Biofuels Are Not the Full Answer, but They Can Be Part of a Solar-Oriented Solution to Our Energy-Climate Dual Crisis

Abstract

Biofuels are part of a trend towards increased utilization of local resources for energy generation, especially those with greenhouse gases' reduction benefits. In this paper, we argue that photosynthesis dependent biofuels -with a practical maximum of 2% energy conversion efficiency -can only satisfy a fraction of the world's liquid fuel needs. Even that cannot be achieved without the deployment of 2nd generation biofuel production processes -still under development -which accept cellulosic and microalgal feed stocks, not food crops. For these feed stocks to be sustainably cultivated, they must be grown on non-arable lands using limited amounts of irrigation water and fossil-fuel based agrichemicals. Additionally, biofuels pose their own unique set of issues to consider such arable land use, water consumption among other metrics. Finally, biofuels should be viewed as just one way of converting sunlight into energy besides other means such as solar heating and photovoltaics, with the latter option realizing an energy conversion efficiency exceeding 10%. By reviewing the potential alternatives to oil and petrol based fuels, it can be seen that biofuels are only a viable replacement when used in conjunction with other renewable energy sources.