Tohoku Electric Power Engineering & Construction Co., Inc.

TOHATU, formally Tohoku Electric Power Engineering & Construction Co., Inc. (東北発電工業株式会社), is a Japanese comprehensive engineering company and a member of the Tohoku Electric Power Group. Headquartered in Sendai, Miyagi Prefecture, it was founded in 1959 and has spent more than six decades building, supporting and protecting the power-generation assets that keep electricity flowing across the Tohoku region and Niigata Prefecture. Its self-description is that of a professional engineering group that "makes" and "protects" power-source facilities with high technical capability, working alongside Tohoku Electric Power to support the energy needs of its home region. The company's business is organized around two broad customer groups. For power producers, it works on thermal, hydroelectric, nuclear and renewable-energy power stations. For owners of factories and industrial plants, it serves biomass-related facilities, clean centers, smelting plants, paper mills and cement plants. Its service menu spans electrical equipment work, emergency power-source installation, instrumentation, control and communication work, turbine and boiler equipment work, utility equipment work, boiler solutions, advanced welding, and the sale of concrete and civil-engineering materials. This mix places TOHATU squarely in the engineering, procurement and construction (EPC) and plant-maintenance space for the energy and heavy-industry sectors. TOHATU's footprint is concentrated in the six prefectures of Tohoku plus Niigata Prefecture, with additional presence in Tokyo. According to the company's own figures, it operates 32 business locations including a technical training center and a technical development laboratory, and employed 1,709 people as of March 31, 2026. In fiscal 2025 it recorded 3,914 projects — 264 construction and removal jobs and 3,588 maintenance jobs — and sales of 73.8 billion yen, with stated capital of 1 billion yen. These numbers underline that maintenance, inspection and plant-life-extension work, rather than only new-build construction, form the backbone of its business. Technically, TOHATU has built distinctive capabilities in welding and non-destructive inspection. Its Rifu manufacturing plant handles piping work subject to self-inspection under Article 52 of the Electricity Business Act, covering sales, design, execution, welding and inspection, and is used as an evaluation-test venue by the Japan Welding Engineering Society. The company has also developed a patented device (Patent No. 5085115) that integrates ultrasonic testing with three-dimensional coordinate measurement to map defect positions and surface shapes, with more than 20 applications mainly in Fukushima Prefecture, where results help customers decide when to refurbish hydro turbines. As a Tohoku Electric Power Group company, TOHATU aligns its sustainability work with the Tohoku Electric Power Group Sustainability Policy and pursues a management vision for 2030. Its stated mission is to support the lives of people in Tohoku and Niigata with electricity, and it presents itself as a place where employees can work with a sense of purpose and challenge.

TOHATU was founded in 1959, at the dawn of Japan's post-war electricity demand boom, as a company dedicated to building and maintaining the power-generation facilities of the Tohoku region. Its official history page records the publication of company histories at ten-year intervals — a 10-year history in February 1973, a 20-year history in September 1979, a 30-year history in October 1989, a 40-year history in January 2000, a 50-year history in February 2010 and a 60-year history in December 2019 — which traces a continuous institutional life from the early 1970s through the present. The 60-year history, issued in December 2019, marks the company's 60th anniversary and confirms that it has operated for more than six decades. From its base in Sendai, Miyagi Prefecture, TOHATU grew into a comprehensive engineering company within the Tohoku Electric Power Group. Its work has always been closely tied to the group's power stations: thermal, hydroelectric, nuclear and, more recently, renewable-energy plants. Over time it broadened its customer base beyond power producers to owners of factories and industrial plants, adding services for biomass-related facilities, clean centers, smelting plants, paper mills and cement plants. This diversification reflects both the maturity of Japan's power-plant construction market and the company's effort to apply its engineering and maintenance skills to adjacent heavy-industry sectors. A significant part of TOHATU's modern identity is its technical specialization. Its Rifu manufacturing plant handles piping work subject to self-inspection under Article 52 of the Electricity Business Act, covering sales, design, execution (processing), welding and inspection as an integrated chain, and the plant has been used as an evaluation-test venue by the Japan Welding Engineering Society. The company also developed a patented inspection device (Patent No. 5085115) that combines ultrasonic testing with three-dimensional coordinate measurement, producing 3D maps of defect positions and surface shapes; by the early 2020s it had accumulated more than 20 applications, mainly in Fukushima Prefecture, where the results are used to help customers decide when to renew hydro turbines. By the mid-2020s TOHATU employed 1,709 people across 32 business locations, including a technical training center and a technical development laboratory, and operated mainly in the six Tohoku prefectures plus Niigata Prefecture, with a presence in Tokyo. In fiscal 2025 it recorded 3,914 projects and sales of 73.8 billion yen, with stated capital of 1 billion yen. The company has articulated a Management Vision 2030 and aligns its sustainability activities with the Tohoku Electric Power Group Sustainability Policy, positioning itself as a long-term partner in the stable supply of electricity to Tohoku and Niigata.

• 2026

  Executive personnel changes announced (June 16, 2026); company reports 1,709 employees as of March 31, 2026.

• 2025

  Visual identity established (September 1, 2025).

• 2019

  60-year company history published (December 2019), marking the 60th anniversary.

• 2010

  50-year company history published (February 2010).

• 2000

  40-year company history published (January 2000).

• 1989

  30-year company history published (October 1989).

• 1979

  20-year company history published (September 1979).

• 1973

  10-year company history published (February 1973).

• 1959

  Company founded; begins building and maintaining power-generation facilities in the Tohoku region.

A Tohoku Electric Power Group comprehensive engineering company that builds, supports and protects power-source facilities with high technical capability, centered on the Tohoku region and Niigata.

• Thermal power plant construction and maintenance

  New construction, periodic inspection and maintenance of thermal power stations for power producers.

• Hydroelectric power plant works

  Generator replacement and related works at hydroelectric power stations.

• Nuclear power plant support works

  Engineering and maintenance support for nuclear power stations.

• Renewable energy plant works

  Construction and maintenance for renewable-energy generation facilities.

• Biomass facility works

  Periodic inspection and maintenance of woody biomass power plants and related facilities.

• Clean center facility works

  Works for waste-to-energy and clean center facilities.

• Smelting, paper and cement plant works

  Boiler periodic inspection, steam turbine inspection and related works for smelting, paper and cement plants.

• Electrical equipment installation

  Installation of electrical equipment for power and industrial facilities.

• Emergency power source installation

  Installation of emergency power sources.

• Instrumentation, control and communication works

  Instrumentation, control and communication system works.

• Turbine and boiler equipment works

  Installation and maintenance of turbine and boiler equipment.

• Boiler solutions

  Boiler-related engineering solutions including tube welding and inspection.

• Advanced welding and prefabrication

  High-grade welding for high-temperature, high-pressure, wear-resistant and corrosion-resistant steel piping, including boiler tubes for large power-generation boilers.

• Non-destructive inspection (3D-UT)

  Patented device integrating ultrasonic testing and 3D coordinate measurement to map defect positions and surface shapes.

• Concrete and civil engineering material sales

  Sale of concrete materials and civil engineering materials.

1. 1TOHATU official website homepagetohatu.co.jp
2. 2TOHATUのあゆみ｜会社案内｜TOHATU（東北発電工業株式会社）tohatu.co.jp
3. 3TOHATUとは｜TOHATU（東北発電工業株式会社）tohatu.co.jp
4. 4会社案内｜TOHATU（東北発電工業株式会社）tohatu.co.jp
5. 5Wikidata: Tohoku Electric Power Engineering And Construction Co., Inc. (Japan)wikidata.org