Project case study · Residential solar + storage
Dual GridBOSS + FlexBOSS Ground Mount
A 45.36 kW ground-mount design coordinating two independent EG4 power systems, 57.2 kWh of battery storage, whole-home backup, a standby generator, and long underground feeder runs.
The design challenge
Two PV-and-storage systems operating at one residence
The property required two hillside ground-mount arrays feeding two separate hybrid inverter and battery subsystems. Each subsystem needed its own protected DC and AC paths, microgrid interconnection device, backed-up loads, and coordinated relationship with the existing 120/240V service.
A 22 kW standby generator added another operating source. Long underground conduit runs from the arrays increased the importance of conductor sizing, routing, equipment locations, grounding, labeling, and a diagram that clearly explains normal, backup, and generator-fed operation.
Project identity and exact site details are withheld in the public sample.
Design response
Parallel architecture documented as a coordinated whole
Ground-mount PV
- 72 SEG Solar 630W modules total
- Two arrays of 36 modules each
- Long underground routes from array to equipment
Hybrid inverter systems
- Two EG4 FlexBOSS21 hybrid inverters
- Two EG4 GridBOSS interconnection devices
- Separate backed-up load centers coordinated
Battery and generator integration
- Four EG4 14.3 kWh PowerPro batteries
- 57.2 kWh combined storage capacity
- Generac Guardian 22 kW standby generator
Professional review package
- Project and site plans plus three-line diagrams
- Equipment data, certifications, and placards
- Plan set stamped by an Ohio professional engineer
What the plan set demonstrates
Backup capability requires explicit operating logic
A storage project is not fully communicated by listing batteries and an inverter. The drawings must show how sources, disconnects, backed-up loads, service equipment, and generator controls relate under different operating conditions. This set separates the two subsystems while showing how they coexist at the property.
The 21-page package also carries the design beyond the one-line concept. Site routing, equipment placement, conductor and protection details, placards, manufacturer requirements, battery certifications, and engineering review are assembled into one coordinated permit package.
Representative equipment
- SEG Solar SEG-630-BTZ-BG modules
- EG4 FlexBOSS21 hybrid inverters
- EG4 GridBOSS microgrid interconnection devices
- EG4 PowerPro batteries and Generac generator
Designing solar, storage, and generator backup?
Send the service, load, equipment, site, and backup requirements you have. Gemini Solar Design can organize the operating architecture and define the drawings needed for review.