Solar energy does not have the power to combust, which is highly required in a modernized world. New technology, such as micro algae production, will solve problems associated with other forms of biofuel, such as more land needed for fuel production, food costs, etc. Solar power is not available all the time either, while algae doesn't need sun all the time, unlike most forms of modern equipment that utilize solar power which usually can't survive that long. Biofuels are carbon neutral too, meaning whatever carbon released will be absorbed again by the next crop that will be grown to replace it. As you can see, solar power is a good resource, but biofuel is pretty much superior to solar power.
Solar energy doesn't require the burning of any fuels whatsoever. Biofuels don't burn as much carbon as unleaded gas, but they still give off carbon monoxide into the atmosphere. Solar power can be used to fuel completely electric vehicles that give off no emissions at all. Give it 20 years and a large percentage of American cars will run on electricity powered by wind and solar as opposed to coal-burning plants and unleaded gasoline.
The sun is the biggest source of energy that we can even comprehend from our planet. If we do not seek to utilize its free and infinite power than we are passing up on a great opportunity. Solar panels, while not perfect, can become an ideal and future to unlimited energy production. Algae biofuel is still bioeful, still processed, and still harmful.