Ed Lu, the public face of energy at Google, has turned in his lava lamp.

The former astronaut, who served as the program manager in the advanced products group at the search engine, plans on writing a book on his experiences as an astronaut and space shuttle pilot, he told us during a break at the 2010 Silicon Valley Energy Summit sponsored by the Silicon Valley Leadership Group taking place at Stanford. Lu served at NASA for 12 years and flew two shuttle missions after the Columbia disaster. He also flew a Soyuz mission in conjunction with Russia and spent six months on the International Space Station.

Following that, he worked on a program to develop spacecraft that could deflect rogue asteroids from striking the Earth and causing massive damage.

Yes, it was probably more interesting than devising a in-home display for energy consumption. During his time at Google, Lu continued to work with space agencies on the asteroid project.

He left Google about a week ago.

At Google, Lu's job often revolved around speaking at conferences and discussing PowerMeter, the company's software for tracking power consumption in homes. Ultimately, PowerMeter may be used to control appliances and other devices in the home. Google has also obtained a license to sell power like a utility. Some believe that Google ultimately will act like a utility and compete with companies like PG&E.

One of the more difficult tasks Lu had was telling the world that PowerMeter was devised strictly as a charitable product.

"We are not trying to build a business model around it," he said at VentureBeat's GreenBeat conference last year. PowerMeter was part of Google.org, he noted, the company's philanthropic arm.

The official stance from Google drew some guffaws. And still does. Last night I attended a panel on smart grid when Google's charitable take on PowerMeter came up. A utility exec laughed out loud.