View Single Post
Old 12-21-2013, 01:32 PM   #23 (permalink)
jamesqf
Master EcoModder
 
Join Date: Jun 2008
Location: Earth
Posts: 5,209
Thanks: 225
Thanked 811 Times in 594 Posts
Quote:
Originally Posted by Old Tele man View Post
Weeks? Nope, during our LONG HOT summer days, probably only hours for regrowth to begin, with a full pond scum in days!

That stuff is ALIVE ! ! !
That pond scum is also a) not very thick; and b) mostly water.

Comes down to basic physics/chemistry/biology. There's only so much energy in incoming sunlight - about 700 W/m^2. Photosynthesis is not very efficient at capturing the energy - way under 10%. (Most PV panels are better.)

That's not saying this couldn't be a useful process, as part of say a sewage treatment plant. It's just not going to be a replacement for petroleum, because those oil deposits represent millions of years of collection.
  Reply With Quote