Are you familiar with biomass power generation?
It is one of the renewable energy sources that the Ministry of Economy, Trade and Industry and the Ministry of the Environment are strongly promoting, and it has become one of the leading energy sources following solar, wind, hydro, and geothermal power.
In this article, I would like to provide a detailed explanation of biomass power generation, a topic that I have personally long questioned regarding its usefulness from both an environmental (eco) and social perspective.
*The author is neither a stakeholder nor an opponent of biomass power generation, nor a fervent supporter of environmental measures; simply an ordinary person.
What is renewable energy?
Before explaining biomass power generation, let's briefly review renewable energy.
Renewable energy is a general term for power generation (and heat utilization) that uses energy sources that are continuously supplied in nature, such as sunlight, wind, geothermal energy, water flow, and plants. Unlike fossil fuels (coal, oil, and natural gas), it is characterized by the fact that its resources are less likely to be depleted.
However, the word "renewable" does not mean "energy is regenerated." It seems to mean that because it utilizes input sources that are continuously supplied within the scope of natural cycles (solar, wind, water cycle, geothermal energy, and the biological cycles of plants and animals), it is regenerated even after being used as energy.
- Less susceptible to fluctuations in fuel costs: Solar and wind power, in particular, do not require fuel.
• Low CO2 emissions during operation: This can make a significant difference over the entire lifecycle.
- It can be treated as a domestic resource: It has the potential to contribute to energy security.
Given these advantages, the Japanese government is strongly promoting the spread of renewable energy, with a focus on reducing CO₂ emissions and ensuring energy security (with a budget of approximately 4000 billion yen projected for 2025, which exceeds 1 trillion yen including taxes and government debt obligations).
Among renewable energy sources, biomass power generation is attracting attention because it is easier to handle and provides stable power generation compared to solar, wind, and geothermal power, as it primarily utilizes plants (biological cycle of biomass).
How biomass power generation works
Here, we will briefly explain how biomass power generation works.
Fuel sources used in biomass power generation can be broadly categorized into three types: underutilized resources, waste, and specialized crops (see the diagram below).
Industrial waste is mainly used for waste-to-energy generation, and food and livestock waste is used for gasification power generation (methane gas), but the amount of electricity generated is relatively small. The main source of power generation is biomass power from unused plant-derived and resource crops.
In Japan in particular, wood-based biomass fuel derived from palm oil, used in forestry and oil production, is the main type of biomass fuel.
The main mechanism of biomass power generation is as follows:
Biomass fuel is burned to boil water, and the resulting steam rotates a turbine. The rotational force of the turbine drives a generator, producing electricity.
As you can see from the diagram above, the mechanism is basically very similar to existing thermal power generation (coal and oil).
Because it is a power generation method that can utilize existing technologies, it is easy to introduce and operate, and since it is a combustion-based power generation system, it can provide a stable power supply.
However, unlike fossil fuels such as coal and oil, biomass fuels are derived from plants and animals and are very difficult to burn, so they require processing to make them easier to burn (pelletization).
This pelletizing process is surprisingly difficult and is one of the key technologies in biomass power generation.
To solve the problems described above, the pellets are produced through the processing steps shown in the following diagram.
This pelletizing process transforms biomass into a more easily combustible fuel, enabling stable power generation.
The basis for calling biomass power generation eco-friendly
Actual biomass power plants, as you can see from the photo, are equipped with chimneys. Because they use a combustion-based power generation method, they produce smoke, and that smoke naturally contains CO₂.
The reason why it's still considered eco-friendly is based on the following idea.
Biomass fuels are basically plants. Before being used as fuel at a power plant, plants absorb CO₂ through photosynthesis. By subtracting the amount of CO₂ absorbed during power generation from the CO₂ emissions, the CO₂ emissions are considered to be zero.
In other words, it is possible to achieve zero CO₂ emissions while using conventional combustion-based power generation technology, thus enabling stable power generation. Due to these characteristics, biomass power generation is positioned as one of the important pillars of renewable energy.
