The project is called EnergySense and Google has begun collecting volunteers to test the energy-saving products it's building, according to Lessin.
This isn't Google's first attempt at an energy-saving and reporting product. A few years ago it worked on PowerMeter, which was a web dashboard that show energy consumption in homes.
Nest found early success making "unloved" home appliances smart. Led by former Apple executive Tony Fadell, the hardware startup makes smoke alarms and thermostats which learn your habits and adjust themselves accordingly. Nearly one year ago Nest raised $80 million from investors at an $800 million valuation. Then, it was shipping about 50,000 Nests per month at $249 per unit.