Along with the technical revolution in energy production comes a growing body of research into "techno-economics". Two articles just published in Biotechnology for Biofuels this month present economic models of cellulosic ethanol production.

Stefano Macrelli and colleagues explore how cost parameters affect the profitability of a second generation fermentation process, when used in tandem with first generation production. They model fourteen scenarios, to optimize integration of both first and second generation processes in a single plant. The profitabilty of the optimum processing scenario is found to be highly sensitive to the electricity selling price and to the cost of leaves and enzyme, and such a plant would require subsidy to compete within Europe. The authors predict that it would already be profitable, without subsidy, to run a plant using their model in Brazil.

In a separate article, Kristin Vicari and colleagues look at the uncertainty in the experimental data, upon which yields are predicted in techno-economic models. Their analysis of the input variables, used in modelling lignocellulosic ethanol production, identifies process parameters that cause a $0.15/gal uncertainty in the minimum ethanol selling price (MESP). The result is a framework of key measurements that can be made more accurate, in order to reduce uncertainty in the models and so help to avoid investment risk.