Brought over from the AOC Video thread so as not to sidetrack that one..
Solar and wind-power, even taken together, will never be a 100% solution for all the reasons that people have said. Solar doesn't generate power at night and its efficiency and output drops off on cloudy days. Wind, although it is potentially capable of operating through 24 hours, doesn't generate power if there is no wind (or if there is too much wind).
Also, batteries are not yet available with sufficient energy density to store the solar and wind generated energy for use during those times of low or no output
To a certain extent these limitations could be mitigated by interlinking all of these power sources in a nationwide grid on the basis that there will always be plenty of sunshine and/or wind at multiple locations all over the grid. The down side is losses on the network; the longer the distances that power need to be transmitted, the more line losses you get. Those losses can be mitigated to a certain extent by having more and smaller energy generating plants closer together.
IMO, the only true solution to having an energy supply that does not rely on any fossil fuels is a combination of nuclear, hydro-electric, tidal, solar and wind power, with nuclear being the cornerstone. This is what could be called near-100% renewable solution. Only nuclear is not renewable, although as someone pointed out earlier, some advances are being made in extracting uranium from seawater.