Fortress Power Envy Duo 21 48V Hybrid Solar Inverter – 16kW High-Power Output for Home & Small Business
Fortress Power Envy Duo 21 48V Hybrid Solar Inverter – 16kW High-Power Output for Home & Small Business
Fortress Power Envy Duo 21 48V Hybrid Solar Inverter – 16kW High-Power Output for Home & Small Business
The Envy Duo 21 is Fortress Power’s most powerful 48V hybrid inverter, built to handle both residential and light commercial energy needs. With up to 25kW solar input and dual-phase support (240V split-phase and 208V three-phase), it delivers a reliable 12kW of continuous backup power with up to 16kW export capacity.
Perfectly paired with Fortress Power’s 48V batteries, the Envy Duo 21 offers flexible applications from whole-home backup to off-grid living. With built-in AC/DC breakers, rapid shutdown transmitter, and scalability up to 120kW, it’s a future-ready solution designed for maximum performance and long-term reliability.
Envy Duo 21 Installation Manual
| PV Output Data | |
| Number of MPPT | 3 |
| Inputs per MPPT | 2:2:1 |
| Max. usable input current (A) | 26/26/15 |
| Max. short circuit input current (A) | 31/31/19 |
| Start input voltage (V) | 100 |
| MPPT DC nominal voltage (V) | 360 |
| DC voltage range (V) | 100-550 |
| MPPt operating voltage range (V) | 120-440 |
| Max. Power (W) | 21000 |
| Max. PV ARRAY POWER (W) | 25000 |
| Backup Output Data | |
| Nominal output current (A) | 50@240V, 57.7@208V |
| Nominal output voltage (V) | (120/240), (120/208) |
| Continuous output power (VA) | 12000@240V, 12000@208V |
| Operating frequency (Hz) | 60 & 50 |
| Peak power (VA) | 2xPn, 0.5s |
| THDV | <3% |
| Switching Time (ms) | <20 |
| General Data | |
| Paralleling Capabiliy | Up to 10 units (120kW) |
| Dimensions | 22.3 x 35.2 x 11.2 in (566 x 893 x 285 mm) |
| Weight | 125.71 lbs (57 kg) |
| Degree of protection | NEMA4X / IP66 |
| Cooling concept | Smart Cooling Fans |
| Topology | High Frequency Transformer-less |
| Relative humidity | 0-100% |
| Altitude (m) | <6561ft. (<2000m) |
| Operating Temperature Range (ºC) | -25~60>40 Derating |
| Noise emission (dB) | <67 |
| Idle Consumption AVG (W) | 60 |
| Display | Touch color screen |
| Communication interface | Rs485/ Wi-Fi/ CAN |
| AC Grid Output Data | |
| Max. Output Current with pv (A) | 66.7 |
| Max. Output Power with pv (W) | 16000@240V 13800@208V |
| Continuous power output with battery only (W) | 12000@240V, 12000@208V |
| Rated voltage (V) | 120/240, 120/208 |
| Operating voltage range (V) | 180-270 |
| Operating frequency (Hz) | 50/60 |
| Operating frequency range (Hz) | 55-65 |
| Power Factor | 0.99@full load |
| Reactive power adjust range | -0.8~+0.8 leadingAdjustable |
| THDI | <3% |
| Sync inrush current (A) | 35 |
| Efficiency | |
| Max. EFFICIENCY PV to grid | 97.50% |
| Max. EFFICIENCY battery to grid | 94% |
| CEC Efficiency | 96.90% |
| Battery Data | |
| Type | Lithium battery/ No Battery |
| Max. charge current (A) | 250 |
| Max. discharge current (A) | 250 |
| Nominal voltage (V) | 48 |
| Voltage range (V) | 40-60 |
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Fortress Power Envy Duo 21 48V Hybrid Solar Inverter – 16kW High-Power Output for Home & Small Business
Fortress Power Envy Duo 21 48V Hybrid Solar Inverter – 16kW High-Power Output for Home & Small Business
The Envy Duo 21 is Fortress Power’s most powerful 48V hybrid inverter, built to handle both residential and light commercial energy needs. With up to 25kW solar input and dual-phase support (240V split-phase and 208V three-phase), it delivers a reliable 12kW of continuous backup power with up to 16kW export capacity.
Perfectly paired with Fortress Power’s 48V batteries, the Envy Duo 21 offers flexible applications from whole-home backup to off-grid living. With built-in AC/DC breakers, rapid shutdown transmitter, and scalability up to 120kW, it’s a future-ready solution designed for maximum performance and long-term reliability.
