Keep EMP-aware spares and offline settings backups
A failed charge controller or inverter can stop the whole system for weeks if parts must be shipped. A small, protected spares kit and saved settings let you repair it yourself or with a local electrician.
How
- Keep a spare charge controller and a second, smaller inverter that can run the critical loads alone.
- Add a spare main fuse and holder, one fuse of each branch rating, SPD cartridges, PV connectors with the matching crimp tool, a battery temperature sensor, the BMS communication cable and cooling fans.
- Print every device's settings and keep a firmware and configuration backup on a USB stick with the spares, so a replacement unit can be set up offline.
- Store spares unplugged. CISA's EMP guidelines advise unplugging power, data and antenna lines from spare equipment, and wrapping spares in foil or putting them in Faraday containers.
- ORNL describes PV systems as particularly susceptible to EMP because they sit outdoors, and its tests show solar inverters are vulnerable.
- Bury long DC cable runs where practical and fit surge protection (power-19). How well a home metal box protects against EMP is unproven, so treat spares as the main defence.
- Log each spare in the critical spares register (continuity-16) and check it yearly.
Safety: Swap controllers and inverters only with the battery and PV isolated. Replacement work on fixed wiring needs a competent electrician.
Do these first
Sources
- Electromagnetic Pulse (EMP) Protection and Resilience Guidelines for Critical Infrastructure and Equipment, v2.2 (2019). US Cybersecurity and Infrastructure Security Agency (CISA), accessed 2026-11
- Modeling, testing, and mitigation of electromagnetic pulse on PV systems (Solar Energy, 2023). Oak Ridge National Laboratory, accessed 2026-11
- Balance-of-System Equipment Required for Renewable Energy Systems. US Department of Energy, Energy Saver, accessed 2026-11