Algae ponds with sol-powered maintenance vehicles.
During the Green Sky Era, expansive fields of algae were grown on viable water sources for a variety of reasons, food production and soil fertilization among these. The primary function of these fields was to clean the atmosphere, accelerating the cleansing of quantum enriched petroleum from the clouds as well as repairing the extensive damage incurred in the old world.
Algae were an attractive way to harvest solar energy because they reproduced themselves, could live in areas not useful for producing food and did not need clean or even fresh water. In addition, they used far less space to grow than traditional biofuel crops such as corn or palm oil.
Microalgae had the ability to fix CO2 using solar energy with efficiency 10 times greater than that of terrestrial plants and solar radiation was the most abundant energy source available. As such, producing H2 directly from solar energy and water as a source of protons and electrons was not only an environmentally friendly and appealing option, but was ultimately one of the only remaining options society had left after the loss of all fossil fuel reserves on G-Day.
The possibility of abundant biofuels was another benefit of algae espoused by Dr. Isaac, yet they were strangely absent in the Green Sky Era. Since such fuels were theoretically compatible with unmodified fossil engines, it's suspected that the vehicles used by Thayer Corp ran on algaefuel; however, this information was not confirmed and Thayer vehicles were not available for public study.
Dr. Isaac's research in the early 21st century changed the face of the globe. Out of all of his areas of study, he was most adamant that proper application of algae would be the saving grace of humanity. He announced his full committal to developing a sustainable algae ecosystem shortly before his disappearance.