7. Risk Assessment Concepts · Page 4 of 5
Economic Justification of SPDs
Compare SPD cost to downtime and hardware replacement.

Cost stack
Include hardware, engineering, install labor, and periodic cartridge replacement.
Loss stack
Include equipment replacement, callout labor, scrap product, contractual penalties, and reputation.
Typical result
For industrial and solar sites in storm-prone regions, staged SPDs usually pay for themselves after one avoided event.
