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.
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."