Wind power: Whirring blades atop a 50-foot pole generate a small, unmetered portion of the household's electricity needs. In hindsight, they wish they'd opted for a 70-foot tower: The power generated rises with greater wind speed, which is affected by height.
High-efficiency HVAC: Heating and cooling account for 46 percent of energy costs in a typical home, says the U. S. Department of Energy (DOE). The Manns upgraded their decades-old systems with a 95-percent-efficient furnace and central air with a rating of Seer 13 (equivalent to Energy Star).
Ceiling fans: In summer these air movers allow a 4-degree increase in temperature with no loss of comfort, says the DOE. The Manns added seven inside and reverse the blades' direction in winter to lessen the need for heat.