• I made my own food compost bin for $12 - my how-to-do-it story is here
Hello from the United States!
My name is Alyssa Noble. I am majoring in Sustainability with a related discipline in Urban Planning as a senior at Arizona State University. I attend online since I live nearly 1,700 miles (2,736 km) away in Louisville, Kentucky. This summer, I have been interning with Michael Mobbs at Sustainable House all the way in Sydney, Australia. It has been enlightening to see the similarities and differences in our countries and their efforts to reduce climate impact.
• This map of the United States shows the location of my hometown, Louisville, Kentucky
Here in America, we get most of our energy from crude oil (35%) and natural gas (34%) [12]. Over in Australia, most of their energy comes from coal (40%) and crude oil (34%).
Fossil fuels, or fuels made from Earth materials that takes millions of years to make, have been the leading energy sources for us. Resources will be depleted for future generations if we keep business as usual. Renewable energy, or energy that comes from materials that are quickly replenished, has been on the rise and is expected to drastically increase over the next few decades.
A category of ‘renewable energy’ that is considered the next big thing worldwide is bioenergy.
According to the Australian Government, “Bioenergy is a form of renewable energy that uses organic renewable materials (known as biomass) to produce heat, electricity, biogas and liquid fuels.”
But the data tells me - it’s not ‘renewable’ and is not sustainable.
This blog is long because there’s lots of data. The issue of burning food, timber and other things is important for our cultures, and Earth, and I want to share the data and research with you to support what I’ve written.
The biomass used to make the different kinds of bioenergy can be anything ranging from yard scraps, food waste, crop residues, animal manure, sewage, wastewater, trees, or even landfill gas.
Bioenergy accounts for a big portion of renewable energy. Just in 2017, bioenergy made up 50% of the world’s consumption of renewable energy . In 2020, biomass contributed 39% of renewable energy in the US with nearly half of that coming from wood.
• A pie chart made by the U.S Energy Information Administration shows our energy consumption. As you can see, biomass is a major source of renewable energy for us
Energy from Burning Biomass
At the beginning of this year, news spread globally that over 500 scientists signed a letter to world leaders with a clear message: Stop burning trees for energy. This message comes at a time where burning trees has been falsely marketed as carbon neutral.
The scientists state that for each kilowatt hour (kWh) unit of energy produced by burning wood and trees, 2 to 3 times more carbon, the leading greenhouse gas, is released into the atmosphere than when burning fossil fuels. This is because it takes more wood to produce the same amount of energy as a significantly smaller amount of coal or natural gas would.
Cutting down healthy trees for energy goes against the global progress made on reducing carbon, which traps heat in our atmosphere and keeps it warmer than it would normally be.
Established old-growth forests absorb and hold carbon better than young, replanted forests. This explains why keeping natural forests the way they are is crucial for our climate goals to be reached. Scientists believe that leaving forests alone could be the most effective climate solution that is available to us.
Trees also provide homes for the diverse mammals, birds, reptiles, and insects. The importance of biodiversity is understated, and trees are needed for the survival of many other species besides humans.
“Regrowth takes time the world does not have to solve climate change .” - Unknown
• Lorne State Forest, NSW, Australia. Intensive logging by Forestry Corporation NSW, 2018, with relaxed regulations
In Australia and Europe, the transition to burning biomass has raised the rate of logging. Since 2015, one study found that there has been a 70% increase in cutting trees across Europe.
When forests are logged, nearly all the trees in an area are cut down and broken down into smaller pieces, known as woodchips, to burn.
Biomass was not meant to be based only on trees. Remains from crops and waste from industrial paper mills would originally be burned, but in many cases, there was just not enough materials to keep up. This leaves logging to act as a safety net for some biomass energy plants.
As a result, regulations and policies that control the land used for logging have been relaxed in many places. For example, logging on private and state forests in New South Wales, Australia has been encouraged by lowering the number of trees that need to be kept by half. It is also hard to keep an eye out on private lands to ensure forest laws are being followed.
