When designing solar panel systems for homes how do you convert the watts generated by the 12V DC solar panels to watts available in a 110/120V AC system? When I do the math it seems to defy logic.
Watts = amps * volts (which also means W/V=A) is the basic formula. So what is wrong with the following: The solar system generates 100 watts at 12V DC = 8.33 amps. Now I want to use that power that has been generated so I feed the power into a 12V DC to 110V AC inverter. When I multiply the amps produced of 8.33A by 110V I get 916.3 watts. I always thought that a watt was a watt (minus power loss due to resistance and inefficiencies of your circuit design of course) so do I really turn 100 watts DC into 900 watts AC? That seems to defy logic. Or do I still have only have 100W 110V AC and why? Am I overlooking a formula that should be included when Inverting DC to AC?
If my math is right then why do they say that I would need a 5kW 12V DC system for my home? That would convert to 416 amps and a 45.8kW 110V service in my home when the solar is at peak performance. (I know that I would get no power at night). My average hourly usage is 2kWh so it seems that 46kW is WAY overkill even if I save some to batteries for night time use.