Last month, Professor Mark Z. Jacobson at Stanford University conducted a scientific comparison of a handful of energy sources including some alternatives like wind, solar, and tidal. In this study, looked at different aspects of each energy source and compared them in categories such as water usage and problems with intermittency.
However, throughout this whole comparison, corn ethanol is the only biofuel that is analyzed, a biofuel which has already been decried as an inefficient and ultimately environmentally detrimental source of energy. On the other hand, algae biofuels aren't even mentioned even though they are considered to be a rising star in the world of alternative energy.
We'll try to remedy Professor Jacobson's omission by trying to place algae in each of the different categories he uses to hopefully highlight its overall benefits. Notably, we won't be able to use the numerical analysis that Professor Jacobson offers. The examples presented here will at least give you an idea of how algae might compare to the results of Professor Jacobson's analysis, and the titles of each section relate to his report.
There are two main technologies utilized to grow algae. One way that seems to be the main focus of startup companies is growing one specific strain of algae in a bioreactor. Some companies using this method are Solazyme, GreenFuel, and OriginOil. For those not familiar with a bioreactor, an explanation of the technology can be found here.
The other way that algae can be grown is in an open pond. In comparison to the bioreactor method, algae farmers are hard pressed to keep "contaminate" strains of algae from growing in the ponds. Aquaflow Bionomic Corporation is one company using this method and has opted to use wild strains of algae to convert to biofuel instead of worrying about a specific strain of algae to harvest. In fact, Aquaflow has been quite successful with using wild algae and has even created key jet fuel components from it.
One of the great things about algae based fuels is that the resources available to produce them are practically unlimited. All you need is CO2, water, and sunlight. With such simple requirements, one might wonder why it is taking so long to see a commercialized process for its production. However, the main reason for the delay seems to be the current high cost of producing algae. Luckily, quite a few biofuel startups are saying that they will be able to produce commercially competitive fuel quite soon and Aquaflow Bionomic Corporation has already created samples of "green crude" at commercially competitive prices.
3. Effects on climate-relevant emissions
It would seem that algae biofuel in itself is a carbon neutral fuel (the carbon it takes in will be released again when it is burned). However, when you factor in the processing plants that would have to be constructed in order to convert algae into the different qualities of fuel (aviation, gasoline, etc.), the supposedly carbon neutral fuel might lean towards the carbon emitter side of things. However, one must remember that no technology is completely carbon neutral when you look at it this way. Even solar panels and wind turbines were mostly likely produced in a plant using energy from CO2 emitting power plants.
Though it is hard to say exactly how much carbon might be emitted because of algae, it would seem logical to assume that those producing algae from open ponds emit less CO2. I say this because open ponds only require the algae to be collected and processed into fuel. Bioreactor plants, on the other hand, will constantly be using energy to move the algae through the reactor system. Couple that with the costs of processing it and the bioreactor plants would have presumably used more CO2 derived energy than open pond production.
The good news is, when looking at the CO2 emissions from both algae production methods in comparison to traditional energy sources like coal, one will find those emissions related to algae are negligible.
4. Effects on air pollution emissions and mortality
Once again, other than the construction of the algae plants, maintenance, etc., the only emissions will be when the algae fuels are burned. I tried to find the exact chemical makeup of the emission from algae biofuels when burned but was unable. The only other possibility of emissions I found was the chance of natural sulfur dioxide emissions from the growth of algae. However, as the article states, these sulfur dioxide emissions are minimal when compared to manmade sources.
Also, the use of algae doesn't seem to have the effects on mortality that fuels like nuclear energy or ethanol have. First off, the handling of algae doesn't have the same potential to harm anyone like the handling of uranium for nuclear power plants. Therefore, the handling and transportation of algae isn't going to pose a problem in itself. Also, the food vs. fuel debate isn't applicable with algae as it is with ethanol. Algae isn't a food source so each pound of algae going towards fuel production doesn't mean a pound of food not going onto someone's plate.
5. Land and ocean use
Another great thing about algae is that it is such a high producer of energy in such a limited amount of space than any other biofuel out there. For example, it has been estimated that the United States only needs enough algae farms equaling the size of Maryland to produce 100% of its fuel for transportation needs (Emphasis added):
Companies in California, Texas and Florida are leading the effort to produce and market fuel from algae. PetroSun of Rio Hondo, Texas, began producing fuel in April 2008. The company says it can produce 4.4 million gallons of oil every year from its 1,100 acres of algae ponds - roughly 4,000 gallons per acre. In contrast, one acre of corn produces about 330 gallons of ethanol, according to industry reports.
Algae is considered one of the most promising options for future biofuel production for a variety of reasons. Algae yields significantly more energy per acre than its closest biofuel competitors. Algae does not require fresh water or arable land. Experts say that if all of the fuel in the United States were replaced with algae biofuels, an area no larger than the state of Maryland would be required to produce it - making algae a much more efficient user of land than corn or soy ethanol, for example.
If these claims turn out to be correct, algae would prove to be the very best source of biofuels available. Some have even purported that "ponds with a combined total acreage equal in size to Belgium would be enough to meet all demands from commercial airlines across the globe."
Both of these estimated land areas are extremely small in comparison to some of the land needed by other biofuels currently on the market. To see just how much more efficient algae is compared to other biofuels with regards to land usage, check out the chart at left. (source article viewed here). Also, notice that algae received both "low" and "high" marks where it is beneficial. For an explanation about algae's water usage, check out "6. Water Supply" located below.
