Japan's 10 former regional power monopolies have had a difficult few years with nuclear issues and commodity price volatility. The latest challenge came after the country's retail power market was fully liberalised in April 2016. Competition is hitting Japan's power utilities as their customers switch to new suppliers. But it's not just retail competition the power utilities need to worry about. New coal, gas and solar additions along with potential nuclear restarts mean a sharp increase in generation capacity. So Japan's power utilities face growing retail and wholesale competition in an electricity market that has recently shrunk.