He added that Visa's practices of not allowing use of rival currency conversion systems at merchant outlets also meant that retailers were denied opportunity to share the revenue arising from such transactions.

BBC: Visa sued by Australian competition watchdog

If, on the one hand, you've got biofuels which represent only a half a percent conversion of sunlight, and let's say you've got photovoltaic cells and concentrated solar power systems, the efficiency of solar in terms of pure conversion is 50-100 times greater.

CNN: Biofuels: What do the experts think?