Well, you’re both right. The Pi’s power consumption is quite low. But not the power consumption of my nas.
The problem is: My NAS powers down every night at 01:15 and powers up at 12:00 again. That means I’m saving round about 11 hours x 50 (or 70?) watts a day (*365 days). That means I am saving a little more than 200 kWh or about 60,- € per year. I won’t get poor, but I would waste it without benefit…
But there is running a script on my nas which prevents it from shutting down, if there is a client connected to the nas. When I am using my Windows-PC or streaming media, the nas will wait with shutting down, until the connection to the client is disconnected, for example if I am watching movies from the nas until 04.00 in the morning.
That means the nas would run around the clock, because the Pi ist connected to it. That is the reason why I have to switch the Pi off.
I hope this was understandable. Sorry for my English.