Your concern is genuine, but you will need to a bit of homework. First, contact PS Audio and get the P600 idle power useage in watts. Second, add up all the idle power usages of the components plugged into it. Divide the grand total, in watts, by 1000 to convert to kilowatts. Multiply this number by 24 and then again by 30 to convert to kilowatt-hours you will use per month. For example, a system which idles at 100 watts will use about 72 kilowatt-hours per month. Third, on your electric bill find your power rate per kilowatt-hour. Fourth, multiply this rate by your by your total kilowatt-hours per month to get your estimated cost per month to let your system idle. Where I live, we have frequent power disruptions so I keep everything but my power filter, a TARA AD/10B, off.