And that’s the problem right there. That’s 12w idle power. The computer is not going to idle all the time and power consumption will rise. If you are like me and live in a place with high cost of power this will add up. The raspberry pi will is at max 9w of power. That’s max. At idle it’s more likely to be around 3 but could be more if you have some usb drives plugged into it.
Maybe consider selling your pi2g and buying a pi4g or 8g.