In Warkworth, NSW, Australia’s first 100% wood-based energy plant is in the making. Hunter Energy, soon to be known as Verdant Earth Technologies, purchased the former coal-powered Redbank power plant in hopes of converting it to biomass.
The biomass to be burned can be sawmill and wood processing remnants, forest residues from harvesting, and end-of-life and industrial wood waste streams. The plant plans on burning 850,000 Tonnes yearly to produce 151MW of energy, scoring within the top 10 of largest biomass power plants in the world if it opens.
• An aerial view of the Redbank Power Plant, which used to operate on coal and is in the process of being converted to biomass
Burning Biomass in Kentucky
In comparison, the state of Kentucky has two wood-burning energy plants. Neither are close to Louisville, and since Kentucky gets 0.5% of its energy from biomass, I most likely will never use biomass energy at my home.
The first plant, Cox Waste to Energy in Campbellsville, has a capacity of 3.3MW and is in the center of the state. It opened in 1995 with the purpose to save waste disposal costs for the owner, Charles Cox. He also owns a wood manufacturer business that produces an average of 100 tons of wood waste per day. His plant can burn up to 300 tons per day. You can learn more about how they operate here.
The second plant, Kentucky Mill, has a capacity of 49MW and is located at the Hawesville Mill, an industrial paper and pulp manufacturer that is 90 minutes West of my home. Since the paper plant is massive, this biomass burning plant serves the same purpose as Cox Waste to Energy. It provides an on-site wood disposal method for a business that generates a lot of wood waste.
• The Hawesville Mill, located off the Ohio River and operated by Domtar LLC, a major paper manufacturer
Energy from Digesting Waste
Another popular way to get bioenergy is biodigestion, otherwise called anaerobic digestion.
The Student Energy organization defines anaerobic digestion as a process that occurs when organic matter is broken down by bacteria without oxygen to create biogas.
Anaerobic digestion can convert different waste materials into energy, yet food waste, animal manure, and wastewater sludge are most common.
Biogas is composed mostly of methane, another harmful greenhouse gas, and carbon. The carbon is filtered out and the remaining methane is burned as fuel or converted to electricity. Energy industries suggests that biogas may become a replacement for natural gas.
To reduce the amount of waste entering landfills and help meet renewable energy goals, anaerobic digestion is being posed as a solution for countries around the world. Professor Bernadette McCabe from the University of Southern Queensland, Australia, asserts, “Australia is transitioning toward clean energy technology, giving biogas a massive opportunity to help meet renewable energy targets and decarbonization efforts, as well as providing a holistic solution to a range of waste management issues.”
Motivation for Australia to use anaerobic digestion comes from industry and some politicians who say the technology can support the country’s commitment to the Paris Agreement to decrease emission levels to 26-28% below the 2005 level by 2030. There’s the formation of biogas lobby groups to connect members of the industry, government, and researchers.
The same motivations apply to other countries, especially those in Europe where the biogas industry is booming.
As of December 2016, there were 242 digesters functioning in Australia, where 129 of them were landfill biogas collectors.
• The number of digesters and estimated capacity in Australia in December 2016. I can imagine that number has risen in the last 5 years
Biodigestion in Kentucky
Given the ~300 million people population difference between the United States and Australia, the US is behind Australia when it comes to anaerobic digesters per capita. In April 2021, there were 273 livestock anaerobic digesters in the US. Most of the digesters are located on dairy farms in Wisconsin, California, and New York.
In my home state of Kentucky, there is only one livestock anaerobic biodigester. Coincidentally, it is in Campbellsville, which is where one of the two biomass plants in the state are.
This digester works much differently to, and is smaller than ,Australia’s first biodigester, EarthPower, which I’ve analysed, here.
First, it is located on a farm, called Mac Farms, and was paid for by the farmer, John McLean, rather than a big company. Second, his digesters use chicken manure and waste from bourbon distilleries, dog food production, horse feed production, and ham processing plants instead of food wastes.
McLean worked on his anaerobic digesters through years of trial and error, and after about 4 years, his digesters were finally profitable.
