There's a lot of research funding going into biofuels right now, but unfortunately the basic numbers don't make sense for biofuels as the world's primary energy source. You can convert solar energy into carbohydrates, extract the carbohydrates and convert them into ethanol, transport the ethanol to thousands of gas stations (sitting on prime commercial real estate), and combust it to create pressure that's harnessed to rotate an axle. There's a significant percentage of waste at each of those steps, and you end up requiring, like, all of the Earth's surface area for growing biofuel crops. (Even with algae.)

Alternately, you can harness sunlight directly, distribute it across the existing grid (fairly unobtrusively), temporarily store it in batteries or capacitors, and directly power an electric motor with it. Electric storage also benefits from the same economies of scale as laptops and cell phones.

My opinion, a humble one, is that biofuels are better suited for niche applications where electricity can't be used.