We have some sites that have a "real" server (Dell PowerEdge etc) with dual power supply, RAID… that were bought some years ago, and suck 100-125 watts! Plus "ordinary" desktop-size servers that draw around 55 watts. These use way too much power to leave on through 6-9 hour gaps in mains power. Yes, I will be glad to be not dependent on them ASAP.
We are in the process of moving to the Fit-PC3, 9 or 10W. So, along with Alix board pfSense 6W, and a TP-Link (4-port Gb ethernet switch+WiFi AP) 6W, and a front-end ISP device (ADSL modem, WiMax device...) 6-8W, we will be able to keep a core network running for 30W total. With a couple of 80W solar panels and suitable battery/s it can be off the mains completely. This will allow the Windows domain controllers to stay up 24/7 and talk to each other across OpenVPN all night - finally we will be able to sync big files to/from head office at night and so on.
Until that is installed everywhere, I will try the workaround DNS stuff - it sounds like @joako has done it with success.