He invested in anaerobic digestion to save money on fertilizer for his crops and energy for his barns, especially during the cold winters, and to be more environmentally friendly. You can read McLean’s interview with the US EPA and get to know more about his journey and struggles with anaerobic digestion here.
• A map of the US shows all the livestock anaerobic digesters. The size of the circles indicates the energy capacity
Corn Powers Vehicles
Ethanol is a fuel made from biomass that is usually mixed with gasoline to power vehicles and machines. The most common ingredients used are corn, barley, sugar cane, and sugar beets through fermentation of the sugar, which changes the chemical structure, to create a clear alcohol known as bioethanol.
Across the US, it is government mandated that petrol gas companies have 10% ethanol mixed in to reduce the carbon emissions from burning fuel to get us along our commutes. The US is the world’s top producer of ethanol due to our plentiful supply of corn. The biofuel has a good reputation because it means that we are technically using less petroleum gas, plus it is plant based.
Yet around 40% of all corn production is going towards the energy industry to make ethanol and lobbyists are pressuring the Biden Administration to require a higher percentage of ethanol in gasoline. What impacts might this have?
There are currently around 166 million hectares of farmlands in the US, where 37 million hectares of that is for growing corn. 15 million hectares of those corn fields go towards making ethanol. This means that 8.8% of the total farmlands are reserved for making ethanol just to supply 10% of our fuel.
The ethanol industry wants to double the amount of ethanol mixed in gas to 20%. With that high demand, the total farmlands used for ethanol production would jump to 17.6%.
That is almost one fifth of our farmlands going towards something that nobody can eat.
![• A graph showing the percent of ethanol in our gasoline in relation to the percent of farmland that would be taken up for production [9]](https://images.squarespace-cdn.com/content/v1/55d039b5e4b061baebe46d36/1626924310183-YVKMIU6358GHO8SRVJD5/Screen+Shot+2021-07-22+at+1.23.50+pm.png)
• A graph showing the percent of ethanol in our gasoline in relation to the percent of farmland that would be taken up for production [9]
All of this is a big change compared to 20 years ago. Back in 2000, over 90% of corn production went to feeding people and animals. Corn was only $2 USD per bushel (35.2 liters of dry goods). As it became popular in the energy sector, the price of corn has more than doubled and is currently costing an around $4-7 per bushel. This is wonderful for farmers but encourages more of our sacred natural habitats to be converted into monocultured farmlands.
Since 2010, croplands have been expanding an average of 404,686 hectares every year.
The rising cost of corn also has a domino effect on the food industry. Cows, pigs, chickens, and other farm animals rely on corn for a source of food. As corn gets more expensive, so will meat, eggs, dairy, and other foods that include those products.
Professor David Pimentel, who was an active agricultural researcher, calculated the energy inputs and concluded that producing 1 liter of ethanol takes 6,600 kcal. 1 liter of ethanol, however, only contains 5,130 kcal. If there is more energy going into the production than the actual energy that the product contains, that indicates that producing ethanol is an energy-negative process. Ethanol takes 29% more energy than it can provide.
Water
Water usage is also something to keep in mind.
Water is a precious resource where some places don’t have enough to supply their populations. The agriculture industry is the main water consumer around the world, using nearly 80% of our water supply. Crops have a water footprint that is 72x more than crude oil and 240x more than solar energy. If the demand for corn grows higher, more water will be used, which may deplete some water sources and further progress agricultural runoff into water systems.
• The water usage between crude oil, solar, and biomass (crops). The crude oil and solar water usage are so small in comparison to biomass that you can’t see their bars
Simply stated, producing ethanol takes up too much land, raises the price of food, uses too much water, and is an inefficient energy source. The good reputation comes with a high price of misguidance to the public. Although the industry supplies thousands of jobs in the US, those jobs could go elsewhere for a better purpose.
Food is important for our survival, and as much as we waste, we should still be using nearly all the croplands to for food, not energy.
Here you can watch an informative, grasping-my-mind video about the unspoken aspects of ethanol and biofuels; buckle up.
