Illustrator Hiroki Tsuboi visits Sumitomo Group
Sakata Biomass Power Plant, Summit Sakata Power Corporation

This 50MW biomass power plant located adjacent to Sakata North Port on the Sea of Japan,
is one of the Tohoku region’s largest.
Commercial operation began in August 2018.

Summit Sakata Power Corporation
  • Sakata Biomass Power Plant, Summit Sakata Power Corporation

Biomass power generation is a type of renewable power generation. This plant uses wood chips and pellets made of tree tops and thinnings as fuel. This type of gentle-on-the-environment power generation has a special fascination for me, maybe because my 4-person household, with me spending my days working at home on my computer, is so dependent on electricity.

Located in Sakata City, Yamagata Prefecture, Summit Sakata Power’s 50MW biomass power plant is one of the largest of its kind in the Tohoku region. It consumes 160,000 tons of wood chips sourced in Japan and 100,000 tons of imported wood pellets each year. The wood chips, which account for 40% of the power generated, come from Yamagata Prefecture. So the plant contributes to the local forestry sector. The wood pellets are shipped from Canada every two months. Up to 29,600 tons of wood pellets (enough for about 2.5 months) are stored in a warehouse at the wharf across from the plant. Wood pellets are trucked from the warehouse to the plant every day.

The plant has three main buildings: a building for receiving biomass fuel, a boiler building for generating steam, and a turbine building for generating power.

power generation

Everything necessary for power generation—the boiler, turbines, biomass reception facility, etc.—is laid out on the extensive 45,000m2 site.

Inside the pellet warehouse

Inside the pellet warehouse. Some 25 truckloads of wood pellets per day, amounting to 300 tons, are delivered to the power plant.

Solid fuel pellets of compressed sawdust.
3 3
The truck dumper tilts a truck, tipping 20 tons of wood chips into the hopper.

Wow! A huge quantity of wood-chip biomass fuel flows into the system!

Wow! A huge quantity of wood-chip biomass fuel flows into the system!

Wood chips and wood pellets are transported from the fuel building to tanks and then supplied to the boiler building. The most impressive sight was the unloading of 20 tons of wood chips from a truck into a hopper (see photo 1-3). A truck dumper tilts the huge truck 50 degrees! All the wood chips in the container are unloaded in one go. It took just a couple of minutes. Once biomass fuel is supplied to the boiler building, the power generation process starts.

Biomass power generation system

Biomass power generation system

The fuel, wood chips made of logging residue sourced in Japan, is fed into the circulating fluidized bed boiler. Air is blown into the boiler from the bottom for efficient combustion. The heat generated boils water to produce steam to drive the turbine to generate power.

This is how power is generated!
The boiler piping looks like a maze!

The boiler piping looks like a maze!

Stepping into the boiler building, I am confronted by a gigantic 45-meter-tall circulating fluidized bed boiler. The temperature inside the boiler rises to about 890ºC during combustion. Because thermal expansion causes its dimensions to increase by about 20cm, it is installed in such a way that it never comes into contact with any of the adjacent pipes. The profusion of pipes routed around the boiler also caught my eye (see photo 4). Fuel is supplied to the boiler through several pipes. A jet of air entering from the bottom of the boiler mixes the fuel with high-temperature silica sand to ensure efficient combustion. Steam generated by the boiler turns the turbine blades and the generator connected to the turbine turns to generate power.

As if following the steam, we proceed to the turbine building. At the center of a spacious chamber, a steam turbine and a generator are installed. Compared with the enormous boiler, they are quite modest in scale. Considering the size of the boiler and the amount of fuel used to turn this turbine, I can appreciate the technical challenge of power generation. While grateful for a plentiful supply of electricity, reflecting on the environmental impact, I am hoping renewables will account for an ever-greater share of the electricity generated.

Wind turbines and solar panels

Wind turbines and solar panels alongside the biomass power plant.

Panoramic view from the top of the boiler building! 50 meters up!
What is most important? Communication!

