Hey everyone! I'm currently working on my interconnection app with Consumers Energy here in Michigan. I've already received approval for all my drawings and tech specs, but they keep rejecting my application due to my response to a specific question about export capacity. The feedback I received was that 'Export capacity should be the aggregate max amount of continuous power that's possible to be exported to the distribution system, based on the bottleneck of the total AC and DC generating values. Use the lesser of the two values unless you're installing AC coupled batteries.' They also mentioned that if the inverter isn't power-limited, I should just use the total generator AC rating. My system features an EG4 Flexboss 21/Gridboss with 30 460 watt panels and 2 EG4 280 AH batteries. I initially used 16kW, the left over inverter output, but that was rejected. What do you all think?
1 Answer
It looks like the reason your value was rejected is that it’s actually the solar panel array that's the bottleneck, not the inverter. Based on your setup:
1. **Total DC Generating Value from Panels:** 30 panels at 460 watts each = 13,800 watts or 13.8 kW.
2. **Total AC Generating Value from Inverter:** Your EG4 Flexboss 21 can output 16 kW.
According to the rule - 'the lesser of the two values' - the correct export capacity is 13.8 kW since that's what your panels can provide. Your inverter has a higher capacity but it can only export as much as the panels are able to produce. Remember, the batteries won't change this number because they're linked directly to the inverter and not influencing the AC output directly.
By the way, dealing with Consumers Energy can be super frustrating during the application process!