bioenergy

biofuels

Pros and Cons of Bioenergy

A while back I shared with you a primer on the world’s oldest source of energy – bioenergy. As a reminder, Bioenergy refers to the process of “efficiently extracting considerable quantities of clean, low-emission electricity from waste.” The waste used as a fuel source is usually agricultural, forestry and municipal wastes, with sugar cane waste (“bagasse”) being the most commonly used source.

Today, I want to look a little deeper at the pros and cons of bioenergy.

Pros


  • Bioenergy a reliable source of renewable energy.  We will never have a shortage of waste that can be converted to energy. As long as there is garbage, manure, and crops there will be biomass to create bioenergy.
  • Bioenergy can be stored with little energy loss.
  • As long as there is agriculture there will be a constant energy source.
  • Bioenergy emits little or no greenhouse gas emissions and is carbon neutral. The carbon that is created by biomass is reabsorbed by the next crop of plants.
  • Bioenergy doubles as a waste disposal measure.
  • Bioenergy crops help stabilize soils, improve soil fertility, and reduces erosion.
  • Bioenergy is a source of clean energy, the use of which can result in tax credits from the US government.
  • Bioenergy reduces the need for landfills
  • Typically, Bioenergy plants are dispatchable, meaning they can easily be turned on or off. This allows more flexibility for electricity grid operators to respond to times of peak demand.

 

Cons


  • Using wood from natural forests can lead to deforestation if the forests are not replanted.
  • The cost of harvesting, transporting, and handling biomass can be expensive.
  • Storing and processing of biomass requires large amounts of space.
  • Some fuel sources are seasonal.
  • May compete with food production in specific cases.
  • Bioenergy plants have a large footprint and require a lot of space, limiting the location options.
  • Some renewable energies, like solar power, are significantly more land-efficient.
  • Bioenergy production typically creates liquid fuels like ethanol or biodiesel that can then be used in applications like combustion engines. However, electric motors can be 2–3 times more efficient than internal combustion engines, which makes bioenergy much less productive in terms of energy for vehicle transport.

As with every energy source there are pros and cons, but as you can see the pros for bioenergy definitely outweigh the cons, especially when compared to fossil fuels.  Bioenergy should be included as part of our larger energy picture that includes all types of renewable energy including solar and wind energy.

Bioenergy is best when it is created using waste materials. These are materials that are by-products of agriculture and farming, downed trees, and our garbage and waste that would be left rotting in a landfill. These waste materials can create valuable energy at a relatively low cost and using these for energy reduces the need for landfills and helps preserve our surroundings while creating another source of power.

 

 

Sources:

  1. Clean Energy Council 2012, Bioenergy myths and facts, Clean Energy Council, Melbourne.
  2. Office of Energy Efficiency & Renewable Energy, Waste-to-Energy, US Department of Energy, Washington D.C.
  3. Searchinger, T. and R. Heimlich. 2015, Avoiding Bioenergy Competition for Food Crops and Land. World Resources Institute, Washington D.C.
  4. Lynskey, Rachel, et al. ClimateWorks Australia, 2020, Moving to Zero: Accelerating the Transition to Zero-Emissions Transport. Monash Sustainable Development Institute, Australia.

What is Bioenergy?

What is Bioenergy?

Bioenergy is energy that comes from renewable biological sources. These sources can be any form of organic matter that stores sunlight as chemical energy. Typical sources include manure, wood pulp, and sugarcane. Although, many more sources are available and currently being researched.

The oldest form of biofuel is wood, typically used for heat. Biofuel is just another name for bioenergy. The sources of biofuel (manure, wood pulp, etc) are called biomass, while the actual biofuel (or bioenergy) is the energy that is extracted from the biomass.

The great thing about bioenergy is that the biomass is typically a by-product of some other agricultural activity. While some crops (including corn, soybeans, and sugarcane) are being grown specifically for biofuel, in many cases are simply using byproducts and waste that would not otherwise be used. Rather than throwing wood pulp or manure on the ground to decompose, we are using that wood pulp to make fuel. The great thing about this is that there is little to no competition between the biofuel sources and needed food sources.

The methane gas that is produced by rotting garbage, human waste, excess crops, and even leftover vegetable oil can be converted to useable biofuel in the forms of ethanol and biodiesel. Not only can we produce fuel for vehicles but in some countries biogas has become a primary source of electricity.

In the US, the DOE is currently researching algae as a great source of bioenergy and biofuel. Oil extracted from algae is processed and converted to fuels that we could use to operate vehicles. Algae takes CO2 out of the atmosphere, which is good for the environment and can eventually reduce our reliance on non-renewable oil sources.

Biomass generates the same amount of energy as non-renewable sources, but because it is renewable it is easily replaced. Biomass creates net zero emissions as long as new plants are being grown to replace those that are being used.

But what about the price?

The DOE has been working to not only find new sources of biomass, but to reduce the cost of biofuels. The DOE reports that once biomass production reaches commercial levels the price will be equivalent to gasoline.