Bill Moore in his EVWorld Newsletter (which I highly recommend and his EVWorld Website) has this interesting note about the astonishing efficiency of photosynthesis:

Biomimcry Triumphs Again

On a more encouraging note, scientists at UC Berkeley believe they have figured out how plants and bacteria are so efficient at converting photons of sunlight into energy on which to live. They are using quantum physics.

[Their] findings suggest that excitation energy within bacteria and plants simultaneously tries multiple paths and selects the most efficient one to produce electricity for conversion to plant carbohydrate.
That helps explain the remarkable efficiency of energy transfer in photosynthetic plants and bacteria, which turn more than 99 percent of the absorbed solar energy into useful chemical energy and plant products...
..it suggests that plants and every other living thing reliant on photosynthesis are, in essence, quantum computers. Incoming sunlight poses a question and the plant's photosynthetic works all potential avenues to the answer at the same time until it arrives at a solution...
Adding quantum mechanics makes scientists' thinking about photosynthesis more complex but also complete. That better understanding boosts the likelihood that researchers can move beyond traditional semiconductor-based solar cells to more efficient artificial photosynthetic devices based, as in nature, on pigments and proteins.

All this reminds me of a really good book called Biomimicry by Janine Benyus that explored this whole new area of science where instead of using millennia-old Iron Age technology of "heat, treat and beat", we learn how nature performs its marvels of engineering and chemistry at ambient temperatures and then use it to produce an entirely new economy.

Here's a great quote from that book.

"We are on the brink of a materials revolution that will be on a par with the Iron Age and the Industrial Revolution. We are leaping forward into a new era of materials. Within the next century, I think biomimetics will significantly alter the way in which we live."