TOKYO — Masayuki Hattori, 46, lives with his extended family of seven in a house in the middle-class Itabashi neighborhood of Tokyo. Five years ago, he received a sales pitch from Tokyo Electric Power Co., which had teamed up with appliance makers, that he found too attractive to ignore: Switch from gas as the fuel of choice for his home’s heating and cooking and go “all electric.”

The package deal offered solar panels for home generation of electricity, grid connection for Tokyo Electric to provide backup power — and buy any surplus power generated by the panels — and a full range of electrical home appliances. It would provide all the energy that Mr. Hattori and his family would need and would also help the environment. It seemed like a win-win proposition.

“We were also concerned about the safety for our aging parents, who were growing forgetful,” Mr. Hattori said. “They might turn on the gas cooker, forget about it and go out into the garden, for example.” A no-gas home would give him peace of mind, he said, so in 2006 he paid ¥3.5 million, or $46,000, for the package.

For Tokyo Electric, known as Tepco, Mr. Hattori’s home was one of hundreds of thousands it was converting annually into electricity-only homes in the greater Tokyo area.