PERMACULTURE - Comparing energy conversion of plants and solar cells

Comparing plant and photovoltaic systems is a challenge. Although both processes harvest energy from sunlight, they use that energy in different ways. Plants convert the sun's energy into chemical energy, whereas solar cells produce electricity -the annual averaged efficiency of solar-cell-driven electrolysis is about 10 %
Solar energy conversion efficiencies for crop plants are about 1 %, which illustrates the significant potential to improve the efficiency of the natural system


http://www.physorg.com/news/2012-01-energy-conversion-solar-cells.html