Advantages and Disadvantages of Biomass Energy

What is Biomass Energy?

In 2018, the United Nations estimated that the world will pass 1.5 degrees Celsius of warming by 2040 if we continue at the current emissions rate. Therefore, staying below 2 degrees Celsius of warming most likely requires not just scaling back our carbon emissions, but also creating “negative emissions”. There are two ways in which to do this: the first is technologies that would suck carbon out of the air and the second is new approaches to forestry and agriculture that would do the same. The biomass energy sector hopes to be able to do both. Since the earliest days of mankind, early humans have been using the energy from living things for cooking or keeping warm. Currently, bioenergy is the largest renewable energy resource in the world. It is also the most heavily subsidised renewable energy resource. National Geographic defines biomass energy as power generated or produced by living, recently living, or once-living organisms, primarily plants. Biomass can also refer to any source of heat energy produced by non-fossil biological materials. Biomass materials used for energy include corn and soy products, which can be burned to create heat or converted into energy. Others can range from firewood to ethanol, to sugarcane or methane captured from landfills.  

The use of fire is the first form of biomass energy used by man. Humanity initially utilised biomass for cooking and heating, but the 19th century sprouted an interest in more modern uses of biomass materials. Biomass can have two applicable uses: burning organic materials directly to create heat and converting biomass into a liquid biofuel that can then be burned for energy.  

Ethanol was the first big leap in employing carbon for energy. Derived from grains, ethanol was used for cooking and lighting from the 1100s onwards. People began using ethanol to create power. The feedstock from grains was plentiful, which meant that it was a very popular renewable source of energy. Ethanol and turpentine from pine trees were the two substances to power the first engine in 1826 and continued to be a popular fuel until the 1890s. Fish and vegetable oils were also known to be popular sources of energy to generate heat and light. The ancient Egyptians and Sumerians are believed to have burnt animal and vegetable oils. Turpentine, or pine sap, was another valuable renewable resource from the 1700s to the 1960s. Turpentine was initially used as an alternative energy source for lamp oil. 

The arrival of oil derailed bioenergy’s progress and popularity in the markets. The commercialisation of the coal and crude oil industry brought fossil fuels to the forefront of the energy market, eclipsing the less efficient and practical biofuels in the process. However, a geopolitical conflict in the 1970s brought about a fuel crisis; one that is not dissimilar to the very recent fuel crisis felt during the Russian invasion of Ukraine. During the first fuel crisis, governments and the academic world began looking into rebirthing and expanding more renewable energy sources. The boom in green energy also restarted the interest in biomass.  

Over the past 19 years, biomass, geothermal and solar thermal energy have doubled their share in the global heat production market. Now, biomass accounts for 98 per cent of renewable energy generation. The European Union spent 6 and a half billion euros on subsidies for biomass power plants in 2017. 655 terawatt hours of electricity were generated from biomass globally in 2019. 68% of biopower generated was from solid biomass sources, and 17% was from municipal and industrial waste. Asia dominated the biomass market with 39% of biopower generated globally, followed by Europe with 35%. However, Europe leads the world in producing heat in biomass power plants. The continent dominates with a share of 88% globally.  

Disadvantages 

Despite the potential advantages of biomass energy to produce “negative emissions”, the European Academies Science Advisory Council found that all existing negative-emissions technologies only have very ‘limited realistic potential’ to slow the increase of global carbon emissions.  In reality, the burning of forest biomass releases swaths of climate-warming pollution back into the atmosphere and destroys crucial carbon-capturing ecosystems. The governmental subsidies, as well as, the categorisation of biomass as “carbon neutral” and a form of renewable energy, are setting us back decades in the fight against climate change. While technological advances are sure to come, which will bring costs down and make more efficient machines, the world does not have the time for that progress. Meanwhile, companies are scaling up production. An increase in the production of biomass has the potential to markedly offset the use of fossil fuels but also maintains scores of issues. The energy can threaten conservation areas, pollute water resources, and decrease food security. The global potential for energy production is large in absolute terms, but the amount of not nearly enough to replace more than a few per cent of current fossil fuel usage. Scaling up production beyond this level would probably reduce food security and exacerbate the effects of climate change. Despite having the potential to decrease net emissions of carbon, if investments and strategies are successfully monitored biomass has in reality increased net emissions of carbon in the atmosphere. Increased deforestation of energy-demanding manufacturing technologies can contribute to greenhouse gas emissions being added, not reduced. Additionally, the production of biomass energy always requires the use of fossil fuel energy. These emissions come in the form of farming, transportation, and manufacturing.  

