Replace regular incandescent bulbs and fixtures with Energy Star–qualified compact fluorescent lights (CFLs), available at most hardware stores. CFLs cast a warmer glow than the cold, harsh fluoros of old. They cost more than regular bulbs, but they use 70 percent less energy, last much longer (10,000 hours, compared with 750), and look just as good.

Use task lighting. (You wouldn’t refrigerate the whole house to keep your food cold, would you?) One exception: If you have a torchère-style halogen lamp anywhere, get rid of it. It probably runs a 300-watt bulb and heats up to about 970 degrees.

Install dimmers on all bulbs to save energy and extend their life. Timers work well for front-door and security-related lights; sensors, which turn on lights only when needed, are ideal for outdoors. Solar-powered outdoor lights (www.solarilluminations.com has a wide selection) are an energy-free option.

Don’t underestimate the power of daylight. Use skylights and well-placed mirrors to reflect natural light and help reduce lighting costs.

Potential Savings: At least $90 a year.

Green Point: If every American home swapped just five incandescent bulb fixtures for Energy Star CFLs, it would keep 1 trillion pounds of greenhouse gases out of the air and save $6.5 billion in energy costs.