Biomass energy is a renewable energy source derived from biological materials that are called biomass. As with all renewable energy sources biomass energy has its pros and cons.
The most common sources of biomass are wood, waste of biological form (i.e. sawdust), animal manure, landfill gasses, biofuel crops (i.e corn) and garbage (Municipal Solid Waste). It should be noted that in the case of garbage and the waste to energy processes (i.e. burning municipal solid waste for the production of heat and/or electricity) it can only be considered renewable if the fuel used is purely of biological origin and does not contain any non-organic materials otherwise it cannot be considered sustainable.
In effect biomass energy results from sun. The circle of biomass (see picture 1) starts from plants that use sun’s energy in their photosynthesis process that makes them grow and thus store energy into their leaves and roots. Moreover, animals, that in many cases are used as biomass fuel, in their turn consume plants to help them grow. Biomass is then harvested by humans and gets processed in order to be used as fuel to produce energy.
Biomass energy is one of the first forms of energy used by humans. The burning of wood for cooking or to produce heat for example is one of the most ancient usages of biomass energy from humans that takes place nowadays in many parts of the world on a daily basis.
Biomass Energy Pros
- Renewable energy. Biomass energy, as already mentioned, is renewable meaning that we can keep exploiting it indefinitely by simply keep replacing properly the fuel that we used to produce it i.e. sugracane, trees, corn etc.
- Carbon neutrality. There are various environmental concerns regarding biomass with the main one being the fact that during its production carbon dioxide is released in the atmosphere. This is indeed true but, since biomass is a process that involves biological material, such as plants, the carbon dioxide amount that is emitted is the one that was captured during the growth of the various source materials and is released back during their use as biomass fuel. Therefore, if for example the plants that were used for producing biomass energy are from a crop (i.e. corn or sugarcane) that was designed especially for this purpose are replanted it has no additional burden for the environment since the emitted CO2 amount will be recaptured. In the event though that biomass energy produced is a result of deforestation then there is an increase in the amount of CO2 in the atmosphere and thus it cannot be considered renewable. Therefore, the rate that we use biomass to produce energy versus the rate we grow it back is essential in making it carbon neutral. In the case of traditional fossil fuels on the other hand, such as coal, the amount of carbon dioxide released was stored away from the atmosphere millions of years ago and thus its combustion does increase the current concentration of CO2.
- Energy Storing. One of the greatest advantages that biomass energy has, as opposed to other renewable energy sources, such as wind and solar, is the fact that its fuels can be stored and used to produce energy at the moment that is needed.
- Cost. The price of biomass fuels are mostly in parity and in many cases cheaper than other fossil fuels. Thus there is no need for subsidies which is one of the biggest arguments used against solar and wind energy in the ongoing debate.
Biomass Energy Cons
- Harmful emissions Even though biomass energy production is carbon neutral it involves emission of other gases that can be harmuful to the environment. In specific, the production of biomass energy causes the release of nitrous oxide (N2O) and methane (CH4) that cannot be reabsorbed by simply replanting the biological material that was used. As a result Green House Gases accumulate during the production of biomass energy something that doesn’t happen with other renewable energy sources that can be completely clean.
- Storing. One of biomass energy advantages is the fact that it can be produced on demand at the same time though this translates into huge warehouses for storing the biomass fuel which adds a significant production cost.
- Biofuels controversy Biofuels originated from corn, soybeans etc have been accused for driving food prices up since arable land that was once used to feed humans is now used to produce fuel.
Biomass energy is renewable and can be sustainable if we use it wisely. It does have its disadvantages but it is still a much better solution from fossil fuels and it can also help us reduce our dependency from fossil fuels imports.