日本在福岛事故后已有五家主要电力公司重启核电机组，核电与水力等非化石电源有助压低电价。九州电力与关西电力今月家庭平均电费约为7,466日圆与7,791日圆，明显低于尚未重启核电的东京电力8,634日圆与北海道电力9,376日圆。依赖煤炭与天然气等化石燃料比例越高的地区，电价越高且易受国际价格波动影响。

九州地区所有核电机组皆在运转，加上长日照带动太阳能扩张，2024年度无碳电源已占其发电结构的56%。稳定且相对低廉的电价吸引了先进制造与数据基础设施，包括台积电在当地兴建晶圆厂，以及多座新建资料中心。原先被预期会下滑的九州用电量，如今被跨区电力运营机构预估到2034年度十年间将累计成长约4%。

目前北海道电价是日本最高，北海道电力供电区域广大，又高度依赖曾在2018年地震停摆的苫东厚真燃煤电厂，暴露供电风险。若泊核电站3号机重启，公司预计家庭电价可下调约11%、企业用户平均降价7%，核电每度电较化石燃料便宜约7至8日圆，年度损益改善约500亿日圆。未来若1至3号机全数重启，2030年度电源结构将朝化石燃料与核电各约4成、再生能源逾2成发展，有利吸引Rapidus、软银等半导体与资料中心进一步投资北海道。

Five of Japan's major utilities have restarted nuclear reactors, and regions with lower fossil fuel dependence now offer cheaper power. Kyushu Electric and Kansai Electric charge about 7,466 yen and 7,791 yen per month, versus 8,634 yen at Tokyo Electric and 9,376 yen at Hokkaido Electric, which have not restarted any reactors. Areas that still rely heavily on coal and natural gas face higher and more volatile costs, linking nuclear restarts directly to reduced household electricity rates.

In Kyushu, all reactors are online and solar generation is growing, so carbon free sources reached 56% of the region's power mix in fiscal 2024. The expectation of inexpensive, stable electricity has attracted advanced manufacturing and digital infrastructure, including Taiwan Semiconductor Manufacturing's fabrication plants and a wave of new data centers. Electricity demand in Kyushu, once projected to decline, is now forecast to grow about 4% over the decade through fiscal 2034.

Hokkaido currently has Japan's highest electricity rates, partly because Hokkaido Electric serves a wide area and depends on the Tomato Atsuma coal plant, which has been vulnerable to earthquakes. Restarting Tomari Unit 3 is expected to cut household tariffs by about 11% and corporate rates by 7%, while nuclear generation enjoys a 7 to 8 yen per kilowatt hour cost edge and improves profits by roughly 50 billion yen annually. With plans to restart three units and move toward a 40% fossil, 40% nuclear and over 20% renewable mix by fiscal 2030, Hokkaido aims to stabilize supply and lure chipmakers, data centers and other power intensive industries.