On your explanation of enphase sizing tool, I also am an existing enphase customer whom was looking to add battery back up and found the existing customer sizing tool to be useless. When attempting to work through the issue with enphase I had a ticket issued to me so I could work with them to resolve the sizing g tool issues. After three weeks I gave up. BTW I am impressed with my enphase array 3 yr running now. Also I have purchased a bess from a different company partially due to enphases lack of follow up with my battert sizing tool issue.
I strongly recommend you take a look at the hybrid inverters and what they bring to the table today. I recently installed the Solark 15 K on my own home and as a single solution to all of the challenges that in phase brings to your installation, The other term your using his auto transformer where you mean auto transfer switch. Take a look at the EG for rackmount battery. 48 V agnostic batteries are an excellent source of storage and use. Has these hybrid systems become more available I expect you’ll see systems like in phase or solar edge, the less popular.
Hey Daniel - one of the problems we have in the PV industry (in that it is very new and always changing) is standardization of language. I have seen the term auto transformer, auto transfer switch, smart switch - all used interchangeably. One is probably better than the others, but it hasn't settled in my mind. The Sol-Ark is a good system (I have installed them as well). Again, we use the term hybrid inverter in many ways. All three systems you mention (Enphase, SolarEdge and Sol-Ark) can be configured into hybrid systems. I think the advantage of the Sol-Ark system is that it can be a true off-grid system as well. Of course it always comes down to price and what the owner wants from the system - which is why there isn't just one dominant player in the industry.
Again good discussion. I especially liked the prediction of the bi-directional grid, energy exchange medium and internet analogy. It's hard to design one size fits all storage given site specifics, occupant lifestyles and utility tariffs. However, after completing a number of resiliency systems operating 4 seasons, focused on self-consumption plus energy and power demand arbitrage, I find 2X the DC array a sweet spot for storage. For example, with a DC 10 kW array then attach 20 kWh storage. This with the perspective and alternative view that the grid can be a lucrative opportunity - grid backup to an alternative energy system is a bonus. And to note, having Installed a number of Enphase systems, ROI on the load controller is poor. They only function off-grid. So if grid tied, consider 3rd party management useable 24/7 and 365 on or off grid for the best ROI. Also note you can call Enphase and now request auto firmware pushes be blocked, leaving a happy system and owner happy. Keep up the good work
