So, how do we build solar faster? The energy is there, there is ~89 petawatts of incoming solar hitting the ground and we apparently use ~18 terawatts and it looks technically achievable using current technology, so the main restriction would seem to be production capacity and capital costs.
We'd have to cover too much land with solar panels. What we need are more nuclear power plants, but no one will build them anymore.
[1] 100 TW primary energy, 100 W/m^2 for solar irradiation on earth and 20% efficiency of the solar cells. Then you need 5e6 m^2.
[2] http://www.bloomberg.com/news/2010-04-22/windmill-boom-curbs...