Your energy bill consists for over 50% from heating costs. When your home thermostat isn't efficiëntly programmed, you're waisting lots of that energy. The Nest learning thermostat programs itself and shows how many ernergy you are using at any moment. So no more guessing how high your energy bill will be this month, but saving energy and money!
The thing you need to connect the thermostat is 230V
The Nest Thermostat from Google now also is usable in a Z-wave domotical environment because of the so called plugins that FIBARO uses in the Home Center 2 and in software version 4 in the Home Center Lite.