Is Biomass Renewable Disadvantages?

What is Biomass?

Biomass refers to organic matter that comes from plants and animals and contains stored energy from the sun. It is considered a renewable energy source because the energy it contains comes from the sun, and it can regrow over relatively short periods of time (https://www.eia.gov/energyexplained/biomass/).

Common forms of biomass used for energy include wood and wood waste, agricultural crops and waste material, food, lawn, and yard waste, animal manure, and human sewage. These can be directly burned for heat energy or converted to liquid biofuels like ethanol for transportation (https://www.eia.gov/energyexplained/biomass/). Biomass can also be converted to biogas through anaerobic digestion.

The chemical energy contained inside plants gets passed on to animals and people that eat them. Biomass stores this energy through the process of photosynthesis. When biomass is burned, it releases the solar energy it contains. Heat from the burning biomass can be used directly for heating or to generate electricity (https://www.nationalgeographic.org/encyclopedia/biomass-energy/).

Advantages of Biomass

Biomass energy has several notable advantages that make it an attractive renewable energy source. First, biomass is considered carbon neutral because the carbon dioxide released when biomass is burned is balanced by the carbon dioxide absorbed by plants during their lifetime (1). This makes biomass a more sustainable option compared to fossil fuels. Additionally, biomass is a renewable resource as plants and organic matter used for biomass production can regrow relatively quickly (2).

Another advantage of biomass is that it helps reduce waste. Many types of biomass come from waste materials such as municipal solid waste, agricultural waste, and landfill gas. Using these waste materials for energy generation reduces waste volumes while also offsetting fossil fuel usage (3).

Biomass also provides a local source of energy in many cases. Biomass feedstocks can be grown and harvested locally, then used to produce energy for local needs. This local production and usage improves energy security and saves on transportation costs (1).

Overall, key advantages of biomass that make it an attractive renewable energy option include its carbon neutrality and sustainability, waste reduction capabilities, and potential to provide local renewable energy.

Sources:

(1) https://www.edp.com/en/edp-yes/energy-from-biomass-advantages-and-disadvantages-alternative-source

(2) https://www.energysage.com/about-clean-energy/biomass/pros-and-cons-biomass/

(3) https://www.syntechbioenergy.com/blog/biomass-advantages-disadvantages

Disadvantages of Biomass

While biomass has some advantages as an energy source, it also comes with some notable drawbacks. One major disadvantage of biomass is its high cost compared to fossil fuels. The production and processing of biomass is an expensive process due to the large amount of labor, water, fertilizers and energy required ^[1]. The expense of growing, harvesting and transporting bulky biomass material impacts the overall cost.

Another disadvantage of biomass is its low energy density compared to fossil fuels like oil and coal. Biomass has around one-third the energy density of fossil fuels, which means more raw material input is needed to produce the same amount of energy output ^[2]. This also adds to the overall expense. The transportation and storage costs are higher due to the large volumes needed.

Biomass facilities can also lead to increased air pollution in some cases. The burning of biomass releases carbon dioxide, nitrogen oxides, sulfur dioxide and particulate matter into the atmosphere. This contributes to smog, acid rain and respiratory problems if not properly controlled and regulated ^[3]. While less than coal, biomass still needs effective emissions controls.

Land Use Conflicts

One of the main disadvantages of biomass energy is that it can compete with food production for land use. As demand for biomass energy increases, more land may be converted from growing food to growing energy crops. This could raise food prices and impact food security.

According to a 2020 study published in Renewable and Sustainable Energy Reviews, “Land use conflicts between biomass and power production” (source), biomass energy production often conflicts with other land uses like food production and nature conservation. The study notes that energy crop cultivation competes for arable land that could otherwise be used to grow food crops.

There are also concerns that increased demand for biomass could lead to deforestation in some regions. According to the Environmental Justice Organisations, Liabilities and Trade Project (source), industrial tree plantations grown for biomass energy are a major driver of deforestation and can displace rural communities that depend on forests for their livelihood.

More sustainable practices and careful land use planning is needed to minimize conflicts between biomass energy production, food production, and conservation goals.

Air Pollution

Burning biomass releases several types of air pollutants like particulate matter, nitrogen oxides and carbon monoxide. Particulate matter or PM is made up of small particles that can get into the lungs and cause respiratory problems. Sources cite that PM emissions from biomass combustion are in the range of 100 times higher than natural gas (EIA, Tomlin et al.). Burning biomass also emits nitrogen oxides which contribute to smog, acid rain, and respiratory problems. Nitrogen oxide emissions are 10-100 times higher from biomass compared to natural gas (PFPI). Carbon monoxide is another major pollutant from biomass burning which reduces the amount of oxygen reaching body tissues. Overall, experts agree biomass combustion emits high levels of PM, nitrogen oxides and carbon monoxide compared to fossil fuels. Proper emissions controls can help mitigate air pollution but biomass inherently produces higher emissions than cleaner energy sources.

