In keeping with the search giant's commitment to sustainability, Google is offering a free Halloween-themed calculator to help cut energy use. The calculator asks what you're haunted by: ghosts (eerie moans from open flue dampers), vampires (game consoles that use electricity when not in use) and other energy-wasting monsters in your home. It also offers up solutions, and calculates how much you can save on your energy bill by fighting these bogeymen.

The solutions Google offers aren't out of the ordinary: Programmable thermostats and CFLs both make the list. But the calculator does point to an advanced tips list that walks readers through a fairly extensive list of ideas on saving energy and cutting energy bills.

Google also goes into depth, explaining how particular actions can save you money — and how the calculator comes to a particular number.

On flue dampers, for instance, Google's site offers this: "The California Energy Commission, through its Energy Quest website, estimates that leaving the fireplace flue damper open can waste 8 percent of the average heating bill - which averages $1000/year. Daliceux and Nicolas found that leaving the flue open can waste 30 percent of the heating and cooling energy from a well-insulated house. We took the median of these 2 data points and estimate that leaving the fireplace flue open increases heating and cooling costs by 19 percent or $190/year."

Image — Google