Biomass" refers to energy resources produced from plants, animals, and other living organisms, excluding fossil fuels such as petroleum. Bioethanol made from corn, for example, is a well-known fuel used in automobiles.

Biomass power generation is a method of power generation that uses biomass fuels to extract energy and generate electricity by directly burning biomass fuels or by burning methane gas, etc. generated by fermentation.

Biomass energy is attracting attention as a form of renewable energy because it can be generated sustainably through the cyclical regeneration of plants and other raw materials.

Biomass-derived fuels include wood fuel, biodiesel, bioethanol, and biogas.
Of these, wood fuel and biogas are used for biomass power generation.
Wood fuel refers to the use of woody biomass such as thinned wood or waste wood as fuel. Biogas is the gas produced by fermentation of waste biomass such as food waste and livestock manure.

How does biomass power generation work?
There are three main types of biomass power generation methods: direct combustion, pyrolysis gasification, and biochemical gasification.

The direct combustion method generates electricity by directly burning biomass.

In the direct combustion method, biomass such as wood, combustible waste, and waste oil is processed to be easily combustible and burned in a boiler. The heat energy is used to generate steam, which is then used in a steam turbine to generate electricity.
This method is used for large facilities due to its low combustion temperature and power generation efficiency.

In the pyrolysis gasification method, biomass is gasified by heat treatment at high temperatures to generate electricity using a gas turbine or gas engine.
This method has higher combustion temperatures and can achieve a certain level of power generation efficiency with smaller facilities than direct combustion methods.

In the biochemical gasification method, biomass is gasified through fermentation, etc., and electricity is generated by a gas turbine or gas engine. Specifically, livestock manure, raw garbage, sewage, and sludge are fermented to generate methane gas.
This method is used for waste biomass that is difficult to burn directly due to its high water content, and the high calorific value of the gas generated makes power generation highly efficient.

Biomass power generation is attracting attention as a form of renewable energy, but what are the advantages and disadvantages of biomass power generation?

Here we introduce the specific merits and demerits of biomass power generation.

First, let's look at the advantages of biomass power generation.

Stable Power Generation
Biomass power generation is more stable than other renewable energies because energy is not dependent on the natural environment, as is the case with solar and wind power generation.

Carbon Neutral
Biomass has great merit as a contribution to a recycling-oriented society and as a countermeasure against global warming.
For example, in the case of woody biomass, the trees used as raw materials absorb carbon dioxide from the atmosphere. When woody biomass is generated from trees and burned, carbon dioxide is produced, but this does not affect the increase in atmospheric carbon dioxide concentration if carbon dioxide absorbed from the atmosphere is considered to have been returned to the atmosphere.

From this perspective, biomass energy can be considered to be carbon neutral, meaning that CO2 emissions are virtually zero.

For more information on carbon neutrality, please refer to " What is Carbon Neutral? Explanation of its purpose, initiatives, and company case studies! for more information.

Resource recycling
Wood chips used as fuel for biomass power generation are made from unused wood generated from thinning of forests. In the case of waste biomass, waste materials that would otherwise be discarded are used as raw materials. In both cases, the use of discarded materials as raw materials contributes to the reduction of environmental impact from the perspective of resource recycling.

This is followed by a discussion of the disadvantages of biomass power generation.

Feedstock Procurement Costs
When biomass fuels are used, it is necessary to collect, transport, and manage the feedstock.

In the case of wood fuel, the collection and transportation of thinned wood and waste wood is required. In the case of waste biomass, the collection and transportation of raw materials dispersed on a small scale, such as food waste and livestock manure, is required, and these costs tend to be high.

This is a disadvantage, given that power generation using natural energy, such as solar power and wind power, does not involve the above costs.

Low Power Generation Efficiency
The efficiency of biomass power generation is low; for example, the efficiency of woody biomass power generation is about 20% to 25%.
The efficiency of other power generation methods is about 55% for thermal power, 80% for hydroelectric power, 20-40% for wind power, and 20% for solar power. However, biomass power generation, which requires the procurement of fuel, must have a higher efficiency than solar power generation, which does not require the procurement of fuel, or else it would be less economical.

Waste Liquid Treatment in Waste Biomass (Biogas)
When waste biomass is used as fuel, the effluent (digested liquid) generated after power generation from biomass power plants has a high environmental impact and can cause pollution if not properly treated. The cost of waste liquid treatment is also a factor that increases the cost of biomass power generation.

Biomass power generation has not only advantages but also disadvantages such as these.

The FIT (Feed-in Tariff) scheme, introduced to promote the spread of renewable energy, has also been applied to biomass power generation. According to the Ministry of Economy, Trade and Industry, the cumulative installed capacity of biomass power generation before the introduction of the feed-in tariff scheme (end of June 2012) was approximately 2.3 million kW, while the cumulative installed capacity since the introduction of the scheme is 2.651 million kW, more than double the capacity of biomass power generation before the FIT scheme.

On the other hand, biomass power generation is also subject to feed-in tariffs under the FIT system, but in Japan, which relies on imports of biomass fuel, the economic benefits tend to be smaller than those of other renewable energies, especially since the cost of power generation is higher than for other renewable energies. In addition, the declining cost of solar and wind power generation over the past few years has become a headwind for biomass power generation.

The key to solving these issues is a model of local production for local consumption of energy that takes advantage of local resources.

Güssing, Austria, known for its local production and local consumption of renewable energy, mainly biomass, developed a power generation facility using woody biomass in 1996, and has since been nurturing locally produced renewable energy for local consumption as a regional industry for more than 20 years. In the process, the company has been working to reduce fuel costs for biomass power generation by generating woody biomass from wood chips from forests, a local resource, and by purchasing wood chips and offcuts from local business activities.

Through these efforts, the area has become self-sufficient in energy and has succeeded in attracting more than 50 companies to the area, attracted by the stable procurement of renewable energy. This regional revitalization through local production and local consumption of renewable energy is known as the "Güssing Model.