This is just an interesting data point... Using a P3 Kill-A-Watt (http://www.p3international.com/produ.../P4400-CE.html) we measured the energy usage of our original PC based Asterisk system and its replacement Pika Warp system. For us, the PC based system cost an estimated $130 US dollars per year in enery usage. The Pika is estimated to cost around $20!