Obayashi Corp. is considering building a wind power project with as much as 455 megawatts of capacity off the coast of Akita Prefecture, amid a push by the local government to expand the use of clean energy.

The Tokyo-based construction company plans to begin an environmental impact assessment as early as this month after the prefecture said it will help with its surveys of the area, Junichi Ichikawa, a spokesman for Obayashi, said Tuesday.

The environmental study will help decide the ultimate size of the project, he said. Construction may begin in 2020 and the plant could be operational by 2024, according to an emailed statement from the prefecture. Partners in the project will be considered later, it said.

Obayashi already plans to build two other offshore wind projects in the prefecture with Marubeni Corp. and Eco Power Co. The plants will be located near the ports of Akita and Noshiro, according to Obayashi's website.