The Forestry Agency is considering building biomass power plants that can use timber left behind by the thousands of houses that destroyed by the massive March 11 tsunami in Tohoku.
Proponents of the idea say it aims to kill three birds with one stone — debris disposal, promotion of renewable energy, and reinvigoration of forestry — but critics are questioning the financial viability of the idea.
“Initially, wooden debris will be used for power generation and when it becomes financially viable, wood thinned from forests will be used,” Takashi Shinohara, senior vice minister of agriculture, forestry and fisheries, said at a meeting of an advisory council to the Forestry Agency on July 13.
Biomass power uses organic resources derived from animals and plants, such as thinned wood, sugar cane and livestock dung. Unlike petroleum or coal-fired power stations, it emits less carbon dioxide and there are ample supplies of fuel.
Along with solar power, it is considered a renewable or natural energy source.
The agency said the quake and tsunami generated 25 million tons of debris from houses alone, with roughly 70 percent of it wood. Even excluding waterlogged debris, there are still 5 million tons available.
One power plant typically needs around 12 tons per year for fuel. The volume of debris is “enough to fully cover fuel for several years,” said one agency official.
The agency is looking at subsidizing half of the cost of building such facilities at about five locations in the disaster-hit area. It is hoping to secure around ¥10 billion in appropriations in the third supplementary budget for the current fiscal year.
But Miyuki Tomari of the Biomass Industrial Society Network, a nonprofit group, said, “It’s good so long as there is debris, but that is after all a stopgap (material).”
Her comment reflects the situation of timber-based biomass plants, which numbered 144 throughout the country in a 2008 survey by the Internal Affairs and Communications Ministry.
“Many are struggling after having failed to eke out a profit,” said Tomari.
Spikes in the prices of petroleum and coal around 2008 prompted many manufacturing plants to switch to biomass for their in-house power generation facilities. This pushed up the costs of construction and demolition debris used as fuel.
Much of the thinned wood in forests is left where it falls. An operator of a biomass plant said, “Transport out (of the forests) poses problems and is costly, so it does not pay to use it as fuel for a power plant.”
Kenichiro Kojima, executive director of the Pellet Club, which promotes the use of natural energy sources, said: “Power generation alone will never be profitable. Efforts should also be made to make use of residual heat.”
The Forestry Agency for its part is considering building five plants adjacent to timber processing factories, including those slated for reconstruction from the tsunami.
The agency is hoping to provide not just electricity but also supply homes with water heated by residual heat or cooled by vaporization, as well as for freezing and refrigeration at fish processing factories.
On the feasibility of timber-based biomass power generation and heat supply, Minoru Kumazaki, a scholar of forest resources management, said, “Conditions are beginning to be laid out to make it feasible, such as legislation for having power companies buy electricity generated with renewable energy sources, which is being deliberated in the Diet.
“It’s also necessary for the state to take more comprehensive measures such as building roads in mountain areas in order to bring down the cost of logging and delivering thinned wood from forests,” said Kumazaki, professor emeritus of Tsukuba University.