Everything Solar Forum

Hello

I want to replace my 18 year old  rooftop PV system on my house. A few weeks ago I posted here asking for opinions of residential inverter brands especially with battery attached. I have evaluated both SMA Sunny Boy and Solar Edge HD Wave Hub with batteries in my inverter testing  lab at University Delaware but they are 2021 vintage.  I had a few responses with two recommending Solar Edge. My installer wants to install SE for me as well But nationally, over 50% of residential systems use Enphase Microinverters. In my state (Delaware) Enphase is about 70% of residential. Does anyone have informed knowledgeable perspective of the new Enphase micros with their battery package? It has to be AC coupled since they immediately convert to AC on the roof while SE is DC coupled. Any experience with installation, operation, customer portal interface  of the Enphase with storage? Or the recent SE Energy Hub with storage? 

Thank you!

Steve Hegedus

University of Delaware 

I myself like pure string inverters, location sun dynamics permitting. It is the cheapest and most efficient system. Nothing on the roof except the panels. 20 panels, 20 possible points, not 40.

DC into the string inverter and config the batteries how you want them. Most installers go with what they are familiar with, use allot of and get the best cost breaks, bigger profit for them, etc.. Speaks to Solar edge and Enphase.

Don't forget rapid shutdown switches, which would increase your 40 points to 60? A failed dumb rapid shutdown switch in an array can be harder to notice, or find, than a properly mapped optimizer or microinverter system, plus the added module-level monitoring is a big plus in many situations.

That's great that you are still in production after that long. Kudos. Upgrading equipment, much like software can become a chain reaction on the entire system. 

Hi David

The reason I am retiring my 18 y/o system is because of a convergence of 4 things: I want to replace my 20 year old roof before it leaks; I have to remove the old modules to replace the roof; with new modules and power optimizers, I will be able to install almost 4 times more power on the roof by taking advantage of partially shaded areas and more efficient modules; and the 30% tax incentive will start to decrease next year. So put them all together and it makes sense to do it now. The old system has degraded very much as expected, about 0.5% per year so it is still making about 90% of the original power. 

Thanks for sharing about your experience with Chiilcon microinverters. Never heard of them. 

Steve 

I have installed both SolarEdge and EnPhase.  For us the wiring is slightly easier with SolarEdge on the roof with their optimizers.  I also like their DC coupled battery as it is about 10% more efficient as you skip an AC to DC conversion.  BUT I like EnPhase support better.  Performance wise the two are VERY similar.  So I would look at what your local installer prefers and what price they will give you.  The few times I checked SolarEdge was slightly better on pricing as well but the differences are not large.

My own personal taste leans towards KISS. A simple string inverter with only panels on the roof (Hardly ever fail) leaves everything that can go wrong on the ground. No ladders or roof. Fewer failure points. The longest I ever waited for a string inverter replacement was 10 days. 

As long as the sun access is clean East to West, I will take string any day.