Compact Fluorescent Lights (CFLs)
Most lighting was replaced with compact fluorescent light bulbs (CFLs). These bulbs use approximately one quarter of the energy that standard incandescent bulbs use, and they last longer. In addition, they generate less waste heat, which reduces cooling loads for the home in summer. The price of CFLs has dropped to about $10 for a package of six. Simple and inexpensive, changing light bulbs is one of the most cost-effective ways to start moving toward net zero energy.