As part of assessing the best energy sources for the future, we are looking at the pros and cons of these different energy sources.
This is our guide on the Pros & Cons Of Biomass & Biofuel Energy.
Summary – Pros & Cons Of Biomass & Biofuel Energy
- Renewable, unlike fossil fuels which are finite
- Can be carbon neutral
- Can be cost effective compared to coal and oil
- Biomass can be available in large quantities in some areas
- A range of biofuels can be produced
- Not ideal as a renewable energy source compared to solar, wind and other renewable sources
- Can be a huge waste of resources (water, land, fertilizer etc.)
- Can unnecessarily be the cause of deforestation and land clearing
- Can cause habitat loss, and negatively impact local species
- Can cause other environmental problems like land degradation
- Some biomass is highly polluting to the air
- Maintenance can sometimes be time and cost intensive
- Extraction of biomass may not be cost effective
- Can need a lot of land and storage space
- Can contribute to water scarcity and water depletion
- Can be inefficient
- Is still an energy source that is being developed in some places
Biomass and biofuel is certainly low cost if we are just using biomass waste. However, biomass and biofuels have many cons like efficiency, how much development still needs to be done, and the resources that are required to to produce biomass (water, land etc.). Growing trees and crops just for biofuel is perhaps worse from a sustainability and environmental perspective than fossil fuel usage. Overall, biofuels have potential (such as algal and new types of biofuel production), but at the moment, they are perhaps too resource intensive, inefficient and sometimes expensive to be a significant energy source. Solar, wind and water energy sources are better renewable energy options for the medium to long term – at least for electricity production.
- The main contributors of waste energy are municipal solid waste, manufacturing waste, and landfill gas.
- The future is moving towards algal, or algae-derived biomass because of it’s speed of growth and production rate without compromising food production.
- Produced at rates five to ten times faster than other types of land-based agriculture, such as corn and soy, and it can be fermented to produce biofuels such as ethanol, butanol, and methane, as well as biodiesel and hydrogen.
- As of 2015, a new bioenergy sewage treatment process aimed at developing countries is under trial; the Omni Processor is a self-sustaining process which uses sewerage solids as fuel in a process to convert waste water into drinking water, with surplus electrical energy being generated for export.
*Note – the above pros and cons are broad generalisations. Obviously there are different variables to each specific energy project that impact the final pros and cons (like new technology that reduces emissions for coal power plants just as one of many examples). Each energy project and situation (in different countries and cities) should be analysed individually. Having said that, some broad principles and patterns about the pros and cons of different energy sources tend to stay consistent too.
What Is Biomass & Biofuel Energy
Biomass is organic matter from plants and animals (microorganisms). Photosynthesis is the name of the process that stores the energy from sunlight in plants. Animals get this energy through eating the plants.
Waste such as crops, manure and garbage are all forms of biomass.
Biomass has a wide array of uses such as directly as heat or to generate electricity with a steam turbine.
Biomass can also be used to make methane gas, biodiesel and other biofuels.
Conversion of biomass to biofuel can be achieved by different methods can be categorized into: thermal, chemical, and biochemical methods.
The source of biomass, biofuels can be generally classified into two major categories. First-generation biofuels, sourced from plants such as sugarcane and corn starch, are ferrmented to produce bioethanol. The sugars present are turned into an alcohol fuel which can be used directly in a fuel cell to produce electricity or serve as an additive to gasoline (ethane). Second-generation biofuels utilize non-food-based biomass sources such as agriculture and municipal waste. This low-value industry waste is a favored alternative, although economical production of second-generation biofuel is not yet achieved due to technological limitations with chemical inertness and structural rigidity of lignocellulosic biomass
– energyinformative.org, and efficientgreenpower.com
There are five general categories of biomass: industrial waste and co-products, food waste, agricultural residues, energy crops, and virgin lumber
Biomass fuels provided about 5% of total primary energy use in the United States in 2017. Of that 5%, about 47% was from biofuels (mainly ethanol), 44% was from wood and wood-derived biomass, and 10% was from the biomass in municipal waste.
In lesser developed countries and regions, they have never had access to fossil fuels, and have been burning mainly wood, and other biomass for centuries.
Biomass & Biofuel Energy Pros
- Renewable – there will always be crops, manure and garbage. Renewal takes as long as those biomasses take to accumulate.
- Harnessing Energy From Biomass Is Cost Effective – Energy harnessed from biomass is inexpensive compared to coal and oil (where you have to drill for oil or create gas pipelines for gas). Typically they cost about 1/3 less than fossil fuels doing the same job. This means you can spend 1/3 less every year on heating your home and after 10 or 15 years that adds up to a considerable saving
- Abundant – Biomass is available in large quantities all over the world
- Biomass Can Be Carbon Neutral – plants absorb C02 from the atmosphere, and when they decay or are burnt for energy, C02 is released back into the atmosphere. So, the only C02 that is released, is what was absorbed in the first place.
- Can Be Used For A Range Of Biofuels – biomass can be processed to create biodiesel for vehicles, but it can also be used to farm methane gas and a range of other biofuels. Wood can be used to generate heat, while the steam produced by some forms of biomass (like from landfill) can also power turbines to create energy
Biomass & Biofuel Energy Cons
- Growing Trees Or Crops Just For Biomass Is A Big Problem – can contribute to deforestation and destroy wildlife and land/soil. Growing biofuel crops also takes land, water, and fertiliser, and produces carbon emissions (with the off site production of fertiliser itself)
- Some Biomass Is Highly Polluting – Biomass fuels such as ethanol are no less a pollutant than fossil fuels. Combustion of ethanol is incomplete and this produces the black carbon which is known to increase global warming. Also, if wood is not burned completely, it emits carbon monoxide and particulate matter, which are common air pollutants. There is also machinery that is used to extract and transport biomass that emits C02 and GHGs.
- There Is Maintenance Sometimes – crops and trees (for the wood) need to be re-grown and tended to.
- Extraction Of Biomass May Not Make It Cost Effective – some biomasses are not commercially viable when taking into consideration what it takes to extract them. This is true for the harvesting and storing of some biomasses.
- Can Need Large Physical Space For Storage & Growing – biomass storage can need large physical areas. Also, the growing of trees and crops takes space and soil/land.
- Requires Water – for irrigation to grow crops and trees.
- Has Inefficiencies – compared to fossil fuels, like petroleum and gasoline. Sometimes biofuels are combined
- Is Still Being Developed – many of the cons of biomass and biofuels are still being worked on and developed
- Not A Leader For Renewable Energy – compared to solar and water sources, biomass is inefficient and under-researched.