During my visit, I was delighted to have an opportunity to interview Mr. Masamichi Takase, President of Summit Sakata Power, who accords prime importance to people. The central control room includes a stylish cafe for those working at the plant. To keep the plant running 24/7, the workforce is divided into three shifts. As the work can be intense, he emphasizes the need to relax during breaks. To ensure safety, in addition to “hard” measures, such as safety equipment, “soft” measures are thoroughly inculcated through safety education as well as a daily morning gathering at 8:00 in which everyone on the shift participates. Mr. Takase stresses the importance of the quality of communication. For example, encouraging employees to exchange greetings is beneficial in terms of security. Moreover, in the office the president’s desk is near the desk of the engineering manager and those of other managers to facilitate swift sharing of issues and quick decision-making.

Mr. Takase also emphasizes the importance of hiring local people. Of the 26 employees, 20 were recruited locally or are people who returned to Yamagata Prefecture after a spell elsewhere. Since none of them had any experience of operating a power plant, Mr. Takase spent two years on HR development before the plant entered full-scale operation. Employing local people makes a valuable contribution to the community. Mr. Takase often meets with people working in the local forestry sector, who are the suppliers of wood chips, and frequently briefs local residents on activities at the plant. He says that creating opportunities for communication and facilitating understanding when everything is going smoothly creates a stock of goodwill, which can ensure cooperation and support for the company in the event of any eventuality. The wall art on the pellet warehouse, “WELCOME TO SAKATA,” extends the hand of friendship to those on cruise ships visiting Sakata Port and encourages fruitful exchanges among people.

Mr. Takase is a talented individual who has demonstrated his ingenuity in the branding of the company. Summit Sakata Power’s website has many video clips, including several Mr. Takase shot using a drone. Just by watching the video clips, you can get a good understanding of this biomass power plant. The target audience is not limited to the general public. With a view to stimulating fruitful discussion, he would like people in the same industry to watch the video clips before meetings. After my interview, Mr. Takase’s schedule included interviews with prospective employees followed by a briefing for local residents that evening.

Listening to Mr. Takase, not only was the importance of communication both inside and outside the company impressed on my mind, but I also refreshed my recognition of the significance of the ongoing shift to renewable energy.

Branding is important for a power plant, too!

President Takase is good at branding! He uses a drone to shoot video clips for the website.
Stylish cafe!
WELCOME TO SAKATA” wall art! I’ll do the same!
At my home-cum-office My children have come to play…

Editor’s note

Ever since the selection of Summit Sakata Power as our next destination, Mr. Tsuboi had been excited at the prospect of seeing the inside of a biomass power plant. Indeed, all of us were keenly anticipating the visit.

As Mr. Tsuboi describes in his article, we were all struck by the extraordinary quantity of wood chips needed to fuel the massive circulating fluidized bed boiler that keeps the generator running at full tilt.

On the return journey following the visit to the plant, Mr. Tsuboi commented that he was as impressed by the people involved in the operation as he was by the power generation system itself. “The operators, many of whom are recruited locally, show outstanding commitment to environmentally friendly power generation. Mr. Takase, president of Summit Sakata Power, offers inspiring leadership. Individuals and businesses in the region are happy users of the green electricity. What’s more, the plant occupies a special place in the affections of people in the community, enjoying the wholehearted support of local companies and local residents alike. Mr. Takase and his team reach out to stakeholders, communicating with them so as to cultivate fruitful relationships.”

In fact, to help us accurately present the biomass power generation system in illustrations and text, Mr. Takase kindly let the interview continue for an extra 30 minutes, despite having another appointment immediately afterward. He explained the system in detail until we had a good grasp of it. Mr. Takase’s enthusiasm for the plant was evident and we are grateful to him for sharing his time and knowledge with us.

A truck fully loaded with wood chips heads for the hopper.
A truck fully loaded with wood chips heads for the hopper.
Mr. Tsuboi sketches the idea for an illustration while standing next to the boiler piping.
Mr. Tsuboi sketches the idea for an illustration while standing next to the boiler piping.
The 50MW-class steam turbine and the power generator.
The 50MW-class steam turbine and the power generator.

Number (Manga Reportage "Visits to Sumitomo Group")