EG4 FlexBOSS21 Split-Phase Hybrid Inverter, 21kW PV Input

The EG4 FlexBOSS21 is a split-phase, all-in-one hybrid inverter built for residential and small commercial off-grid and grid-tied systems. With a class-leading 21kW usable PV (DC) input, it delivers 12kW of continuous AC power even without sunlight and a full 16kW when solar production is available, while feeding through up to 90A of utility power at 120/240VAC. It's engineered as the enhanced sibling to EG4's flagship 18kPV inverter and is optimized to pair with EG4's GridBOSS MID (power gateway) — a combination that cuts installation costs and time by eliminating redundant components, making it a compelling choice for anyone building a powerful, scalable solar system.

Key Specs:

• PV Input: 21kW max usable, 24kW max input
• MPPTs: 3, configured as 26A/26A/15A — supports up to 5 strings, up to 13A panels, across up to 3 orientations
• On-Grid AC Output: 16kW continuous @ 240V, 13.8kW @ 208V
• Delivers 16kW to grid/loads with PV or battery; 12kW to loads/battery without PV
• Nominal AC Output Voltage: 120/240V | 120/208V | 240V
• Nominal Current: 50A
• Continuous Output Power: 12,000VA
• Starts a 5-ton AC unit easily
• Grid Feed-Through: up to 90A at 120/240VAC
• Dimensions: 30.4 x 22.3 x 11.2 in.
• Weight: 88 lbs.
• Warranty: 10 years

Scalable from 50 to 160 Amps (equivalent to full 200A service), the FlexBOSS21 is built to grow with your system. When paired with a GridBOSS, it adds AC coupling, smart loads, and generator support for a truly flexible off-grid or backup power setup.