RE China building 2x as much Solar as Rest of the World Combined. Just Observing the cost of the Solar Cells would be much cheaper than countries they exported

RE China building 2x as much Solar as Rest of the World Combined. Just Observing the cost of the Solar Cells would be much cheaper than countries they exported too. Having another source of energy is good idea , in case they can not obtain coal ( from overseas ) for whatever reason. China is also rapidly increasing nuclear power stations . China has 50 nuclear power stations and are currently building another 23. The problem with Solar and wind is storing it for the inevitable combined solar and wind droughts that occur every several years. Their is also the possible "transmission problem" in such a (no solar/wind for several days) situation. Their needs to be the transmission capacity to get the electricity from where its stored (in batteries OR hydro storage ) to where the solar/wind drought is happening.