NIRASAKI CITY, Japan—Megumi Arakida has a blue and white electric washing machine in her home, but she doesn't use it. She is scrubbing her clothes on an old wooden washboard her husband got from his grandmother.

The 35-year-old has also given up her electric toothbrush, vacuum cleaner and—despite the reservations of her husband, Makoto—the couple's 24-inch television, all in a zealous quest to save electricity.

Now,...