Global Change Biol. 14, 2000–2014 (2008)

Credit: S. LONG, UNIV. ILLINOIS

The perennial grass Miscanthus × giganteus (pictured right) is photosynthetic royalty. In field tests conducted by Stephen Long and his co-workers at the University of Illinois in Urbana, this sterile hybrid converted 1% of solar energy into biomass that could be harvested to make cellulosic ethanol. That's ten times the standard 0.1% efficiency cited for plants in general.

The team compared Miscanthus with switchgrass (Panicum virgatum), a current US favourite for the cellulosic fuel of the future. Miscanthus produced an average of 30 tonnes of harvestable biomass per hectare; switchgrass produced just 10 tonnes.