Algae already have a vital role in the ecosystem since they can produce oxygen from carbon dioxide in the air through photosynthesis. Algae at a power plant provide the flexibility to capture carbon at the source and reduce the carbon emissions before these emissions reach the atmosphere. As with other plant materials, algae can also be dried or converted into methane to store fuel for later usage.
Researchers at Indiana University are using algae to capture carbon emissions from a power plant on the campus. According to the university, the power plant uses coal, and the more expensive natural gas when its budget allows. Using algae reduces the impact of the fossil fuel usage, although completely capturing all of the carbon from a standard coal plant would require more than a hundred acres of algae ponds. Obviously this is not feasible in many locations, although a power plant at a university in a rural location might be able to successfully set up this type of system.
The University of Illinois is also working on demonstration projects to use algae for carbon capture. According to the University of Illinois, the main advantage of algae is their rapid growth, which requires them to absorb carbon much faster than other plants. Trees and bushes can not match an algal reproduction rate that can double the size of a clump of algae in four hours. The flue gas from the coal plant does first have to be scrubbed of pollutants such as sulfur dioxide which can kill algae, and reduced in temperature to a level that the algae can handle.
Projects in Southern California provide a demonstration of carbon sequestration using algae. A joint project from several research institutions in San Diego, including UCSD, SDSU, and associated research labs, are setting up carbon capture projects in the deserts of Imperial Valley. The algae ponds will require a large amount of space, and the coastal region of San Diego is densely populated and most nearby cities have high land values, but some nearby desert areas are nearly empty because of the extreme heat. Some of the desert regions in this area are part of national parks or military facilities, so the approval process for setting up algae ponds may not always move quickly.