Through reusing its waste, Kawasaki King Skyfront Tokyu REI Hotel supplies 300,000 cubic nanometres of hydrogen per year, generating 450,000 kwh of power. This amount of energy would produce enough electricity for 82 households of four people per day per year.

Kawasaki King Skyfront Tokyo Rei Hotel recycles toothbrushes and hair combs left in its guestrooms, which become past of the plastic waste converted into hydrogen that powers the hotel.

In addition, the hotel grows its own produce inside the hotel through hydroponics (the process of growing plants without soil) and LED light source photosynthesis. For example, the hotel can grows pesticide-free lettuce inside its lobby, which it harvests once per month.