This paper presents the applications of meta-heuristics to power systems in Japan. In recent years, metaheuristics is noteworthy for a new optimization methodology. Meta-heuristics is defined as an optimization technique that makes use of heuristics or rules to obtain a better solution [l] . Meta-heuristics takes advantage over the conventional mathematical programming in terms of the flexibility of the cost function and constraints, the efficient algorithm capable of handling nonlinear mixed integer programming problems, and the evaluation of globally optimal solutions or approximate ones, As the typical algorithm, SA[2,3], GA[4] and TS[5,6] are well-known in the engineering fields. SA is based on analogy of heat bath for annealing of metal or crystal. It introduces a parameter called temperature into the algorithm so that the search area is controlled by the cooling schedule at each iteration. The state freely moves to other states at high temperature while it has limitations to move to others at low temperature. In other words, the solution converges to a value as temperature cools down. It makes use of the stochastic optimization to escape from local minima. Next, GA makes use of the idea of natural selection in the evolution process of biology. The variable is regarded as genes that consist of many attributes. Creating new genes gives better solutions in optimization problems. In practice, genetic operations such as crossover and mutation, etc. are introduced to improve the quality of the solutions. GA is also one of the stochastic optimization methods in a sense that the random number is used in the genetic operations. SA and GA are effective for solving small-size problems, but they do not work so well for large-scale problems due to the stochastic algorithm. On the other hand, TS is one of deterministic optimization methods. TS is an extension of the hill-climbing method that evaluates solutions by repeating local search around a solution. The difference between the hill-climbing method and TS is that TS has adaptive memory called the tabu list that fixes some attributes not to get stuck in local minima. It aims at evaluating better solutions near a global minimum with the iterative process of simple rules or heuristics. The recent simulation results have shown that TS is better than SA and GA in terms of computational effort and solution accuracy[7-141. 0-7803-7525-4/02/$17.00 0 2002 IEEE.