NIST 800-53 REV 5 • PHYSICAL AND ENVIRONMENTAL PROTECTION
PE-11(2) — Alternate Power Supply — Self-contained
Provide an alternate power supply for the system that is activated {{ insert: param, pe-11.02_odp.01 }} and that is: Self-contained; Not reliant on external power generation; and Capable of maintaining {{ insert: param, pe-11.02_odp.02 }} in the event of an extended loss of the primary power source.
CMMC Practice Mapping
No direct CMMC mapping
NIST 800-171 Mapping
No direct NIST 800-171 mapping
Related Controls
No related controls listed
Supplemental Guidance
The provision of a long-term, self-contained power supply can be satisfied by using one or more generators with sufficient capacity to meet the needs of the organization.
Practitioner Notes
This enhancement calls for a self-contained alternate power supply that does not rely on external power generation or fuel delivery. This is for environments that must remain operational regardless of external infrastructure availability.
Example 1: Install a combined solar panel and battery storage system sized to power critical systems independently. This removes dependence on fuel deliveries during extended outages. Design the system to power essential IT equipment for at least 48 hours of autonomy.
Example 2: For high-security installations, consider a natural gas generator with a direct pipeline connection (no fuel storage or delivery needed) combined with a large battery bank for instant switchover. Document the capacity and autonomy time in your continuity of operations plan.