Nvidia-smi -q -d power shows "Not Found" - why?

Developer Tools Other Tools System Management and Monitoring (NVML)
1

What causes “nvidia-smi -q -d power” to show “Not Found”?

Power Samples
    Duration                          : Not Found
    Number of Samples        : Not Found
    Max                               : Not Found
    Min                               : Not Found
    Avg                               : Not Found