The reality of biomass power generation
Up to this point, I've explained general biomass power generation, but from here on, I'll fully embrace the kazubara.net style and explain the problems from an engineering perspective.
1. The collapse of the carbon neutrality theory
Government and general explanations state that CO₂ absorption and emissions from biomass fuel and power generation cancel each other out.
However, the conditions under which this "net zero" holds true are precisely where major misunderstandings arise. In reality, only the combustion of the biomass used as fuel balances out the amount of photosynthesis performed by the plants that serve as fuel.
This equation only holds true under ideal combustion and photosynthesis conditions, and other factors are completely irrelevant (power generation is irrelevant, only combustion). In reality, neither combustion nor photosynthesis proceeds ideally (complete combustion, variations in the amount of photosynthesis during plant growth, etc.).
Therefore, the CO₂ emitted during the cultivation, harvesting, transportation, and processing (pelletization) of plants used in biomass power generation is entirely additional.
* During forest growth, CO2 is generated through the decomposition of dead leaves, dead branches, and roots, as well as soil respiration.
While efforts are being made to improve efficiency and electrify the entire process, the electrification of machinery is progressing slowly because the wood that forms the basis of biomass is located in mountainous areas and the cultivated crops are located on farmland.
Ultimately, we will have to rely on conventional fossil fuel-derived energy. In particular, imported biomass fuel will have to be transported by sea, making electrification virtually impossible and inevitably resulting in CO2 emissions.
In other words, the more biomass power generation is done, the more CO₂ is emitted because CO₂-absorbing plants are cultivated, harvested, transported, and processed in ways that generate CO₂.
I'm not a fervent supporter of environmental issues, but when people talk so much about "carbon-neutral and clean energy," I feel a strong sense of unease because it's so far removed from reality.
The fact that plants absorbed CO₂ is a thing of the past. Global warming countermeasures address the current and future levels of CO₂, so I question the practice of burning wood and other plants, which releases CO₂.
2. Extremely poor power generation efficiency
Here, let's focus on power generation efficiency.
The typical power generation efficiency of biomass power plants is around 20% for small and medium-sized plants, and a very low 25% for large-scale plants (power generation efficiency is the ratio of input energy to power generation, and input energy can be considered roughly the same as the amount of fuel).
In addition to this poor power generation efficiency, pelletizing, which is a necessary pretreatment for biomass fuel, is essential, so the actual power generation efficiency is lower than 20-25% (if pelletizing is done efficiently at the same facility, additional energy is required if pelletizing is done at a separate facility).
Rough calculations show that pelletizing consumes approximately 165 kWh, resulting in a net power generation of 835 kWh (per ton of pellets). This means the power generation efficiency drops to between 16.5% and 21.5%.
Comparing the efficiency of fossil fuel-based power generation methods, thermal power generation is approximately 40%, state-of-the-art natural gas power generation is over 60%, and coal power generation is 48-50%, meaning that biomass power generation is less than half as efficient.
In other words, to obtain the same amount of electricity, biomass power generation requires approximately twice the amount of fuel compared to thermal power generation, approximately three times the amount compared to natural gas, and about 2.5 times the amount compared to coal.
This increase in required fuel directly translates to higher costs. For example, if we use the average domestic procurement costs for each fuel in 2025 as a basis for a rough calculation of the price per 1000kWh, it would look like this:
Per kWh, the fuel cost for biomass power generation is 47.7 yen, for thermal power generation it's 23.1 yen, for natural gas it's 11.1 yen, and for coal it's 7.2 yen (actual electricity costs are higher because they include facility depreciation and personnel costs, so these are reference values).
The high cost of electricity generated from biomass is compensated for by a renewable energy surcharge (currently about 4 yen/kWh) which is added to our electricity bills (the highest amount ever, expected from May 2025).