Envy Duo 21 Installation Manual
| PV Output Data | |
| Number of MPPT | 3 |
| Inputs per MPPT | 2:2:1 |
| Max. usable input current (A) | 26/26/15 |
| Max. short circuit input current (A) | 31/31/19 |
| Start input voltage (V) | 100 |
| MPPT DC nominal voltage (V) | 360 |
| DC voltage range (V) | 100-550 |
| MPPt operating voltage range (V) | 120-440 |
| Max. Power (W) | 21000 |
| Max. PV ARRAY POWER (W) | 25000 |
| Backup Output Data | |
| Nominal output current (A) | 50@240V, 57.7@208V |
| Nominal output voltage (V) | (120/240), (120/208) |
| Continuous output power (VA) | 12000@240V, 12000@208V |
| Operating frequency (Hz) | 60 & 50 |
| Peak power (VA) | 2xPn, 0.5s |
| THDV | <3% |
| Switching Time (ms) | <20 |
| General Data | |
| Paralleling Capabiliy | Up to 10 units (120kW) |
| Dimensions | 22.3 x 35.2 x 11.2 in (566 x 893 x 285 mm) |
| Weight | 125.71 lbs (57 kg) |
| Degree of protection | NEMA4X / IP66 |
| Cooling concept | Smart Cooling Fans |
| Topology | High Frequency Transformer-less |
| Relative humidity | 0-100% |
| Altitude (m) | <6561ft. (<2000m) |
| Operating Temperature Range (ºC) | -25~60>40 Derating |
| Noise emission (dB) | <67 |
| Idle Consumption AVG (W) | 60 |
| Display | Touch color screen |
| Communication interface | Rs485/ Wi-Fi/ CAN |
| AC Grid Output Data | |
| Max. Output Current with pv (A) | 66.7 |
| Max. Output Power with pv (W) | 16000@240V 13800@208V |
| Continuous power output with battery only (W) | 12000@240V, 12000@208V |
| Rated voltage (V) | 120/240, 120/208 |
| Operating voltage range (V) | 180-270 |
| Operating frequency (Hz) | 50/60 |
| Operating frequency range (Hz) | 55-65 |
| Power Factor | 0.99@full load |
| Reactive power adjust range | -0.8~+0.8 leadingAdjustable |
| THDI | <3% |
| Sync inrush current (A) | 35 |
| Efficiency | |
| Max. EFFICIENCY PV to grid | 97.50% |
| Max. EFFICIENCY battery to grid | 94% |
| CEC Efficiency | 96.90% |
| Battery Data | |
| Type | Lithium battery/ No Battery |
| Max. charge current (A) | 250 |
| Max. discharge current (A) | 250 |
| Nominal voltage (V) | 48 |
| Voltage range (V) | 40-60 |
Product Information
Product Information
Shipping & Returns
Shipping & Returns
Description
Fortress Power Envy Duo 21 48V Hybrid Solar Inverter – 16kW High-Power Output for Home & Small Business
The Envy Duo 21 is Fortress Power’s most powerful 48V hybrid inverter, built to handle both residential and light commercial energy needs. With up to 25kW solar input and dual-phase support (240V split-phase and 208V three-phase), it delivers a reliable 12kW of continuous backup power with up to 16kW export capacity.
Perfectly paired with Fortress Power’s 48V batteries, the Envy Duo 21 offers flexible applications from whole-home backup to off-grid living. With built-in AC/DC breakers, rapid shutdown transmitter, and scalability up to 120kW, it’s a future-ready solution designed for maximum performance and long-term reliability.
Envy Duo 21 Installation Manual
| PV Output Data | |
| Number of MPPT | 3 |
| Inputs per MPPT | 2:2:1 |
| Max. usable input current (A) | 26/26/15 |
| Max. short circuit input current (A) | 31/31/19 |
| Start input voltage (V) | 100 |
| MPPT DC nominal voltage (V) | 360 |
| DC voltage range (V) | 100-550 |
| MPPt operating voltage range (V) | 120-440 |
| Max. Power (W) | 21000 |
| Max. PV ARRAY POWER (W) | 25000 |
| Backup Output Data | |
| Nominal output current (A) | 50@240V, 57.7@208V |
| Nominal output voltage (V) | (120/240), (120/208) |
| Continuous output power (VA) | 12000@240V, 12000@208V |
| Operating frequency (Hz) | 60 & 50 |
| Peak power (VA) | 2xPn, 0.5s |
| THDV | <3% |
| Switching Time (ms) | <20 |
| General Data | |
| Paralleling Capabiliy | Up to 10 units (120kW) |
| Dimensions | 22.3 x 35.2 x 11.2 in (566 x 893 x 285 mm) |
| Weight | 125.71 lbs (57 kg) |
| Degree of protection | NEMA4X / IP66 |
| Cooling concept | Smart Cooling Fans |
| Topology | High Frequency Transformer-less |
| Relative humidity | 0-100% |
| Altitude (m) | <6561ft. (<2000m) |
| Operating Temperature Range (ºC) | -25~60>40 Derating |
| Noise emission (dB) | <67 |
| Idle Consumption AVG (W) | 60 |
| Display | Touch color screen |
| Communication interface | Rs485/ Wi-Fi/ CAN |
| AC Grid Output Data | |
| Max. Output Current with pv (A) | 66.7 |
| Max. Output Power with pv (W) | 16000@240V 13800@208V |
| Continuous power output with battery only (W) | 12000@240V, 12000@208V |
| Rated voltage (V) | 120/240, 120/208 |
| Operating voltage range (V) | 180-270 |
| Operating frequency (Hz) | 50/60 |
| Operating frequency range (Hz) | 55-65 |
| Power Factor | 0.99@full load |
| Reactive power adjust range | -0.8~+0.8 leadingAdjustable |
| THDI | <3% |
| Sync inrush current (A) | 35 |
| Efficiency | |
| Max. EFFICIENCY PV to grid | 97.50% |
| Max. EFFICIENCY battery to grid | 94% |
| CEC Efficiency | 96.90% |
| Battery Data | |
| Type | Lithium battery/ No Battery |
| Max. charge current (A) | 250 |
| Max. discharge current (A) | 250 |
| Nominal voltage (V) | 48 |
| Voltage range (V) | 40-60 |
