Biofuels created from algae are an interesting and creative energy source, but they are not economically feasible at this stage in their development. The primary reason for this is that the amount of land required to support sufficient algae biofuel growth and production is much too large in relation to the economic output from the land.
Biofuel is a wonderful thing, burning it makes the area smell like frenchfries when its burned, rather than smog.
As a non professional even I can imagine efficient setups to produce and refine algae for biofuel. Think towers of watertanks and refracting lightrods to grow algae underground. It could take up a large amount of land if farmed horizontally, but it doesn't have to.