Fortress Power Envy True 12kW 48V All-in-One Hybrid Inverter, 21kW Solar Input, 3 MPPT, 200A AC Passthrough, Built-In Rapid Shutdown, IP65, UL 1741

The Fortress Power Envy True 12kW is the flagship model in the Fortress Power inverter lineup. It is an all-in-one hybrid inverter that combines a solar inverter, 250A battery charger, and 200A transfer switch into a single NEMA 4X / IP65 enclosure. It delivers 12,000W of continuous split-phase 120/240Vac output and supports grid-tied, off-grid, and hybrid operation. Where the Envy 8kW and 10kW models are designed for essential load backup and smaller systems, the Envy True 12kW is built for whole-home coverage, including high-demand loads like central HVAC, electric ranges, EV chargers, and workshop equipment.

The defining feature of the Envy True 12kW is its 200A AC passthrough. Unlike the 8/10K models that use a backup panel approach, the True 12kW can sit between the meter and the main breaker panel, passing the full 200A service through to the entire home. When the grid goes down, the inverter takes over and powers the home from solar and batteries without requiring a separate critical loads subpanel. This simplifies system design and eliminates the need for homeowners to choose which circuits get backup power.

Solar Input

The Envy True 12kW has three independent MPPT channels. MPPT 1 accepts up to 12,000W with two string inputs, while MPPT 2 and MPPT 3 each accept up to 7,000W with one string input each, for a combined maximum PV input of 21,000W. The DC input voltage range spans 100-600Vdc, with a nominal input voltage of 360Vdc and a full power MPPT operating range of 230-500Vdc. Maximum DC input current is 25A on MPPT 1 and 15A each on MPPTs 2 and 3. Of the 21kW solar capacity, up to 18kW can be delivered simultaneously to the battery bank and AC outputs.

The three-MPPT design provides significant flexibility for array layout. Installers can place panels on multiple roof faces, at different tilts, or in partially shaded locations without the production loss that comes from mismatched strings on a shared MPPT. The larger MPPT 1 channel is well suited for a primary south-facing array, while MPPTs 2 and 3 can handle east/west arrays or secondary panel groups independently.

Grid and Generator Integration

The 200A AC passthrough allows the inverter to serve as the central hub for the entire home electrical system. When the grid is available, it passes up to 48,000W (200A at 240V) directly through to the main panel. The inverter can simultaneously charge the battery bank from the grid or from solar while household loads operate normally on grid power.

A dedicated auto-start generator port rated at 100A max (90A continuous) provides substantial generator integration. This is a significantly larger generator input than the 50A port on the Envy 8/10K models, making the True 12kW a better match for whole-home generator backup scenarios. The inverter can bring the generator online automatically based on battery SOC and manage the transition between grid, generator, solar, and battery power with seamless switching.

For grid-tied systems, the Envy True 12kW can export up to 12,000W at 240V back to the utility. It supports time-of-use optimization, peak shaving, and zero-export modes. Demand response integration is listed as a coming feature.

Battery Compatibility

The Envy True 12kW operates on a 48Vdc nominal battery bus with a voltage range of 48-56Vdc. It supports a maximum charge and discharge current of 250A and a maximum charge/discharge power of 12,000W. The inverter communicates with battery management systems through closed-loop protocols for real-time monitoring of voltage, current, temperature, and SOC (State of Charge).

The Envy True 12kW is compatible with Fortress Power's eVault MAX 18.5kWh, eFlex 5.4kWh, eFlex MAX 5.4kWh, and LFP-10 MAX battery systems.

Scalability

A single Envy True 12kW handles most whole-home scenarios, but the inverter supports parallel operation of up to 5 units for a combined output of 60kW. Three-phase compatibility is listed as an upcoming feature.

Built-In Safety and Code Compliance

The Envy True 12kW comes with a built-in APsmart Module Level Rapid Shutdown (RSD) transmitter and button, meeting NEC 690.12 requirements without additional external hardware. Integrated AC and DC breakers are built into the enclosure, reducing external disconnect requirements and installation time. The unit includes anti-islanding protection, SPD (surge protection device), AFCI (arc fault circuit interrupter), and ground fault monitoring.

Monitoring

The Fortress Power Guardian mobile app provides remote monitoring, system status, performance data, and firmware updates. Installers and homeowners can view real-time solar production, battery SOC, grid consumption, and inverter status from anywhere. The inverter communicates via RS485, Wi-Fi, and CAN interfaces. A color LCD screen on the unit provides local access to settings and system status.

Enclosure and Installation

The Envy True 12kW is NEMA 4X / IP65 rated for indoor or outdoor installation. The unit weighs 127 lbs (58 kg) and measures 31.1 x 20.5 x 10.4 inches (790 x 520 x 264 mm). The operating temperature range is -4°F to 140°F (-20°C to 60°C).

Output Quality

The Envy True 12kW produces a pure sine wave output at 120/240Vac split-phase. Maximum efficiency is rated at 97.5% (CEC weighted: 96.5%). The surge profile is tiered: 14kW for up to 10 minutes, 16kW for up to 5 minutes, and 20kW for 500ms. The sustained surge capability at 14kW for 10 minutes is particularly useful for systems with multiple motor loads that may start in sequence, such as HVAC compressors and well pumps.

Certifications

The Envy True 12kW is certified to UL 1741 and UL 1741 SB for grid-interactive safety, IEEE 1547A for interconnection standards, California Rule 21, FCC 15 Class B for EMC, and is approved for HECO, CEC, Luma, and ISO-NE programs.