I just came upon an article that discusses an interesting alternative energy technology (http://biomassmagazine.com/articles/1674/solar-powered-biomass-gasification/). This particular idea involves using solar concentrators to drive the pyrolysis of biomass and to achieve the high temperatures necessary for producing syngas (H2 and CO). The benefits of this approach appear to be (1) greater thermal efficiency because some biomass does not have to be combusted to provide the heat required, and (2) a fuel gas that is not diluted by nitrogen. This latter feature allows for the production of liquid hydrocarbons through the Fischer-Tropsch process discussed here: http://en.wikipedia.org/wiki/Fischer%E2%80%93Tropsch_process. Solar thermal energy can also be used in the process heat required. The former article also discusses the prospect of culturing algae as a feed stock. This idea seems appealing to me because most research into using algae for the production of biofuels focuses on selecting (or engineering) a strain for high oil production directly. Unfortunately, when organisms are selected to express specific traits it often comes at the expense of the general viability of the organism. Gasification might allow for using the hardiest strain.