Just get enogh pannels, the inverter will get the voltage and the frequency you need. A 6000 BTU/hr AC good for 300 square feet will need 10 amps at 110 volts. A 10 amp solar panel will run about $8000 plus install. The panels will power the AC for about 2 hours per day, if you add about $1000 in batteries, you'll get 4 hours. If you want AC full time, the whole system will run %25,000. To buy the electricity it will cost about $1.5/day