Center for Marine Biodiversity and Conservation

The global economy is heavily dependent on the consumption of energy. The use of fossil fuel, from which 80-90% energy is currently produced, is considered unsustainable because of the depleting reserves and hazardous environmental impacts. Energy derived from renewable biomass feedstock provides a sustainable alternative that has the potential to replace fossil fuel, and avoid negative environmental impacts by reducing carbon dioxide emissions. However, the production of bioenergy is not yet economically feasible due to the high generation cost.

In this paper, a model was developed to investigate the feasibility of a hypothetical bioenergy project that uses the combination of marine microalgae-derived biogas and petroleum diesel for electricity generation and recycles carbon dioxide for algae cultivation; Hawaii was used as an example in this model to explore potential policy solutions to bring forward the commercialization of bioenergy. Results calculated from the model indicate that when the algae cultivation system operates at a productivity of 20 VS (volatile solid) g m2 d-1 captures 70% of the carbon dioxide generated from the system, and the price of diesel exceeds $2.10/Gallon the project is more economically feasible compared to the equivalent electricity generation project using only diesel. Assuming the project is located in Hawaii, and that the productivity of biomass is as low as 10 VS g m2 d-1, a $39/ton carbon dioxide reduction subsidy can make the project economically feasible.