"Hansen proposes burning switchgrass for electrical power..."

In the end, it all comes down to biodiversity. Poison Darts--Protecting the biodiversity of our world

I'd actually suggest burning algae

But not burning it.

Either gasify it, and then use it inside an
"Air Blown Integrated Gasification Combined Cycle" power plant (AB-IGCC) at 55% effeciency.  Reduces water demand by 70%
http://www.netl.doe.gov/technologies/coalpower/cctc/ccpi/ ...

Or better, and cheaper,
Use it inside a direct carbon fuel cell.
Which is essentually a perfected form of a molten carbonate fuel cell.  The whole thing operates at 70-80% effeciency.  And doesn't even need water.
http://eed.llnl.gov/co2/7.php
http://web.archive.org/web/20060117160843/http://www-cms. ...
http://web.archive.org/web/20060525160802/http://www-cms. ...

Both technologies do emit carbon dioxide, but it's in a purified stream.  Making it ideal for sequestration on the cheap.  Or mitigation.  Likely by doing something silly for instance, growing more algae :P

_

The real "problem" with both these technologies is that while they both can effeciently use biomass for electricity.
They also can effeciently use coal.  Any coal.  Including the dirt cheap high sulfur coal.

So we can build them.
But making sure they select a specific fuel type,
that will be the tricky part.