By: Everett Lee, Diego Garcia-Camargo, Gavin Kendal-Freedman, and Amay Bansal
Special thanks to Jake J. Valenzuela
Tools used: Google Colab, Python (Pandas, Seaborn, MatplotLib), NetLogo, Github
Estimated time: 1.5-3 hours
Through this activity, Students will:
Be introduced to the process of data cleaning, management, and analysis as well as have the opportunity to explore a complex data set in a coding environment.
Use data visualization to find correlations between factors of algae cultivation and identify possible causes for these relationships.
Understand the different pros and cons of clean laboratory data and real-world data, as well as how these differences affect data processing and analysis.
Participate in the process of deriving useful information from scientific data to be included in the creation of a scientific model.
Understand the limits of an algae cultivation model, why the limits may arise, and the usefulness of the model in spite of these limits.
Why Algae Biofuels?
Introduction: Energy Usage Today
In the United States, fossil fuels make up 62.7% of energy consumption whereas renewable energies only make up 17.5%. Fossil fuels are taken out of the ground for energy production and release carbon dioxide gas through combustion. Because fossil fuels are formed over millions of years, the carbon released has been separate from the carbon cycle for millennia. The reintroduction of ancient carbons causes an imbalance in the carbon cycle and disrupts the balance of the global ecosystem through exacerbating the greenhouse effect. The greenhouse effect is a natural phenomenon whereby heat from the sun becomes trapped in earth's atmosphere by gases such as carbon dioxide. Ancient carbon released into the atmosphere raises the earth's temperature above normal, causing climate change. The effects of carbon dioxide on the ecosystem do not stop at rising temperatures. For example, an overabundance of carbon released into the atmosphere causes Ocean Acidification, where gaseous carbon is dissolved into the oceans as carbonic acid, lowering the ocean's pH and harming many organisms.
Not only are fossil fuels bad for the environment, they are also non-renewable. Fossil fuels come from ancient biomass deposits deep in the earth’s crust. Through millions upon millions of years, dead plants and animals decompose into hydrocarbons. At the current rate of usage, humanity is using fossil fuels much, much faster than they are being replenished. While having been the source of much technological advancement for humankind, eventually the fossil fuel deposits deep beneath the surface are going to run out, and we are going to have to find an alternative.
wind and solar power. 
Fossil fuels being pumped from deep underground. 
There are many different solutions that are being developed and used around the world: nuclear energy, renewable energy (such as wind, solar, and hydro), natural gas, and many more. Some downsides to such solutions are a lack of feasible scaling, problems with effective transportation, or being less efficient than fossil fuel counterparts.
For more background on fossil fuels and the carbon cycle click here.
Watch this Ted-Ed video for more background on the transition to renewable energy.
Algae Biofuels and Carbon Neutrality:
As a response to the overuse of fossil fuels research is being done on finding effective, easily transportable, renewable, and carbon-neutral energy sources. One category of alternatives is biologically-based fuel sources known as biofuels. Biofuels are defined as "any liquid fuel derived from biological material" (What are Biofuels?). Generally, Biofuels like ethanol are less efficient than fossil fuels, and are blended with petroleum-based gasoline for a cleaner-burning product (Biofuel Basics). "Drop-in" biofuels are able to replace fossil fuels because they are rich in the hydrocarbons that are burned in petroleum-based fuels to produce energy. Algae can be cultivated to produce a high amount of hydrocarbons through lipid production. In this activity, we will be looking at the production of algae-based Biofuels or Algae Biofuels.
During cultivation, algae photosynthesize carbon dioxide, sunlight, and water, to produce energy. This energy is then used for general cell function and growth (i.e. the production of proteins, carbohydrates, and lipids). In this case, the maximization of lipids (and thus hydrocarbons) harvested is key. Certain steps can be taken to maximize the amount of lipids produced and we will explore one these steps as well as other growth strategies later in the activity. After cultivated the algae can then be harvested and converted to a crude oil (“green crude”) that can then be refined and used as a fuel source.
Although algae biofuels are essentially interchangeable with fossil fuels in their use, their key difference lies in their effects on the environment. The concept of Carbon Neutrality relates to the idea of a carbon footprint, or the amount of carbon released into the atmosphere by an entity or action. For something to be carbon neutral, it must take the same amount of carbon as it releases (CO2 released - CO2 consumed = 0). Consider the use of fossil fuels to power a car. When a fossil fuel is used, carbon is released into the atmosphere and no carbon is consumed leading to an imbalance in the atmosphere. When it comes to algae biofuels, on the other hand, whatever CO2 green crude releases into the environment, was already taken in through photosynthesis. Therefore, if a car is powered by algae-based fuel, driving becomes a carbon-neutral action. Algae biofuels are thus referred to as carbon-neutral or near-carbon-neutral energy sources. This difference also means that algae biofuels maintain the atmosphere's equilibrium and are a clear-cut replacement for fossil fuels.
A zoomed in image of a leaf 
Image by Diego Garcia-Camargo
Benefits of Algae Biofuels as compared to other Biofuels:
We have already discussed some major benefits to algal biofuels: The fact that they are carbon neutral, renewable, and are easily transportable. However, there is one more major benefit to algal biofuels that sets it apart from other biofuels that come from crops like corn and soy. When it comes to biofuels more generally, the biggest tradeoff is the use of farmland that could otherwise be used to produce foodstuffs. When faced with the amount of biomass needed to meet current energy needs, the "land required is so great that we cannot simultaneously meet our energy needs and grow enough food" (Disadvantages of Biofuels - Land Use). However, when compared to other biofuels, algae produces 10-100 times more fuel per acre. Additionally, Algae biofuels do not require the nutrient-rich soil that their biofuel counterparts also do and can be grown in areas unfit for traditional cultivation, such as deserts. These advantages allow biofuels to be produced without hindering food production to the same extent as soy, sugarcane, or corn derived biofuels and establish them as the biofuel with the biggest potential for mainstream use.
A chart comparing Land Area vs Fuel Output of various energy sources 
To begin with this activity, head over to the Algae Biofuels GitHub by clicking the button below and go to the Introduction page of the linked Wiki.
1. A microalgae farm. The oval-shaped ponds are called raceways . [accessed 2020Aug.10]. http://news.algaeworld.org/a-microalgae-farm-the-oval-shaped-ponds-are-called-raceways/
2. The Algae Testbed Public-Private Partnership ATP3 | NREL. [accessed 2020Aug.10]. https://data.nrel.gov/submissions/76
3. Green Algae Biofuels - Baliga Lab. [accessed 2020Aug.10]. https://baliga.systemsbiology.net/projects/green-algae-biofuels/
4. Knoshaug, E. P. et al. Unified field studies of the algae testbed public-private partnership . [accessed 2020Aug.10]. https://www.nature.com/articles/sdata2018267
5. What are Biofuels? | Biofuels. [accessed 2020Aug.17]. http://learnbiofuels.org/what-are-biofuels
6. Biofuels Basics. energy.gov. [accessed 2020Aug.17]. https://www.energy.gov/eere/bioenergy/biofuels-basics#:~:text=The%20two%20most%20common%20types,first%20generation%20of%20biofuel%20technology.&text=The%20Bioenergy%20Technologies%20Office%20(BETO,and%20algae%2Dbased)%20resources.
7. Disadvantages of Biofuels - Land Use - Biofuels. [accessed 2020Aug.18]. http://biofuel.org.uk/land-use.html
8. Wilensky, U. (1999). NetLogo. http://ccl.northwestern.edu/netlogo/. Center for Connected Learning and Computer-Based Modeling, Northwestern University, Evanston, IL.