Fortress Power Envy Duo 21 Hybrid Inverter - 48V/12000W

The Fortress Power Envy Duo 21 is a powerful 48V hybrid inverter designed to handle demanding residential and light commercial energy needs. With a maximum PV input of 25kW and dual-phase compatibility (240V split-phase and 208V three-phase), it delivers 12kW of continuous backup output power across both configurations, with max export power of 16kW.

Perfectly matched with Fortress Power’s 48V battery systems, the Envy Duo 21 supports multiple applications. Its integrated AC/DC breakers, rapid shutdown transmitter, and parallel scalability up to 120kW make it a versatile, future-ready solution.

Features

High PV Input Capacity

Accepts up to 25kW of PV input—ideal for large residential or light commercial solar arrays seeking maximum generation potential.

Dual Voltage Compatibility

Supports both 240V split-phase and 208V three-phase* applications, making it flexible for a wide range of grid configurations.

Seamless Battery Integration

Pairs with Fortress Power 48V batteries to deliver 12kW of continuous power and up to 16kW peak, ensuring stable, whole-home or light commercial backup.

Scalable System Design

Parallel up to 10 units for a total output of 120kW, expanding as energy demands grow without the need for complete system redesign

Integrated Install-Friendly Hardware

Includes built-in AC/DC breakers and an integrated rapid shutdown transmitter for faster, code-compliant installations.

Remote Monitoring and Firmware Updates

Monitor your solar production, battery performance, and grid consumption anytime via the Fortress Power mobile app. The Envy also supports remote firmware updates, ensuring your system stays up to date without the need for onsite visits.