Some authors have claimed that biomass energy does not reduce carbon dioxide emissions at all, and say it consistently instead increases them. Cape Cod Times reported that wood-burning power emits 50% more carbon dioxide per unit of energy than the traditional fossil fuel of coal. Supported by scholarly research and climate scientists, the Times author posits that biomass is a “greenwash” of the timber and energy industries attempting to create a profit on the lucrative public interest in green energy. Scholars oppose the construction of dirty, carbon-belching, forest-degrading biomass incinerators. Wood-burning power is comparatively inept; production has only about 23% efficiency and the other 77% of the trees go up in smoke without producing any useful energy. Substantial amounts of forest must be cut down to provide a small amount of power. A large risk of the expansion of biomass energy is the transformation of vibrant, natural areas to managed monocultures and contaminating waterways with agricultural pollutants. If the wood used to create biomass is forest waste, damaged trees, and other unproductive flora of nature, a portion of this disadvantage would be eliminated. (This is termed “waste biomass”, which will be discussed later.) Problematically, much of the time this is not the case. A US research paper on biomass asserts that biomass resources include wood wastes, residues from the production of paper and forest products, agricultural residues, long-rotation woody plantings, thinnings, logging residues and herbaceous crops developed specifically for energy production. This industry needs to hold itself to this fuel standard for biomass production.  

For example, a biomass energy power plant in the UK named Drax, prides itself on being “the biggest decarbonisation project in Europe” as it delivers a decarbonised economy and healthy forests. However, the New Yorker reported that Drax emitted more than 15 million tons of carbon dioxide into the atmosphere in 2019 alone. That is the greenhouse gas emissions equivalent of three million cars on the road in one year. 60 thousand acres of trees are burned each year to supply the growing pellet market, as reported by the Dogwood Alliance. These trees would have otherwise stayed intact and continued to sequester carbon naturally. Additionally, global demand for wood pellets is expected to double within the next 5 years, causing more deforestation and removing even more carbon-sequestering trees. The biomass power plants that cut down the trees are not required by law or in any policy or legislation to ensure the trees grow back or to replant trees. Even if there were strict laws to ensure the removed trees get replanted, a new tree needs between 40 to 100 years to pay back the carbon debt caused by the logging and burning of the old tree. The United Nations specifies that bioenergy should only be used in limited applications due to the potential negative environmental impacts of large-scale forest and bioenergy plantations. They say the main results are deforestation and land-use change.  

Biomass also has a major inefficiency problem. Currently, the primary source of biomass fuel for liquid transportation is ethanol from corn or sugarcane, or biodiesel from rapeseed, soy, or palm oil. Ethanol is the most unpromising of biomass fuels. The entire global harvest of 700 million tons of corn converted into ethanol would yield enough transportation fuel for only 6% of the global gas and energy demand. Furthermore, a substantial amount of fossil fuel energy would be required to produce ethanol as well. By combining these factors, the entire global harvest of corn to ethanol would offset under 1% of carbon emissions from fossil fuels. Sugarcane to ethanol is somewhat more optimistic, due to the pathway having an energy balance ratio of 8 to 10. However, there are not enough sugarcane crops for their corresponding biofuels to be scalable for the entire global energy system. If the global harvest of corn, sugarcane, soy and palm oil were converted to fuels using the current technologies, only 3% of the global energy market would be served. There is also a lack of reliable and updated data on bioenergy power in both global and local systems. Due to the highly informal and localised nature of the feedstock and technology used in the bioenergy production industry, the data is inhibited by a myriad of difficulties. Data is challenging to gather, analyse, and report in with accurate and updated information on overall bioenergy developments. Thus, reports may not be as precise and funding might be withheld due to a lack of seeming progress or effectiveness.  

