We propose a wireless power distribution system (WPDS) operating at 2.45 GHz CW in buildings instead of wired power distribution in order to reduce the initial cost of the building. Required technologies for the WPDS are (a) low-cost and low-loss deck plate waveguide, (b) variable microwave power distributor for the waveguide, and (c) high-power (>100 W) rectifier at the outlet. We developed and tested the deck plate waveguide, power distributor, and high-power rectenna consisting of 256 Si Schottky barrier diodes and newly developed GaN diodes. Finally, a test WPDS was built and microwave power transmission experiments were conducted. The total efficiency of the test WPDS was estimated to be 52%.