Plants, Light & Excitons

Once in a while, the Economist publishes an article where the reader's comments turn out to be a lot more interesting than the original piece. Here is one  -

TE (3Dec14): HOW PLANTS EXPLOIT SUNLIGHT SO EFFICIENTLY - http://www.economist.com/blogs/economist-explains/2014/12/economist-explains-1?fsrc=scn/tw/te/bl/ed/howplantsexploitsunlightsoefficiently

The main point of contention is this claim by the TE author -

"The very best photovoltaic cells, the kind seen on many roofs, convert sunlight to electrical energy with an efficiency of around 35%; for more affordable cells the figure is closer to 20%. Plants accomplish the same process with about 90% efficiency during the first stage of photosynthesis."

Are plants really so efficient?

A reader contests this claim by quoting three articles:

• Scientific American (2011): http://www.scientificamerican.com/article/plants-versus-photovoltaics-at-capturing-sunlight/
• ScienceMag - http://www.sciencemag.org/content/332/6031/805.full
• Current Opinion in Biotech (2008): http://sippe.ac.cn/gh/2008%20Annual%20Report/Zhu%20X-G.pdf

He then reiterates the original question - where did TE source the '90% efficiency' figure?

No answers yet from the Economist.