Why bother with algae at 11% peak photosynthetic conversion

[cacofonix]

There was an interesting question raised at a forum I read recently : "If the theoretical maximum photosynthetic conversion efficiency is only 11% (of solar energy), and if solar cells theoretically have much higher (research has shown over 40%) conversion efficiency, why bother with algae?". To that, a person answered that this was because solar energy cannot make liquid fuels while algae can. This answer sounds correct, but in my opinion is not. It is not difficult to see that the electricity from solar panels can be used to heat biomass to produce syngas which can be turned into liquid fuels.

I would think the real answer to that question has to do with yields. Whatever method you use to get liquid fuels, unless you use algae, you do not have enough biomass to produce liquid fuels, period. So that I think is the real reason why the algae route should be tried in all earnest

[dehammer]

1st of all, Id like to know where the 40 percent came from. Best Ive heard is slightly over 10 percent.

Then you have to start talking about conversions of the electical energy. Electrical motors arent that strong yet, so for most vehicles it would have to be a hybred. That requires turning the electricity into something else and then into power, which means a douple energy loss. For instance, hydrogen fuel cells arent 100 percent, so they do lose some of the power there, and then you have the lose from heat in making the hydrogen.

[DR Johansen]

[quote="dehammer"]1st of all, Id like to know where the 40 percent came from. Best Ive heard is slightly over 10 percent. [/quote]

Recent reports about triple layer cells claim 41%+ efficiency, but the are HIDEOUSLY expensive. They make typical thin film cells look practically free!

[cacofonix]

I must add something to my original post (first one) in this thread...

It is possible for solar or wind to actually beat algae for transportation energy, if electric cars become widespread...from what I understand, electric cars give over 100 MPG equivalent. But it is a huge ask to make 750 million vehicles worldwide to convert to electricity...it is not going to happen in our lifetime...