs federal agency capital planning under the National Energy Conservation Policy Act (NECPA).
Section 436.14 provides uniform economic criteria for comparing on-site solar energy generation against conventional utility electricity procurement.
Methodological Assumptions Under Section 436.14
Federal agencies must formulate solar economic justifications using strictly defined parameters:
Economic Parameter | Regulatory Standard & Statutory Limit | Statutory Reference |
|---|---|---|
Existing Building Retrofit Study Period | Expected life of retrofit or 25 years from beneficial use, whichever is shorter | 10 CFR § 436.14(a)(1) |
New Building Designed Systems | Expected life of system or 25 years from beneficial use, whichever is shorter | 10 CFR § 436.14(a)(2) |
Discount Rates | Annual supplement to Life Cycle Costing Manual (NIST 85-3273) | 10 CFR § 436.14(b) |
Nominal Discount Rate Formulation | 12-month average of composite yields of long-term U.S. Treasury bonds | 10 CFR § 436.14(b)(1) |
Real Discount Rate Formulation | Derived from nominal rate adjusted for general inflation | 10 CFR § 436.14(b)(2) |
Energy Price Escalation | Official forecasts projected by DOE Energy Information Administration (EIA) | 10 CFR § 436.14(c) |
Base Date Costing | All constant dollar costs and savings must reference base date | 10 CFR § 436.14(d) |
Capital Planning Compliance for Federal Solar
When submitting solar energy proposals for federal facility appropriations:
- Life Cycle Time Horizons: Financial models cannot extend beyond 25 years of commercial operation.
- Standardized Energy Rates: Planners cannot use unverified commercial utility inflation assumptions; EIA forecast tables are mandatory.
- Terminal Salvage Accounting: Any remaining economic value of inverters and solar PV racking at the end of the study period must be credited back to total life cycle costs.
Frequently asked questions
What is the maximum study period allowed for federal solar retrofits under 10 CFR 436.14?
Under 10 CFR § 436.14, the study period for evaluating solar retrofits in an existing federal building is the expected life of the retrofit or **25 years** from the beginning of beneficial use, whichever is shorter (August 2026).
How are discount rates determined for federal solar life cycle cost analyses?
Discount rates are published annually in the supplement to NIST 85-3273 for the Federal Energy Management Program (FEMP), based on a 12-month average of composite yields of outstanding U.S. Treasury bonds (August 2026).
What energy price escalation projections must federal solar LCCA use?
Agencies must assume energy prices change at rates projected by DOE's Energy Information Administration (EIA) and published annually by NIST (August 2026).
How are constant dollar values referenced in federal life cycle cost analyses?
All constant dollar costs and savings must be referenced to the base date (August 2026).
References
- LII / Legal Information Institute: 10 CFR § 436.14 — accessed 31 August 2026
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