Where to start:

• Steps to take that cost nothing, listed in order of energy (and money) saved, are: Lower your water heater temperature to 120^°F, lower your thermostat in winter, wash your clothes in cold water, turn off unneeded lights and electronics, and air dry your clothes in summer.
• Low-cost steps, also listed in order of savings: Install a programmable thermostat, seal large air leaks in your home, insulate your water heater, add insulation in your attic, seal and insulate your HVAC ducts, and install efficient showerheads.
• Additional steps: Conduct a home-energy audit, have your heating system serviced, and open curtains on south-facing windows during the day to allow sunlight to naturally heat your home and close them at night to reduce chill.

More about: Saving energy at home

The average American household spends about $1,900 annually on energy and also creates more than 26,000 pounds of carbon dioxide per year. Collectively, residential energy use accounts for about 20 percent of the country’s greenhouse gas emissions.

A flood of new products, and time-tested techniques, are available to help homes become more energy efficient. Here are tips, reviews, and the latest news.