Hey everyone, I'm diving into setting up a rooftop solar system and I'm considering using a Sol-Ark 15K inverter to power my entire grid-connected house. I really want to have backup generator support since I've heard that micro-inverters generally don't work well with generators and most string inverters don't offer that feature either. However, I'm facing a challenge with limited roof space, as I can only fit about 10kW of solar panels up there.
I've been using an online design tool, and it's flagging that my DC/AC ratio is too low since I have more inverter capacity than what I need with the panel installation. If I opt for a smaller Sol-Ark inverter, I'll end up with a maximum output current of 66A, while the 15kW model can handle 200A through the grid.
My main concerns are whether oversizing the inverter could lead to reduced efficiency or shorten its lifespan, or if it's just an unnecessary cost. Or are there better options for combining solar panels and generators that I might have overlooked?
3 Answers
I'm currently wiring a 10kW solar setup into the same 15k inverter for a similar reason! I feel like that warning about the ratio is more of a heads-up than anything. Since I’m using just three out of the four MPPT inputs, we’re probably on a good path. Oh, and by the way, Enphase systems do support backup generators if you want to consider that!
A lot of folks choose the 15k inverter mainly for that 200A passthrough, it’s definitely a popular option. In terms of efficiency, while an oversized inverter can lead to some inefficiencies, it generally won’t drastically shorten the lifespan, so you should be alright! Go for it if the higher amps are what you need!
Definitely take a close look at the inverter’s specs! The 15k can handle a big 200A passthrough, but keep in mind it only handles 62.5A itself. For most loads, that’s still pretty capable. I managed to cover about 80% of my needs with a smaller inverter setup, steering clear of high-load appliances like dryers and ovens on solar. Also, the EG4 inverters are great and they work well with generators!