6 Talk

Mr. Fusion

Marty: "Wait a minute, what are you doing Doc?"

Doc: "I need fuel!"

— Marty and Doc while refueling Mr. Fusion with garbage

The Mr. Fusion Home Energy Reactor was the name of a power source used by the DeLorean time machine. The actual unit was manufactured by Fusion Industries.

Also known as the fusion generator, the Mr. Fusion Home Energy Reactor converted household waste to power the time machine's flux capacitor and time circuits using nuclear fusion. (It is thought that this is cold fusion.)

We first see the Mr. Fusion when Emmett Brown comes back from 2015. He rummages through Marty's trashcan to find a banana peel, a Miller beer can (pouring in the remains of the beer, and then dropping the can in too), and some other pieces of garbage which he drops into the unit before closing it. Which, in turn, suggests that the Mr. Fusion unit can run on pure trash.

Mr. Fusion allowed the DeLorean time machine to generate the required 1.21 gigawatts to travel through the space-time continuum. The energy produced by Mr. Fusion replaced plutonium as the primary power source of the DeLorean's time travel and flight capabilities.

When Marty, Doc, and Jennifer arrive in the year 2015, a few logos are spotted for Fusion Industries on the power generators in the alley they land in. The generators resemble the shape of a very small truck.

Behind the scenesEdit

Mr. Fusion was based from a Krups coffee grinder and was a parody of the Mr. Coffee line of coffeemakers.

The ending of Back to the Future suggested that in the future, mankind's energy problems would be solved by a device that would convert any matter into energy, and that the "Mr. Fusion" (seen on the back of the DeLorean) could, in theory, someday be able to power automobiles. However, vehicles seen in Back to the Future Part II don't have a Mr. Fusion, and the Texaco service station in 2015 is still in operation (It is possible the Mr. Fusion comes from a later time period that Doc travelled to). In Back to the Future Part III, Doc confirms that the fusion device only powered the flux capacitor and the time circuits, and that the DeLorean time machine still had an internal combustion engine that ran on gasoline.

In the novelization, Doc has to take care in 2015 to keep the DeLorean obscured, citing that many of his modifications – specifically the installation of a Mr. Fusion Home Energy Reactor – are not exactly considered "street legal".

"Mr. Fusion powers the time circuits and the flux capacitor. The engine runs on ordinary gasoline. It always has."

—Doc to Marty