If its possible check bellow line
Get-VM | Where-Object {$_.PowerState -eq "PoweredOff"} | Export-Csv -Path c:\poweredoff-vms.csv -NoTypeInformation
And if you want just few items you can filter them by using "Select"
Get-VM | Where-Object {$_.PowerState -eq "PoweredOff"} | Select Name,PowerState,NumCPU,MemoryMB | Export-Csv -Path c:\poweredoff-vms.csv -NoTypeInformation
For exporting csv file you can use "Export-Csv"