*The renewable energy surcharge is a subsidy for all renewable energy generation, so not all of the approximately 4 yen/kWh is used for biomass power generation.
*This system collects money from renewable energy sources, which have a lower power output, by collecting a flat rate of approximately 4 yen/kWh for all power generation (renewable energy accounts for around 26%, and biomass power accounts for 5.9% of total electricity generation, according to 2024 statistics).
Leaving aside the financial aspect for a moment, a larger amount of fuel required for power generation means a larger amount of CO2 emissions (determined by the carbon content of the fuel and the amount of fuel used).
Compared to coal, which is said to emit a lot of CO2, this fuel produces more than 2.5 times the amount of CO2 (this is a theoretical calculation, but it should be fairly accurate).
Even if the biomass fuel has absorbed CO2 in the past, I don't understand the logic behind releasing a large amount of CO2 again.
Personally, I don't understand the logic behind adding large amounts of CO2 to the atmosphere through biomass power generation, because I believe global warming is a problem for the present and the future, regardless of how much CO2 was absorbed in the past (CO2 simply increases; burned plants don't grow back immediately).
3. The Reality of Fuel Procurement (The Reality of the Supply Chain)
When biomass power generation is described as a "clean renewable energy source," it is always accompanied by discussions about "utilizing unused domestic thinned timber" and "regional revitalization and improving energy self-sufficiency," but in reality, these efforts do not seem to be going very well.
67% of Japan's land area is covered in forests, but not all trees are suitable for use as biomass.
Half of the forest land is unusable for environmental protection, landslide prevention, water source protection, etc.
• High-quality timber is used for construction.
General lumber is used for plywood and furniture.
Considering these factors, the amount of timber suitable for use as biomass fuel is limited (because young trees need to be allowed to grow).
Furthermore, much of Japan's forests are located on steep slopes far from human settlements, making logging and transportation costs high. As a result, the amount of usable timber decreases from both a technical and economic standpoint (this is compensated for by taxes such as renewable energy surcharges, forest environment taxes, and forestry subsidies).
Given these circumstances, even with a generous estimate, only about 10% of the wood is suitable for biomass power generation.
In reality, the current supply is nowhere near enough to keep the existing 244 biomass power plants running at a steady pace (from an engineering and economic standpoint, we want to maintain continuous operation of biomass power plants).
*The 244 locations are based on a 2025 report from the Ministry of Economy, Trade and Industry.
The reality is that the shortfall is covered by imports (according to 2024 statistics).
Breakdown of imports
The reality is that only 36.8% of electricity needs are met domestically. Looking at the proportion on a power generation basis, the self-sufficiency rate would be even lower because PKS (palm kernel shells), which is 100% imported, is highly flammable and has a high energy content (palm kernels are rich in oil and highly flammable).
Of course, imported biomass fuels are also subject to tax subsidies through the FIT/FIP system (compensated by renewable energy surcharges; the system itself is complex so I will omit the explanation).
Is it just my imagination, or are the supposed advantages of bio-power generation, such as "utilizing unused domestic thinned timber" and "regional revitalization and improving energy self-sufficiency," far removed from reality?
The current situation regarding the import of biomass fuel
Up to this point, we've looked at biomass power generation from the perspectives of CO2 emissions as a measure against global warming, efficiency, and procurement. Now, let's look at the production situation in the importing countries.
This article contains some sensational content, but it will be based on facts (for some reason, there is little media coverage of this in Japan).
Based on the importing countries explained in the diagram earlier, we will now explain the process by dividing it into three regions: the United States and Canada (wood pellets), Indonesia and Malaysia (PKS: palm kernel shells), and Vietnam (wood pellets).
1. United States and Canada
220 million tons of high-quality wood pellets are imported from this region, accounting for about 12% of Japan's total biomass fuel supply.
The main production locations are British Columbia in Canada, and South Carolina and Georgia in the United States.
What's happening here is that old-growth forests are being illegally cut down, and some of the wood is being exported as wood pellets for biofuel.
