The debate over renewable energy versus fossil fuel is really one more about time span. Fossil fuels work just as well, if not better, than renewable energy sources however they are limited in supply. Once fossil fuels run out, there will be no new sources for thousands of years. This is not a problem if you are thinking for the here and now, but if future generations, or even a few decades, is the time frame considered, the problem becomes considerably more applicable.
Currently, technology is adapted to fossil fuels making them readily available high energy sources with the ability to go from source to the user. In this way, the practicality of fossil fuels requires little to no changes in our current thinking or lifestyle. Though pollution is created in their use, the pollution factor doesn't directly effect the next 5 to 10 years much.
Renewable energy, requires a much longer time frame view. Though the technology surrounding renewable energy is not as advanced as for fossil fuels, it is rapidly getting there. The cost difference is diminishing dramatically as more efficient methods and infrastructure are put into place. Secondly, renewable energy never runs out and does not further the environmental damage of fossil fuels.