That has yet to be an energy source that comes without some drawback. Even solar energy, the long-touted saviour of the ever expanding human appetite for energy is decades away from being feasible on a large scale and without the impact that comes from manipulating toxic chemicals into PV panels. Do biofuels also have drawbacks? Of course they do. The real question is, do the advantages of biofuels outweigh the drawbacks or at least put them ahead of fossil fuels in the balancing act? To understand, a quick look at the pros and cons of fossil fuels is necessary. After that, this article will look at the advantages of biofuels.
The Advantages and Disadvantages of Fossil Fuels
Humans have been burning fossil fuels for over a century and a half now and in that time we have become very good and finding, extracting, and refining the crude product from which these fuels are made. So, advantage number one for fossil fuels would have to be infrastructure. The knowledge to exploit these resources and the tools to make that happen are both well-defined, in place, and in use on a daily basis.
Probably the most substantial benefit to come from fossil fuels is their energy density. Fossil fuels carry enough energy in a small enough space to make them very practical for a number of uses, most importantly transportation. The same cannot be said for many biofuels or for electricity, which requires large and cumbersome batteries that generally only provide a fraction of the energy density of fossil fuels.
Finally, fossil fuels are inexpensive and have uses beyond their applications to energy. They offer raw material for industries ranging from plastic to pharmaceuticals to laboratory science. Their applications go well beyond energy.
Of course, the disadvantages of fossil fuels are well known. They are in limited supply, which means sooner or later we will run low and prices will begin to climb. Eventually they will disappear altogether. Even if this problem could be addressed, it would not eliminate the huge environmental impacts that fossil fuels have, including everything from oil spills to global warming to acid rain.
The best way to view fossil fuel energy is as the source that brought humanity into the twenty-first century. They aren’t 'evil' but it is time for society to transition to alternatives for the sake of the environment and because, eventually, the current source of our energy will run dry. These are just some of the reasons humans have turned to biofuels.
Availability of Biofuels
Unlike fossil fuels, biofuels are a renewable energy source. Because they are derived from crops that can be harvested annually, or in the case of algae monthly, biofuels are theoretically unlimited. Despite this surface appearance of unlimited availability, biofuels do have restrictions. Restrictions are treated in more depth in disadvantages of biofuels, but a brief consideration reveals that the threat to the food supply is the major limiting factor to the quantity of biofuel feedstock can be grown.
This limitation also means that certain feedstocks are out of the running for replacing fossil fuels. Crops like corn and soybeans do not produce enough energy per acre of crop to meet current fuel needs, which are only expected to increase, without seriously threatening the food supply. For this reason, higher energy density crops like algae and Jatropha are being considered.
An abstraction of availability is delivery infrastructure. After all, a fuel that it easily produced but not easily transported (like electricity from solar panels in the Sahara) is still limited in its availability. Biofuels are similar in many ways to fossil fuels. They are liquid at standard temperature and pressure, have reasonably high energy densities, and can be distributed with only minor modifications to existing infrastructure.
Speaking of modifications, biofuels have the advantage that they can be burned in standard internal combustion engines with only minor modifications to the rubber in fuel lines and gaskets. This is in stark contrast to fuels like hydrogen or electricity, which requires complete redesign of everything from the engine to the transmission.
So, in terms of availability, biofuels have a big advantage as they are at the top of the list of alternatives and, as supplies slowly dwindle, will also top fossil fuels. Availability may be the driving force in adoption of alternatives energies, making biofuels the next logical choice while other alternatives are still under development. In fact, biofuels are already showing up in full fuel engines, in countries like Brazil, and as additives to standard fossil fuels in almost every nation. The transition is likely to be subtle but slow as more and more fossil fuel is replaced with biofuel. The U.S. military, for instance, plans to replace 50% of its fossil-based jet fuel with biofuel alternatives by 2016.
This category is tricky because biofuels are very similar to hydrocarbons and have some of the same emissions problems that standard fossil fuels have. They can, however, be more environmentally friendly if care is taken in how they are produced and distributed. It is also the case that biofuels have an impact on the environment other than emissions, so we must consider several different subcategories under this heading.
Spills and Surface ContaminationBiofuels are not 100% safe but they are much safer than fossil fuels. If you were to spill a large quantity of biofuel into a concentrated area, it would likely kill living organisms and contaminate surround soil or water. However, the scale of the impact would be orders of magnitude smaller than with fossil fuels.
