Power One Aurora series inverters

Re: Power One Aurora series inverters

I think you are on the right track. The Aurora is a leading brand in this size. For a smaller system I currently use SMA's new TL inverters, but the largest they go right now is 5kW. The Aurora is made here in Arizona, has dual inputs so is much more flexible on string sizes which you will need for adding on more PV. You need to plan that out - it is easy to paint yourself into a corner and have to compromise when adding. Choose panels that are common and going to be around in a couple years. Probably need to do two shorter strings and then lengthen them rather than add a third string. Think about how your are going to do the array wiring as well. Should be able to add panels without having to reinstall the 1st ones in order to rewire. If the panels leads are long enough, you can do something called skip wiring and have a lot more flexibility in the wiring . These inverters can handle mismatched inputs though - each input can handle up to 2/3 the full rating of the inverter.
An inverter normally runs partially loaded, rarely does it run full up because that only happens with the sun straight on at a good angle on a clear, cool day. Most of its operating time is done at 1/2 power or less. In fact, it is common practice to run arrays stc rated 10 to 20% higher than the inverter. Fixed arrays spend so few hours at their max ratings that it is not quite worth the extra inverter size. On a 5kw inverter, you can put a 6kW array no problem. Then you could choose a SMA SB5000TL and get its unique Emergency Outage feature that no one else has. It also is transformerless with dual inputs, and great efficiency specs.