Renewable Energy Institute (REI) provides data on fuel consumption of solid biomass such as woody biomass and palm kernel shell (PKS), which are obtained by combining several statistical sources1. The chart below is developed by using the Forestry Agency's "Woody Biomass Energy Consumption Survey" and includes data on the amount of black liquor used, which is prepared by the Japan Paper Association, as well as data on imported biomass (PKS and wood pellets), which can be obtained from trade statistics. It therefore compiles different data in order to show the overall picture of solid biomass fuel deployment in Japan.
Fig.1 Solid Biomass Consumption in Japan (million dry-ton)
Note: To convert to dry-ton, water contents were used for wood pellet (15%) and PKS (20%). For black liquor, high heating value (13.2GJ/dry-ton) was used to convert to the mass unit. Imported wood chip includes chip produced from imported log.
Sources: Domestic biomass：Forest Agency, Woody Bioenergy Consumption Survey (accessed in October 2021). Imported biomass: Trade Statistics (HS code: wood pellet:440131000, PKS：230660000 and 140490200). Black liquor: Japan Paper Association, Energy Report of Pulp and Paper Industry (The figure of 2020 was estimated with the paper and paperboard production)
Development status until 2020
Since 2015, the use of solid biomass fuels has been consistently increasing at a rate of 4-8% every year, exceeding 25 million tons (hereafter, on an absolute dry basis) for the first time in 2020. The largest growth is seen in "thinned wood and forest residues" which more than tripled from 2015 to 2020, reaching 3.9 million tons in 2020. In addition, the use of imported wood pellets and PKS also increased significantly, to 1.63 million tons and 2.85 million tons, respectively, in 2020. The increase in these three types of fuels can be attributed to the increase in the number of power plants under the feed-in tariff (FiT) scheme.
On the other hand, black liquor and waste wood (demolition materials and scrap wood) continue to account for the majority of the biomass, although the amount used remains unchanged, at 10.03 million tons and 4.17 million tons respectively in 2020. Black liquor is used for cogeneration of heat and electricity at paper mills, but it is fair to say that it is underestimated in terms of energy policy because it is categorized as auto production. Woody construction material waste was the main biomass power generation fuel under the renewable portfolio standard (RPS) system before the FiT, and it is important in that it can generate power at low cost.
If we add lumber remnants and other woody biomass such as landscape caring, thinned wood and forest residues, and wood pellets (domestically produced), we can see that about 80% of the total biomass is domestically produced from waste and residual streams. Therefore, it is not accurate to say that imported biomass accounts for most of the biomass. However, if we look at raw materials, the self-sufficiency rate of feedstock in paper industry remains about 30%, and that in sawmills is about 50%. The same problem applies to biomass derived from agricultural products (livestock and animal manure, food waste), which are imported in large quantities, and can be considered to be a problem of Japan's primary industry.
Issues to be improved in the statistical data
The energy use of wood is also supplemented in the Ministry of Economy, Trade and Industry (METI)’s Total Energy Statistics. However, there are some discrepancies between the figures in the Forestry Agency statistics and the Total Energy Statistics. In addition, the former is based on calendar years while the latter is based on fiscal years, so a simple comparison cannot be made in the first place, but here is a comparison of the two figures converted into energy units based on 2019 (Figure 2).
Fig. 2: Comparison of the Total Energy Statistics and aggregated figures by REI
First of all, the total amount of utilization is 411.2 PJ in the Total Energy Statistics2, which is consistent with the 420 PJ in the aggregate results by REI. However, there are many areas where the breakdown does not match, as shown below, and it would be desirable to clarify the correspondence.
Indeed, the 99.2 EJ of wood use in the Total Energy Statistics is nearly consistent with the total value (93.6 EJ) of thinned wood and forest residue (59.8 PJ) and sawn wood (33.8 EJ) from the Forestry Agency. On the other hand, there is a nearly two-fold gap between the 41.2 PJ of waste wood use in the Total Energy Statistics and the 80.2 PJ of construction material waste in the Forestry Agency statistics. However, in the Total Energy Statistics, the item " other biomass" has a large amount of 108.8 PJ, which may include construction material waste in the Forestry Agency statistics in addition to PKS. There is also a difference of about 10 PJ for black liquor, which seems to have a relatively small number of facilities captured.
Finally, as for imported biomass fuels, wood pellets and PKS can be monitored by trade statistics because the corresponding HS codes can be identified. However, if new fuels, such as coconut shells, are approved and used under the FIT system, it would be difficult to track the consumption development from trade statistics. Therefore, it is necessary to develop a system to directly collect, organize, and publish fuel data from power plants.