First off, biofuels are biological molecules and this means they are biodegradable. Bacteria and other organisms that live naturally in the soil and water are able to use biofuel molecules as energy sources and break them down into harmless byproducts. This means that even though concentrated biofuel spills can kill things like plants and smaller animals, they will not persist in the environment and cause damage or make an area uninhabitable for long periods of time.
Sulphur and Atmospheric ContaminationOne of the major problems to arise from burning fossil fuels, especially coal, is acid rain that comes from the high sulphur content of these fuels. Biofuels can be produced in ways that completely eliminate sulphur and thus can eliminate this component of acid rain.
On the other hand, biofuels tend to contain high levels of nitrogen, which can form compounds that also lead to acid rain and atmospheric contamination. On the whole, the net impact on acid rain production is usually negative, meaning biofuels can reduce acid rain. Importantly, biofuels can be carefully produced to ensure that contamination is as low as possible, giving them an edge over fossil fuels because it is easier to avoid contamination in the production phase than it is to remove contaminants during refining.
Greenhouse Gas (GHG) Emissions and Global WarmingThis is the area in which the most care must be taken in how biofuels are produced. If biofuels are produced in the “correct” way, they can greatly reduce greenhouse gas emissions. If produced incorrectly, they can increase emissions. Here is how.
First, plants use carbon dioxide, the major greenhouse gas of concern, to grow and produce food. So, plants are able to reduce the amount of carbon dioxide in the atmosphere and thus decrease global warming. Biofuels, when grown from plants, can thus offset their CO2 admissions because they take up the gas during growth that is produced when the fuel is burned. The idea is that if there is a one-to-one relationship, then the gas produced is the same as the gas taken in and there is no net impact on global warming. The problem is that achieving the one-to-one ratio may be impossible.
For starters, energy has to be invested into growing the crop itself. This energy comes in the form of planting seeds, tilling and preparing the ground, and importing water and nutrients. As it turns out, you cannot get something for nothing and so many crops require more energy input than they give out in the end. In other words, if you take into account the GHG emissions that occur just to grow the crop and add that to the greenhouse gas emissions from burning the crop, there is more CO2 produced than taken up and global warming worsens. As of yet, there is no good solution to this problem. Many companies are looking to invest energy in the form of sunlight so that there is no GHG emitted during the production phase. There is still a net energy INPUT, but no greenhouse gas is produced. This seems to be most feasible with algae.
The other problem to consider is land use. If land is cleared to grow a biofuel, then the plant life that existed there is eliminated. This problem is considered in more detail in the disadvantages of biofuel, but the main point is that carbon is produced to clear that land and the benefits of the plants on the land are lost. By some estimates and depending on the type of plant life removed, the impact could be a carbon debt that can take as long as 500 years to pay back. Again, the solution to this problem may be algae.
If the above technical impediments can be overcome, then the net impact of biofuels on the environment can be limited. In such a scenario, the greenhouse gas emissions and impact on global warming will be far lower with biofuels than with fossil fuels. The feasibility of achieving this advantage remains to be seen.
This advantage is obvious and has no immediate drawbacks. If a country has the land resources to grow biofuel feedstock, then it can produce its own energy. This ends any dependence on fossil fuel resources, which are geographically limited to only a few places in the world. Given the amount of conflict that occurs over fuel supplies and prices, energy independence should have a net positive effect.
Despite this utopian ideal, the reality of biofuel energy independence is not so clear cut. First, not every country has the resources needed to grow biofuels. Many countries do not have the land area, access to water, or ability to produce fertilizer for crops and thus would still need to rely on others for their fuel to some degree.
As a second point, the shift in power could have a highly disruptive effect. First, national economies around the world depend on oil revenue to survive. Many Middle Eastern countries have a vested interest in ensuring that oil remains important and profitable given that as much as 90% of government revenue in these places comes from oil exports. To compound this problem, most of these countries would go from net energy exporters to net energy importers, further damaging their economies and forcing them to completely shift their industrial and commercial focuses.
Major Oil Producing Regions (From: CIA World Factbook and in Public Domain)
Finally, other countries with vast land resources and access to good growing conditions stand to become hew hotbeds of conflict. It is unlikely that the fight over energy will cease given that the location of suppliers will change and not everyone will be able to meet their energy needs from biofuels.
Dry Regions of World (From: USDA and in Public Domain)
In the map above, dry regions are shown in grey. Red regions indicate areas that are not considered desert, but are at high risk of becoming desert. Blue regions are too cold to grow crops.