A bitcoin startup plans to join Japan's growing ranks of power utilities and accept the cryptocurrency as payment for electricity charges, promising bills four to six percent cheaper than the competition.

ResuPress Inc., a Tokyo-based startup that runs a bitcoin exchange and storage service known as Coincheck, said it will also accept payment in yen and offer small bitcoin rebates to encourage use of the volatile currency.

"The use of bitcoin has been growing rapidly worldwide, but there are few places in Japan where you can spend it yet," said ResuPress chief Koichiro Wada.