Basically, agreements are in place to prevent the indiscriminate logging of wood for biomass fuel (laws of each country, private certifications such as FSC/PEFC and SBP, and in Japan, the Clean Wood Act).
There are various rules, but basically, in order to maintain sustainability, logging of old-growth forests is prohibited, and thinned timber and waste wood are reserved for use as biomass fuel.
However, in reality, the following actions are occurring (representative examples are listed below):
1. Turning whole logs from old-growth forests into wood chips while reporting them as waste and thinned timber.
While the process should have used only waste materials (such as sawmill residue) and thinned timber, in reality, huge logs (raw timber) cut from old-growth forests with high carbon storage capacity were being fed directly into the chipper and pelletized.
Sources: Mongabay (2022-2023), BBC Panorama (2022/2024), etc.
2. Illegal logging of old-growth forests
In British Columbia, Canada, logging is being carried out by a company in an "old tree sanctuary" that the provincial government had designated for protection.
Sources: Stand.earth (2025 latest report “Truckloads of Trees”), The Guardian (2025), etc.
3. Illegal laundering of certification systems
They are mixing uncertified "black (illegally logged) timber" with certified "white (clean) timber" and shipping it out.
Sources: Ofgem (published in 2024), FCA (Financial Conduct Authority), etc.
While illegal businesses exist to some extent in any industry, in the case of biomass fuel, the industry's largest company was caught engaging in fraudulent practices, was indicted, and subsequently sanctioned, making it a very large-scale problem.
- The lie about using waste materials was exposed, leading to a lawsuit from investors.
- Inappropriate accounting practices and greenwashing (environmental misrepresentation) that does not reflect actual circumstances have been pointed out.
As a result, the company filed for Chapter 11 bankruptcy in March 2024, effectively going bankrupt (this has a slightly different meaning than bankruptcy in Japan).
- BBC Panorama's accusation of illegal logging has become a political issue in the UK.
In August 2024, the UK's energy regulator (Ofgem) ordered the company to pay a massive £25 million (approximately 48 billion yen) in contributions (effectively a penalty) for serious deficiencies in its supply chain data reporting.
Unfortunately, just because it's an overseas company doesn't mean it's unrelated to Japan; in fact, it partners with major trading companies to import large quantities of wood pellets (although Enviva is effectively bankrupt, it continues to supply products due to long-term contracts with several major Japanese trading companies).
While this might be a slightly extreme statement, it wouldn't be wrong to say that a portion of our tax money is being misused, so it's difficult to say that this situation is completely unrelated to us.
2. Indonesia and Malaysia
We import large quantities of PKS (palm kernel shells) from Indonesia and Malaysia (587 million tons). This accounts for about 30% of Japan's total biomass fuel supply.
Surprisingly, 91% of Indonesia's total PKS (palm kernel shell) exports and 99% of Malaysia's total PKS exports are destined for Japan (according to trade statistics).
Unfortunately, many cases of fraud are occurring in this region as well.
1. Arson in peatlands.
The Indonesian government has put forward a moratorium on the development of peatlands (carbon deposits), but because clearing them with heavy machinery is costly, the mafia and some businesses intentionally burn down forests to develop the land (releasing large amounts of CO2). Palm trees are then planted on the burnt land, cut down, and shipped.
Sources: Rainforest Action Network (RAN)'s "Keep Forests Standing" (2023-2024), FoE Japan (international environmental NGO), etc.
2. Child labor and slave labor issues
It has been reported that children aged 5 to 14 are forced into harsh labor, and that foreign workers are forced into labor after their passports are confiscated.
Sources: Amnesty International's "The Great Palm Oil Scandal" (2016), AP's "Fruits of Labor" (2020), U.S. Department of Labor's List of Goods Produced by Child Labor or Forced Labor, etc.
3. Unauthorized logging (illegal logging)
There have been reports of people illegally cutting down trees in national parks and protected areas and converting them into palm oil plantations.
