Algae could soon provide a key solution to tackling some of the world’s greatest energy challenges. These tiny photosynthetic organisms can not only remove carbon from the atmosphere, they can also be turned into a sustainable fuel source that has the potential to revolutionize our energy infrastructure.
Why is algae ideal for making fuel?
- Some varieties of algae contain large quantities of oil inside their tiny cells. These algae contain so much oil that biodiesel made from algae could soon meet a large proportion of the world’s demand for petro-diesel.
- Oil produced by algae far exceeds the oil produced by soybeans, palm, or corn when compared on an acre-by-acre basis. For example, algae grown on a single acre has the potential to yield 10,000 gallons of fuel per year, but an acre of soybeans produces only 70 gallons of fuel per year, and an acre of corn produces 230 gallons of fuel per year[sc:1].
- Algae can transform the sun’s light into fuel and removes carbon dioxide from the atmosphere during its photosynthetic processes, providing a sustainable solution to a large share of our current fossil fuel energy woes.
- Algae can grow in salty water, in deserts, and on other land that is unsuitable for the production of other agricultural crops.
- Algae is a carbon neutral source of fuel, as the carbon sequestered during its growth equals about the same amount of carbon emissions that are produced when the algae-based fuels are burned.
- Biodiesel made from algae can be used to fuel cars, trucks, planes, and any other type of vehicle that runs on gasoline or diesel fuel[sc:2].
Why is it taking so long for algal biodiesel to be brought to market?
The greatest challenge for bringing algae-based biofuels to market has been finding a way to harvest and extract the oil from algae to produce fuel in an economically viable fashion that can be done on a large scale.
Researchers have found that the oil is stored between an algae’s cell wall and its membrane, making it a challenge for creating a method that extracts the oil, yet does not destroy the algae cell itself. However, research is currently being done that seeks to find solutions to this problem, and it has been estimated that large scale cultivation and production are likely to begin within the next 4-5 years[sc:1][sc:comma][sc:3].
The process of how algae is made into fuel
- Outdoor man-made ponds, “raceways,” are used to cultivate a crop of new algae every few weeks.
- The oil is extracted after the cell structure of the algae is broken down through the use of solvents or soundwaves (known as “sonification”).
- After the oil is refined, it is further processed in a biorefinery. This processing could also be done in a traditional oil refinery in the future. In the future, algae farms could even be built next to power plants that currently process fossil fuels, using the CO2 exhaust from the power plants to feed the algae in the ponds.
Over 100,000 different strains of algae exist in the world. Some strains grow best in salt water, some grow best in fresh water, some grow best in warmer conditions, and some grow best in cooler environments. Scientists are currently testing different strains of algae to determine the best ones for fuel production and to develop the most efficient algae farming practices[sc:2].
Where algae biodiesel is practical and where it is not?
While algae biodiesel is a great energy solution that can help propel us forward into a clean energy future, it is not a magic bullet that can fix all of our fossil fuel energy woes. The energy resources of the future are likely to be diverse, and will include a variety of biofuels as well as other renewable energy resources.
For example, solar panels are an ideal solution for providing electricity to homes and other buildings, but they don’t really work to power heavy trucks. Electric cars can use batteries, but airplanes need a different source of energy. For airplanes, heavy trucks, and other heavy vehicles, algal biodiesel provides an ideal substitute for petroleum fuel[sc:4].