Me, My Compost, You and Earth
When it comes to food, we waste nearly 30% of our global supply.
The United States alone produces around 40 million tons (36 million tonnes) of food waste each year that ends up in the landfill, which is worth an estimated $161 billion.
Australia also throws away around 7.3 million tonnes of food annually, totaling up to $20 billion.
• This shows the key facts about what kind of food we are wasting
• If food waste were a country, it would be 3rd place as top greenhouse gas emitter, just behind China and the U.S. Courtesy of the Food and Agriculture Organization of the United Nations
Basically, we are all throwing money out the window or into the trash (garbage) bin.
Consumers have limited options for food waste but there are proven solutions.
One can choose the easy route and throw it in the trash to be sent to the landfill, where the decaying food will produce greenhouse gases and a toxic leachate that seeps into the ground.
One can choose to send food waste to an anaerobic digester, which would cost a fee and most people don’t have access to one nearby. And the data shows that’s unsustainable.
Solutions exist where there are user pays billing systems for food and other waste, one can both save money and not choose to throw out food - if you don’t throw you don’t pay; this financial rewards system operates widely across the US and has been very successful with examples, fact sheets and ‘how-to-do-it’ guides here.
The final, best option (and one that is widespread where there are user-pays systems mentioned above) is that one can choose to compost food waste - it’s easy for me, so anyone can do this, too.
If the average household wastes 3 kilogram of food per week, they would be able to save an impressive amount of greenhouse gas emissions from entering the atmosphere by composting instead of disposing into trash.
According to the Environmental and Energy Study Institute (EESI), 21% of U.S. landfills are made up of food waste. Composting is not only great for environmental reasons, but it reduces the volume of waste entering landfills and returns nutrients back to the Earth by producing a nutrient-rich soil that helps gardens and plants thrive.
Just in early June of this year, I started the cheapest compost bin that I possibly could by purchasing a plastic tote at a store for $12USD and drilling holes in it. The value of my completed compost bin that sits in my backyard is much more than that. Just in 6 weeks, my bin already has a thick layer of rich, dark soil and it decomposes my kitchen and yard scraps quickly.
I don’t feel guilt when I have fruit and vegetables that go bad anymore and I am relieved to know that I am successfully reducing my food waste. You can easily compost for a low price and little effort, too.
Next Spring, I plan on starting my own garden for the first time and I know that the compost will be put to good use. If it sparks interest, read about my beginner’s composting journey here.
The U.S. EPA created a food hierarchy to help reduce food waste, and it seems to be helping because I have personally seen big grocery and food companies make more of an effort to donate food that would go bad otherwise. However, we still have a long way to go.
The preferred root solution to food waste is to reduce wasted food by buying food that I know I will eat. This can be difficult if I am shopping on an empty stomach, so let’s make sure to eat before we get groceries so that we don’t over-indulge. A reduction in demand will help us stop over-producing and wasting food.
The next best thing is to donate excess food. Not only should consumers do this, but grocery stores and restaurants should as well. I have seen a lot of unnecessary food waste as I have worked in the restaurant industry for about 10 years in the U.S., when that food could have gone to a food bank or charity. Rather than focusing on profit, companies should also focus on helping others while reducing waste.
If you can’t donate food to people, then the waste can go to feed animals. Chickens, goats, cows, and pigs can eat nearly anything. I have previously called them ‘the living garbage disposal’. Feeding food waste to animals helps save money on food for them and diverts waste from rotting in a landfill - it’s a win-win!
If the solutions so far don’t work, try composting. If no other living being can use the food, this option is helpful in many ways. Compost used on gardens and plants helps the soil retain water and nutrients, saving money and energy on water and fertilizer. There are various simple ways to do it, but it may require a little bit of research so that you know what to add to your compost pile. Composting also helps plants grow faster and recycles nutrients back to the ground. Plus, you’ll end up with free soil!
The last resort is sending your food waste to the landfill. Here, just 3 kg of food waste produces 23 kg of carbon dioxide.