6. Water supply
At this point, many people will probably be worrying about the increased water usage required by algae and the strain it could potentially place on the world's aquifers. Fortunately for the world, algae cultivation does not have to affect the world's freshwater supply. In fact, unlike other biofuels, algae can be grown in anything from wastewater to saltwater.
By using these two types of water, algae puts itself in a league of its own. Most traditional biofuel crops like corn, soybeans, or jatropha, need freshwater for their growth. By utilizing wastewater, algae actually uses something that would essentially go to waste and helps to filter out the pollutants in the process. Therefore, there are two benefits to using algae: one, it helps to filter out pollutants before releasing the water into the environment and two, the algae can be harvested and used for biofuel production. This isn't a revolutionary idea; some countries are already looking into algae wastewater treatment with the UK being one of the latest.
Also, with the saltwater being another potential water source for algae, one will never have to worry about algae's growth affecting the water supply.
Using algae as a fuel source will most likely have an effect on wildlife and the environment, though it won't be nearly as big in comparison to other fuel sources. To start off with, it has to be understood that no matter how ‘environmentally friendly' an energy source may be, it will still some have negative effects on the environment.
With that in mind, the way that algae farms will affect the environment will depend on what system is used to cultivate it. If it is a closed system, like a bioreactor, one of the only impacts on the environment will be the development of the land needed for the farm. On the other hand, if the algae farm utilizes the open pond system, there may be additional environmental impacts in addition to the land usage. For example, the farmers may have to use some sort of system or additives to ensure that nothing is eating the algae growing in the ponds.
However, compared to coal and nuclear plants that produce toxic waste that could leak into the surrounding environment, algae can actually reduce the amount of waste by its use in the wastewater treatment process. Also, the leftovers from oil extraction can actually be used as animal feed or human supplements, greatly reducing, or essentially eliminating, any solid waste from algae fuel production.
Overall, whatever environmental impacts that algae may cause will most likely be offset by the extreme benefits like extremely low amount of land and water used to produce extremely high amounts of energy. It really is hard to argue against the ‘environmental friendliness' of an energy source that offers the USA 100% energy independence by using marginal lands that total less than .005% of our country's landmass.
8. Energy supply disruption
Another great thing about algae production is that it can be spread out across the entire country. With the high yields per acre that algae offers, even smaller farms could be fairly lucrative. What this means is that it would be hard to disrupt the supply of energy these farms would produce.
Even though it would probably be hard to disrupt, it's worth taking a look to see which of the two systems would be more prone to disruption. Right off the bat, open ponds would seem to be the ones more prone to disruption, definitely if the ponds are trying to grow only one type/strain of algae. These ponds are open to the elements and can easily experience contamination that could cause crop failure.
But if the open ponds grew multiple wild strains of algae, there might be certain benefits that could protect them from disruption. For instance, if something gets into the pond and starts killing one kind of algae, another kind could possibly survive and flourish. These wild strain ponds could have better resiliency even though they are more open to the elements. Overall, though, these open ponds do run a higher risk of mass contamination that could kill everything.
On the other hand, companies using the bioreactors seem to have protected the algae growing process. The reactors help to protect the algae from contamination and any other unwanted substance being introduced. With this in mind, it would seem that algae bioreactors are the way to go. However, the reason that not everyone is using this process is the fact that bioreactors can greatly increase the costs of operations.
With algae, problems with intermittency can easily be addressed. Since the only things that algae needs to grow are basically water, CO2, and sunlight, the farms just have to be set up in such a way that they receive these necessities all year. As long as there is sunlight and the water the algae is growing in doesn't freeze, this stuff can grow almost anywhere year-round. Of course, the higher the latitude and altitude, the more energy it's going to take to keep the water from freezing year round. Therefore, there might be a point where the energy produced by the algae doesn't displace how much energy is used to keep the ponds in a liquid state.
The only other problems with intermittency would come from the actual oil refineries that would have to take the "green crude" and produce either gasoline, aviation fuel, or other products. However, as traditional refineries haven't caused too many problems with regular petroleum, I don't foresee any additional problems with algae.
10. Large scale application
What makes algae better than other potential fuel ideas like hydrogen for large scale application is that algae can be converted into fuel that is compatible with our current fuel infrastructure. One algae biofuel company, Solazyme, is already on the road to getting there. Just last fall, the company announced that they had created a jet fuel from algae that meets the "ASTM D1655 standard for Aviation Turbine Fuel." What this means is that the fuel could be used in most commercial and military engines as is. By not having to change our fuel infrastructure, the public will be more willing to accept and support these new types of fuels.
Also, the ability to grow 100% of the United States' fuel needs in the area the size of Maryland alone makes it a good choice for large scale application. Other biofuels don't even come close. Ethanol, for instance, needs 2x as much available cropland we have in the United States just to meet ½ our fuel needs.
However, even thought it might seem like a no brainer to use algae, the current technology is not quite there yet. The good news is that they are getting very close. For example, companies like Algenol have announced that 2009 will be the year they begin commercial sales and in the past month we have seen successful test flights using partial algae fuels.
It's also important to note that algae biofuels are not just a localized phenomenon. Instead, you can see them popping up across the United States in places like Missouri, New Mexico, Virginia, and Nevada and across the world in countries like China, New Zealand, Australia and possibly even Brazil. This all goes to shows that algae biofuel is here to stay and has a transregional and transnational appeal to those who search for the newest alternative fuel source. In conclusion, it is hoped this article has shed some light on how algae biofuels match up with other energy technologies.