The surge protector doesn't use energy. The current that carries Energy may pass through it but a good surge protector won't consume any of that energy. It'll just pass through the surge protector. The current that carrys the energy passes through it to be used by devices further on down the line, such as a toaster or a welder. If those devices are using 1.8 kilowatts of power, then that means that 6,480,000 Joules of energy pass through the surge protector in one hour. They all come out the other end and keep going.