Advantages 

Biomass is not all bad. It has many promising uses and possibilities to help aid the fight against climate change. Simply put, biomass energy allows us to create energy without the use of fossil fuels thanks to natural, ecological resources. With biomass, we have the opportunity to recover waste and reuse it to our advantage. We can turn biomass into electricity, fuel, plastic, and solid carbon. It can also be engineered to sequester more carbon dioxide, injected underground, or sunk to the bottom of the ocean. In the future, biomass energy has the potential to provide a sustainable and cost-effective supply of energy, while also aiding countries in meeting their greenhouse gas reduction targets. Biomass energy is capable of heightening energy security in regions without abundant fossil fuel reserves and increasing supplies of liquid transportation fuels. Some scholars say that energy is also promising in decreasing net emissions of carbon into the atmosphere per unit of energy delivered. Through the appropriate technologies, the burning of compacted biomass energy pellets for heat fuel might be the most efficient commercial use of biomass energy. Nonetheless, as we mentioned above, the industry is highly problematic and unregulated. With the right legislation and practices, burning wood pellets can be beneficial instead of contradictory to climate efforts. Small-scale biomass energy can be highly advantageous. The incidental harvesting of trees on a small scale can theoretically keep up with forest regrowth. The IPCC was previously known to be very supportive of biomass as a minor part of energy production; little did they know that vast amounts of forests would be cut down and shipped across the country to create this energy.  

To ensure a prosperous future for biomass, we need to keep the ecosystem awash and in equilibrium: carbon goes in and carbon goes out. Trees suck the carbon out of the atmosphere as they grow, and release it back out when they decay. When we deforest too much, we release carbon stocks and put them into the atmosphere and much higher rates, essentially disrupting nature’s harmonious equilibrium. If the industry works towards maintaining nature’s course, biomass can ultimately be beneficial for the fight against climate change. There is a trade-off between the natural world and agriculture. If you grow forests to convert them into biomass, this land is in direct competition with where we grow food and cultivate our crops. Since there is a limit on forests, oceans, land, and nutrients in living things, waste biomass is a way to sidestep this issue. Waste biomass at its core is keeping garbage out of the atmosphere by using it in a meaningful and productive way. It also aids the planet by releasing pressure on landfills by reducing the garbage put into them. Investors and governments are turning their focus on this new means of sequestering carbon or creating fuel.  

As mentioned briefly above when discussing forests, forestry waste including bark, twigs, dead trees, and any other futile and superfluous matter can be used for waste biomass purposes. Two other forms of waste biomass include agricultural waste and municipal solid waste. Agriculture waste can include almond pits, walnut husks, and dead straw while municipal solid waste is our trash; this is anything from the food we throw away to the plastics we throw away. By burning all of this solid waste, 2.5 to 5.5 billion tons of carbon dioxide can be removed from the atmosphere by using this waste. The amount of garbage dumped in landfills can also be reduced by 60 to 90 per cent. Biomass can also be used as a carbon sequestration method. When not used for biomass, forestry waste is sent to the landfill to rot down or sent to incineration to be burned to ash. In both of these cases, 100 per cent of the carbon is released into the atmosphere. Instead, this waste can be made into biochar. The wood is not turned into ash but is converted into organic material and crystalline porous structure which cannot biodegrade. This results in the carbon being captured and stored for hundreds of years. Additionally, farmers and gardeners can use this biochar as horticultural charcoal to improve soil fertility and plant health.  

There are multiple ways to create biogas. Gasification is another innovative method to transform solid biomass into useable combustible gas. Through a thermochemical process, raw materials are transformed into biogas, which are then used as fuel. Four broad feedstock categories can be used to create biogas: animal manure, crop residues, food and green waste, and wastewater sludge. While this technology is in its early stages, Japan and Australia are building lignite gasification plants and terminals for unloading this type of fuel. Biomethane, also known as renewable natural gas, is produced by upgrading biogas or through the gasification of solid biomass followed by methanation. The woody feedstock is fermented, not just burned, in these biomass power plants. This process called methanization or methanation can create biogas for fuel for the operation of cars and trucks. This method is rising in usage – as of the end of 2020, France had 214 biogas plants.