Re: [Vo]: Biofuel Bonanza - reality check, please

[Jed Rothwell]

Jones Beene wrote:

Your logical error here --and it invalidates your whole argument is 
the assumption that algae are merely converting sunlight into energy. Wrong.

Or should I say partially wrong. Sunlight is a catalyst for growth 
and is advantageous, but single-cell life will proliferate in total 
darkness with only heat and CO2

I know that. As you said, that would be for the non-photosynthetic 
species. However, this is not a perpetual motion machine. You cannot 
go indefinitely with no energy inputs. The algae converts waste heat 
back into carbon compounds, recovering some of the lost energy. It is 
waste heat from coal, which is ~60% to ~70% of the starting heat. 
Assume the plants convert 10% of that heat back into carbon 
compounds, which would be phenomenally good. That 6% the waste heat. 
So you are reducing power plant energy consumption by 6%. (I expect 
it would be more like 1.2% but make it 6%.)

That's good, but there are plenty of other ways to improve efficiency 
by that extent, and they cost a lot less. There is no way a 
biological species can convert heat or light into a chemical species 
at better rates than that.

Assume that other species of algae in the same ponds absorb sunlight, 
and you get a better rate of return, although it takes a bigger pond, 
as I noted.

- Jed