MarkSolar
Solar Enthusiast
I currently have a 7.7kW Fronius Primo inverter grid tied that's 3 years old. I want to approximately double my system to 15kW. Can't decide if I should replace existing inverter with a single ~15kW inverter, or buy a second inverter like the 7.7kW one I have. I'm combining my three strings, so I only use/need one MPPT. If I buy a 15kW inverter, I'm not sure I could configure things to stay within the MPP voltage range and max current, and haven't worked out the details yet. The current location of my inverter is too crowded to add another inverter immediately next to it, so it would require a modest amount of running conduit to add a second inverter location, but no big deal. So one inverter would make the layout tidier. I like the idea of having a second inverter in case one system breaks for whatever reason. But two devices have a higher probability of a failure than one device. I already paid $1600 for the inverter I have and it's not very old. I would have to spend about $2000 to get a second one at today's prices, while a 15kW inverter would be about $4K assuming I stick with Fronius. I'm still in the spit balling phase of the project, so any thoughts are appreciated.
