The aim of this paper is to present the way of thinking how to secure sustainable electric energy in Tokyo metropolitan area, the capital of Japan, after the Great East Japan Earthquake and the accidents of Fukushima Daiichi nuclear Power Plant from our comparative study of Singapore by GCP project. As Tokyo has faced with big challenge to introduce the whole renewable energy systems, it is very effective to maintain good situations in not only environment but also in economic competitiveness and supply electric power sustainably in the capital sphere by developing smart grid, electricity market mechanism, and demand response scheme. In result, the crucial point is to control electric energy strategically and comprehensively from technological and social standpoints
