**1. Introduction**

*1.1. Background*

Carbon neutrality, the goal of achieving virtually zero greenhouse gas emissions in the wake of the Paris Agreement adopted in 2015, is now a global trend. A total of 128 countries and self-governing territories have declared their intention to pursue this goal [1]. Climaterelated actions are currently being implemented to achieve this. Expectations for renewable energy are growing, and the use of woody biomass is expected to increase.

Meanwhile, the Joint Research Center, designated by the European Commission, published a research report titled "Use of Forest Biomass in EU Energy Production" [2]. The report stated that "The reconstructed Renewable Energy Directive (REDII Directive 2018/2001) envisages zero emissions at the point of biomass combustion. Bioenergy is not accounted for in the energy sector because these emissions are already counted as a change in carbon storage in the land use, land-use change, and forestry (LULUCF) sector (Regulation 2018/841). Therefore, the assumption that bioenergy is 'carbon neutral' within the broader EU climate and energy framework is incorrect" [2] (p. 9).

The above view is quite different from the theory that trees have CO2 fixed in their trunks until they are cut down; therefore, even if trees are cut down and burned, and CO2 is generated, they are carbon neutral if they are repeatedly managed and planted. Furthermore, the report points out that forests are being cut down for fuel procurement, which threatens ecosystems and biodiversity. There is a need to balance woody biomass

**Citation:** Fujino, M.; Hashimoto, M. Economic and Environmental Analysis of Woody Biomass Power Generation Using Forest Residues and Demolition Debris in Japan without Assuming Carbon Neutrality. *Forests* **2023**, *14*, 148. https:// doi.org/10.3390/f14010148

Academic Editors: Noriko Sato and Tetsuhiko Yoshimura

Received: 24 December 2022 Accepted: 11 January 2023 Published: 12 January 2023

**Copyright:** © 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).

power generation with ecosystems and biodiversity. Thus, the situation surrounding forest biomass is changing drastically.

The Japanese Government has been working to promote renewable energy since the Fukushima Daiichi Nuclear Power Plant accident on 11 March 2011. For example, a feed-in tariff (FIT) system was introduced in July 2012. Renewable energies include solar, wind, hydro, geothermal, and woody biomass, which is a unique energy source. Solar and wind energy are public goods, but woody biomass is a private good. Therefore, when electric power companies purchase this resource, they contribute to the local economy, especially the forestry industry. As such, many forest owners, conduits, and administrators in Japan expect significant economic benefits from woody biomass use. However, power generation using this resource increases CO2 emissions. Hence, assuming that forest biomass is not carbon neutral, this study determined where and how much economic benefit and where and how much CO2 emission or reduction can be achieved through forest biomass power generation in Japan. Specifically, this study evaluated the economic and environmental effects of woody biomass power generation during construction and operation through an inter-industry analysis using workplace data from the Gifu Biomass Power Co., Ltd. (GBP), a woody biomass power generation company in Gifu Prefecture. The data used in this study were from the first year of operation (2016). Data for subsequent years were unavailable when this study was conducted, and the projections may differ from actual measurements.

#### *1.2. Current Status of Woody Biomass Power Generation in Japan*

Japan is one of the most forested countries in the world. Forests cover approximately 25 million hectares, or 2/3, of the country's land area. Plantation forests account for 40% of this total, or 10 million hectares. The forest stock, mainly planted forests, has increased by approximately 70 million m<sup>3</sup> annually and currently stands at approximately 5.2 billion m3. Planted forests are coniferous, with cedar and cypress species. Most of these trees were planted after 1945 for building materials, and when the trees reach 30 years of age or more, they are thinned once every ten years or so, with clear cutting occurring after 50 to 60 years. However, steep slopes, intricate contour lines, and heavy precipitation make it difficult to create a road network. Even if overhead wires are used, the small working area causes inefficiencies. Hence, the cost of collecting timber is high, leaving a large amount of timber in the forest.

With the shift to renewable energy being a global trend and Japan having the motive to get rid of nuclear power, thinned wood and forest residues are being used as woody biomass. Woody biomass is burned to generate electricity, with little or no use for the heat produced. To promote the use of woody biomass for power generation, a FIT system was introduced based on the German model (see [3]). The price for electricity generated by woody biomass power plants was determined in 2012 and varied depending on the type of fuel. The price for unused wood was set at 33.6 JPY (including tax); general wood, such as sawmill scraps and palm coconut shells, was at 25.2 JPY; and wood derived from construction materials at 13.65 JPY [4]. Since then, the price has been revised several times. In contrast to government policy that aims to promote the use of unused wood, many woody biomass power plants import and use palm coconut shells from Southeast Asia as raw materials [5].
