solid-powermanagement: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/solid-powermanagement - from package: kdebase-workspace

You may install the required package with command yum install {package}

Error in other languages:
solid-powermanagement: bevel nie gevind nie
solid-powermanagement: comandă negăsită
solid-powermanagement: comando não encontrado
solid-powermanagement: commande introuvable
solid-powermanagement: command not found
solid-powermanagement: käsku ei ole
solid-powermanagement: không tìm thấy lệnh
solid-powermanagement: komanda nerasta
solid-powermanagement: Kommando nicht gefunden.
solid-powermanagement: kommandot finns inte
solid-powermanagement: komut yok
solid-powermanagement: nie znaleziono polecenia
solid-powermanagement: níor aimsíodh an t-ordú
solid-powermanagement: no se encontró la orden
solid-powermanagement: no s'ha trobat l'ordre
solid-powermanagement: opdracht niet gevonden
solid-powermanagement: parancs nem található
solid-powermanagement: perintah tidak ditemukan
solid-powermanagement: príkaz nenájdený
solid-powermanagement: příkaz nenalezen
solid-powermanagement: команда не найдена
solid-powermanagement: командата не е открита
solid-powermanagement: 命令找不到
solid-powermanagement: コマンドが見つかりません