High Cost

Biomass plants have high capital costs compared to conventional fossil fuel power plants. According to a report from the U.S. Department of Energy, biomass heating plants have installed costs that typically average between $500 to $1500 per kW-thermal of installed heating capacity [1]. This is significantly more expensive than building a natural gas power plant.

Fuel costs for biomass can also be high since biomass feedstocks need to be constantly harvested, processed, and transported to the plant. The fuel itself, whether wood chips, agricultural waste, or biofuels, costs more per BTU than coal or natural gas. According to EnergySage, the cost of biomass ranges from $4 to $8 per MMBTU compared to just $2 to $3 for natural gas [2].

Transportation logistics also add substantial costs for getting bulk biomass material like wood chips to the plant. Trucking and rail costs can be high for constantly moving large volumes of biomass feedstock from the harvesting locations to the power plant.

Low Energy Density

One of the main disadvantages of biomass as an energy source is its low energy density compared to fossil fuels. Biomass has a lower heating value per unit weight than coal, oil, or natural gas. This means that compared to fossil fuels, much larger quantities of raw biomass material are needed to produce the same amount of energy ¹.

For example, on a per unit energy basis, biomass requires about 4 times the volume of coal to produce the same energy output. The bulkiness and weight of biomass can make storage, handling, and transportation more expensive and challenging compared to more energy dense fossil fuels ². Large-scale biomass energy plants require substantial amounts of feedstock to operate, which requires harvesting and transporting massive quantities of wood, plant matter, or waste materials.

The low energy density of biomass is an inherent limitation of the resource. While technological innovations and efficiencies can help improve the process, a large volume of raw biomass is needed to produce meaningful energy output. This presents logistical challenges and higher costs compared to using fossil fuel alternatives.

Transportation Challenges

One of the main disadvantages of biomass is the challenge in transporting bulky raw materials. According to the report “Optimizing Biomass Transport: Challenges and Solutions” from Forest Steel^[1], biomass has a low energy density compared to fossil fuels. This means transporting a useful amount of biomass requires a large volume and frequent trips. Trucks can only carry about 25 tons of biomass per load, whereas they may haul 30,000 gallons of fuel oil.

The bulkiness of biomass feedstocks increases transportation costs due to more frequent trips and specialized equipment needs. The moisture content also makes biomass heavier to transport. Solutions proposed involve developing densified biomass products like wood pellets to increase energy density. However, processing raw biomass into dense products requires additional energy and cost. Overall, the logistical challenges of transporting bulky biomass can make it less economical than fossil fuel alternatives.

Sustainability Concerns

While biomass is considered a renewable energy source, there are some sustainability concerns when it comes to large-scale biomass production [1]. One major issue is unsustainable farming practices. To produce large quantities of biomass for energy production, massive areas of land are needed. This can lead to overuse and depletion of soils as well as increased use of chemical fertilizers [2]. Continuous planting and harvesting of biomass crops degrades soil quality over time.

Another sustainability issue is carbon debt. While burning biomass is considered carbon neutral, this doesn’t account for the timeframe. Cutting down forests or grasslands to produce biomass releases large amounts of carbon dioxide upfront. It can take decades or even centuries for the regrowth of biomass crops to fully offset these initial carbon emissions [3]. This creates a carbon debt that counters the intended climate benefits of biomass energy.

Alternatives

While biomass energy has some advantages, it also has concerning disadvantages. Many argue there are better renewable energy alternatives.

Solar energy is considered one of the most promising renewable energy sources. Solar panels convert sunlight directly into electricity without any emissions. Solar energy could potentially meet worldwide energy demand with minimal environmental impact (https://www.nrdc.org/stories/renewable-energy-clean-facts).

Wind power is another rapidly growing renewable energy source. Wind turbines convert the kinetic energy of wind into mechanical power or electricity. Wind power produces no emissions during operation and has a small land footprint per kWh compared to biomass (Alternative (Biomass, Ethanol) – Energy – Supply, Demand …).

Geothermal energy utilizes heat from the earth’s interior for heating or electricity production. Geothermal power plants have low emissions and provide constant base-load power not subject to weather variations. Enhanced geothermal systems could provide large amounts of renewable power with minimal land use (Cleaner production alternatives: Biomass utilisation options).

Overall, other renewables like solar, wind, and geothermal energy may provide cleaner and more sustainable alternatives to biomass power.