Methane and leachate are other byproducts. More space in the landfill is taken up, and the opportunity to recycle the nutrients is gone. This is the least-preferred process where your money is theoretically thrown away.
Food waste and biomass are important components of our waste systems, and they make the existence of the bioenergy sector possible. However, the bioenergy industry labels itself as clean and renewable energy regardless of the associated deforestation, air pollution, decreased water qualities, and inefficiencies.
More research and data collection are necessary to provide solid data on the downsides of burning and digesting biomass for energy. In the meantime, composting is a simple way to combat climate change and reduce your personal food waste at home. Project Drawdown, a research organization who searches for climate change solutions, estimated that if worldwide composting grew, 2.1 billion tonnes will be kept from entering the atmosphere by 2050.
May your soil be fertile, your plants be healthy, and your soul shine with the lively sun.
Alyssa Noble
Resources
[1] Australian Government - Geoscience Australia. (n.d.). Overview | Geoscience Australia. Geoscience Australia. Retrieved July 10, 2021, from https://www.ga.gov.au/scientific-topics/energy/overview#:%7E:text=Australia’s%20primary%20energy%20consumption%20is,around%20(2%20per%20cent).
[2] Australian Renewable Energy Agency (ARENA). (n.d.). Bioenergy / Energy from waste. Australian Renewable Energy Agency. Retrieved July 12, 2021, from https://arena.gov.au/renewable-energy/bioenergy/
[3] EarthPower Technologies Sydney. (2018, April 19). Renewable Energy. Earthpower. https://earthpower.com.au/
[4] Environmental and Energy Study Institute (EESI). (n.d.). Fact Sheet | Biogas: Converting Waste to Energy | White Papers | EESI. Retrieved July 19, 2021, from https://www.eesi.org/papers/view/fact-sheet-biogasconverting-waste-to-energy
[5] Environmental Protection Agency. (2020, July 30). The Sources and Solutions: Agriculture. US EPA. https://www.epa.gov/nutrientpollution/sources-and-solutions-agriculture
[6] Ferrier, J. M. A. T. (2021, June 24). “Worse than burning coal”: Hunter Energy powers on bid to burn wood. Michael West. https://www.michaelwest.com.au/worse-than-burning-coal-hunter-energy-powers-on-bid-to-burn-wood/
[7] Frost, R. (2021, February 12). Stop burning trees for energy, hundreds of scientists tell EU leaders. Euronews. https://www.euronews.com/green/2021/02/12/stop-burning-trees-for-energy-hundreds-of-scientists-tell-eu-leaders
[8] IFCO Systems. (2021, February 4). Food waste by country: who’s the biggest waster? https://www.ifco.com/countries-with-the-least-and-most-food-waste/
[9] Real Engineering. (2021, June 5). Why Biofuels Are Terrible. YouTube. https://www.youtube.com/watch?v=OpEB6hCpIGM
[10] Student Energy. (n.d.). Biodigestion. Student Energy - Biodigestion. Retrieved June 26, 2021, from https://studentenergy.org/conversion/biodigestion/
[11] Sydney Water. (n.d.). Commercial trade wastewater. Retrieved July 13, 2021, from https://www.sydneywater.com.au/sw/your-business/managing-trade-wastewater/commercial-trade-wastewater/index.htm
[12] U.S. Energy Information Administration. (2021, May 14). U.S. energy facts explained - consumption and production - U.S. Energy Information Administration (EIA). https://www.eia.gov/energyexplained/us-energy-facts/
[13] Valerio Paolini, Francesco Petracchini, Marco Segreto, Laura Tomassetti, Nour Naja & Angelo Cecinato (2018) Environmental impact of biogas: A short review of current knowledge, Journal of Environmental Science and Health, Part A, 53:10, 899-906, DOI: 10.1080/10934529.2018.1459076
[14] World Biogas Association. (2017). Anaerobic Digestion Market Report Australia. https://cdn.revolutionise.com.au/cups/bioenergy/files/jr4jm5qqzrlqfhhb.pdf