Sources: Global Witness's The Shadow Trade, etc.
4. Legalization of land grabbing
In collusion with corrupt officials, land inhabited by indigenous peoples for generations has been reclassified as "unused government-owned land" and sold off to corporations, with reports of violence against residents also emerging.
Sources: Human Rights Watch's "When We Lost the Forest, We Lost Everything" (2019), Walhi, etc.
5. Shifting responsibility through shell companies (paper companies)
It has been reported that illegal or gray-area work, such as burning down forests, was outsourced to a separate company (a shell company), and then large corporations acquired the land afterward.
Sources: The Gecko Project's Indonesia's Timber Mafia, Chain Reaction Research (CRR), etc.
These problems are not limited to a few companies in the Indonesian and Malaysian regions, but are very likely to be widespread, as evidenced by incidents like the following.
- Surya Dharmadi, owner of major palm oil company Duta Palma Group, illegally converted 37,000 hectares of protected forest in Riau province (approximately six times the area inside Tokyo's Yamanote Line) into palm oil plantations.
- The head of the Indonesian Ministry of Trade's Foreign Trade Department was arrested for allegedly providing preferential treatment to certain major palm oil companies (Wilmar Group, Musim Mas, etc.) and illegally issuing export licenses.
- Sime Darby and FGV Holdings, giants in Malaysia's palm oil and biomass industry, have been specifically named by the US government, which has issued a Worker's Order (WRO) ban on imports due to evidence of forced labor (debt labor, passport confiscation, physical and sexual violence).
If it were simply fraud or falsification of environmental certifications, it would just be a matter of money, but I think it would be quite difficult to escape criticism when there are humanitarian aspects involved.
In reality, over 9% of the PKS (palm kernel shells) exported from this region are destined for Japan, so it's quite difficult to say that it's completely unrelated (the painful truth is that taxes and renewable energy surcharges are being used to fund it).
Unfortunately, it's true that we contribute to a large portion of their funding.
3. Vietnam Region
The last region I will discuss is Vietnam, Japan's largest trading partner for wood pellets (accounting for 53% of Japan's total wood pellet imports, or 308 million tons).
60% of Vietnam's wood pellet exports go to Japan, making it naturally their number one export destination (South Korea is second).
Unfortunately, illegal activities related to wood pellets are also occurring in Vietnam.
1. Fraudulent claims of sustainable forest certification (including fraudulent claims of FSC certification for sustainable forests in Japan)
Vietnam's FSC-certified forests (sustainable forests) account for only **5.6% (approximately 26 hectares) of its total planted forests, yet the amount exported far exceeds this figure, which doesn't add up.
Source: News reports from various media outlets regarding the FSC fraud case involving two companies, including AVP, Vietnam's largest wood pellet company.
2. Illegal timber smuggling from Cambodia and Laos
The majority of the timber exceeding the FSC certification limits is illegally cut down and smuggled from neighboring Cambodia and Laos. There have been reports of environmental activists and journalists who tried to stop illegal logging in national parks being eliminated by the mafia or colluding security forces.
Source: Rubberized (2024) by the international NGO EIA (Environmental Investigation Agency), etc.
3. Illegal land expropriation
Corporations, in cooperation with governments, are semi-forcibly converting land that has been used by indigenous peoples and small-scale farmers for generations into "industrial plantations (acacia, etc.)," and violence has been reported during these forced evictions.
Sources include Human Rights Watch and the local environmental forum Walhi.
These fraudulent activities, as in other regions, are not limited to a few companies or businesses, but large-scale fraud involving Vietnam's largest company has been uncovered.
- He was permanently banned (blocked) by the FSC (a sustainable forest certification body) for forging purchase invoices to make it appear as though he had bought timber from a certified company.de
- Some estimates suggest that this fraud resulted in approximately 100 to 160 billion yen in improper payments annually from Japan's renewable energy surcharge.
