TOKYO -- Electricity demand has surged in Japan since a cold wave hit many parts of the country starting last month. But the situation also reveals flaws in the power system and highlights challenges that lie ahead for decarbonization.
Since last week, power companies across Japan have been experiencing days when their capacity factor -- the ratio of actual to maximum output -- exceeds 95% of their generation capacity. Normally, a reserve ratio of 7-8% is required for a stable supply. When the reserve ratio falls below 3%, it becomes difficult for operators to cope with sudden volatility in demand.