HAWTHORNE, Calif.— Tesla Motors Inc. Chief Executive Elon Musk unveiled a line of home and industrial battery packs late Thursday, representing a strategic shift as his money-losing electric car company tries to break into a crowded energy storage market.

More than just a splashy evening party in a hangar at Tesla’s Southern California design studios, the event was the 43-year-old billionaire’s attempt to bring attention to an alternative business unit that has long been under development.

Mr. Musk says “power wall” batteries—ranging from a $3,000 7 kilowatt-hour wall-mounted unit to a $3,500 10 kwh unit—cost far less than the going rate for large-scale batteries and can be easier to install. Palo Alto, Calif.-based Tesla aims to begin delivering units by the summer from its California car factory, and later shift production to a $5 billion battery plant under construction near Reno, Nev.

Tesla also will sell massive battery blocks for industrial users and open-source the patents for the entire range, much like the company does with electric-car technology. Mr. Musk portrayed the effort as a breakthrough toward transforming energy use in favor of renewable resources.

“We’re talking about trying to change the fundamental energy infrastructure of the world,” he said during a public unveiling. “This is actually within the power of humanity to do. It is not impossible.”