AVP was subsequently given a 3.5-year block, but was granted an early lifting of the ban (reinstatement) just one year later in December 2023 (has the fraud issue really been resolved?).
In August 2025, the FSC and ASI (auditing body) reportedly completed a TV loop (a verification of trade information) in Vietnam and recommended blocking (suspending) three new certified companies (an example that illustrates the deep-rooted nature of fraud in Vietnam).
Unfortunately, it is a fact that a large amount of Japanese taxpayers' money and renewable energy surcharges have been used to support large-scale fraud, including that of AVP.
Japan appears to be considering excluding wood pellets from its Feed-in Tariff (FIT) program, but what will actually happen? (This is being written in December 2025, so what about 2026?)
While a review of the Feed-in Tariff (FIT) system is underway, a transition to a Feed-in Premium (FIP) system is also being considered. In any case, subsidies will still be provided from taxes and renewable energy surcharges (although the amount of the subsidy is expected to decrease).
Summary
Up to this point, we have examined biomass power generation from an engineering perspective, looking at environmental performance, efficiency, fuel supply chain challenges, and issues related to import sources.
• Carbon neutrality in biomass power generation is achieved only through combustion and photosynthesis; all other processes emit CO2.
Biomass power generation is inefficient and has high generation costs, which are compensated for by renewable energy surcharges.
• When generating electricity, it emits more CO2 than conventional fossil fuels.However,(The plants that serve as fuel have absorbed it in the past.)
- It is difficult to meet the domestic needs for biomass fuel procurement, so we rely on imports, and the import costs are subsidized by the renewable energy surcharge.
From an engineering standpoint, I personally see it as inefficient and not worth continuing (even the supposed justification for climate change countermeasures is questionable in terms of effectiveness).
Due to its inefficiency, it is extremely uneconomical, requiring taxes and renewable energy surcharges to cover fuel procurement, taxes to cover the construction and operation of facilities, and renewable energy surcharges to be collected from users on the electricity sold (it may be worse than an octopus eating its own legs).
Furthermore, it is highly questionable whether other major objectives besides climate change, such as "utilizing unused domestic thinned timber" and "regional revitalization and improving energy self-sufficiency," can actually be achieved (imported fuels account for 63.2%).
I can't shake the question: can forest trees really regenerate that easily? (Even fast-growing cedar trees take 40-50 years to regenerate; are they truly a renewable energy source?)
The issue of illegal practices at the import source is also a major problem that cannot be overlooked.
Even if we generously postpone addressing the economic losses and environmental problems caused by misrepresentation and fraud, as these are unlikely to become major issues in the immediate future, several undeniable humanitarian problems have arisen. Personally, I would not want Japanese tax money or renewable energy surcharges to be used for imported biomass fuel immediately (it is unacceptable that taxes and renewable energy surcharges could potentially trigger humanitarian problems overseas).
Automated labor andSlave laborproblem
- Exploitation of land
- Incidents in which environmental activists and journalists who tried to stop illegal logging in national parks were eliminated by the mafia or colluding security forces.
etc.
For these reasons, I personally hope that biomass power generation will be gradually phased out (I feel this strongly from a humanitarian standpoint, and the renewable energy surcharge is a burden).
Since it only supplies about 5.9% of Japan's total electricity generation, shutting it down would have little impact on Japan's overall industry (it's an amount that can be easily compensated for by other power sources).
While there's nothing we can do about bio-power plants that have already been installed, I hope they'll be more cautious about installing new ones (it's understandable that operators can't immediately shut down existing power plants because they have employees to support).
Ideally, I'd like to see a gradual reduction in biomass power generation, so that biomass fuel can be supplied primarily domestically or imported from G7 countries. What do you think? (Importing large quantities of biomass fuel in the same way as now carries a frightening risk of triggering humanitarian problems; the probability of such problems occurring within Japan or among G7 countries is extremely low.)
So, what do you all think? I'd appreciate it if you could leave a comment.
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