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Fortress Power Whole Home Max 21KW Solar hybrid inverter - Envy 12 kW

Fortress Power Whole Home Max 21KW Solar hybrid inverter - Envy 12 kW

$5,364.27 USD
$ $5,364.27 USD
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9+ sold

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Unlimited lifetime support, always available.

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What is your return policy?

Returns are free in the first 30 days with no restocking or processing fees, although the customer may be responsible for paying return shipping. See our complete return policy on our Shipping, Delivery, and Returns page linked in the footer of this website.

What’s covered by your return policy?

Our returns policy covers all purchases made through Portlandia Electric Supply. For warranty issues, as authorized distributors, we honor the full manufacturer warranty of ALL the brands on our website. See our complete returns and warranty policies on our Shipping, Deliver, and Returns page.

How long will it take to receive my order?

All orders are processed within 72 hours and you can expect delivery on most orders within 5-7 business days. You will receive access to our customer portal after ordering, where it is easy to track all your shipments. See our Shipping, Delivery and Returns page for more details.

What are your financing and payment options?

We offer several ways to pay to make getting your solar kit simple:

Credit Card: if the purchase is greater than your card’s limit, you can split the cost onto multiple cards as well as Paypal, financing through Affirm, and ACH/bank transfer

You can arrange financing during the checkout process, or scroll further down this page for more details. Please note, if you'd like to finance your order, you can do so instantly, right at checkout.

How does your Lifetime Customer Support work?

Our legendary lifetime customer support has helped make us the #1 online solar retailer! We have a dedicated team of solar professionals standing by to help you navigate the world of solar with ease. From selecting the perfect solar kit to installation and beyond, we provide support and expertise at every step of the journey.If you need help with ordering, shipping, troubleshooting, expanding your system, warranty issues, or anything else you have questions about for as long as you own your Portlandia Electric Supply equipment, we’ve got you covered: we’re always only a phone call or email away.

Fortress Power Envy True 12 kW Hybrid Inverter — Whole-Home BackupAPsmart rapid-shutdown transmitter, installs are fast & code-friendly

The Fortress Power Whole Home Max 21KW Solar hybrid inverter - Envy 12 kW is a high-performance energy management solution designed to deliver reliable, intelligent, and uninterrupted power for modern homes. Built for whole-home backup and advanced solar integration, this inverter offers a seamless blend of efficiency, scalability, and safety, making it ideal for homeowners seeking energy independence and long-term savings.

As energy demands increase and grid reliability becomes less predictable, having a powerful solar hybrid inverter is no longer a luxury—it’s a necessity. The Fortress Power Whole Home Max 21KW Solar hybrid inverter - Envy 12 kW stands out with its robust engineering and future-ready design that supports both solar generation and battery storage.

Key features

  • 3 MPPT (max 21 kW PV input); 18 kW PV power delivered to battery & AC outputs
  • 12 kW backup @ 240 V; 10.4 kW @ 208 V; surge 20 kW (500 ms)
  • 200A AC passthrough for whole-home backup; seamless transfer (<20 ms)
  • NEMA 4X / IP65 outdoor-rated; color LCD; Wi-Fi/RS485/CAN monitoring
  • Built-in APsmart RSD transmitter; Tigo transmitters compatible (see manual)
  • Parallel up to 10 inverters; supports backup, off-grid, TOU, zero-export modes

Specifications

Envy 12 kW — specification box
PV input (DC)
MPPTs / strings 3 MPPT (2 / 1 / 1 strings)
Max PV input 21,000 W
Full-power MPPT window 230–500 V (100–600 V operating; 550 V max recommended)
Current limits 25 A / 15 A / 15 A (Isc 31 / 19 / 19 A)
AC (grid / passthrough)
Continuous to grid 12,000 W @ 240 V (10,400 W @ 208 V)
Max continuous current 50 A @ 240 V
Passthrough / GEN 200 A AC passthrough · 21,000 W GEN input
AC output (off-grid)
Rated output 12,000 W @ 240 V (10,400 W @ 208 V)
Surge 14 kW (10 min) · 16 kW (5 min) · 20 kW (500 ms)
Transfer time < 20 ms
Battery interface
Nominal voltage 48 V (40–60 V range)
Max charge/discharge 250 A · 12,000 W
Chemistry Lithium or lead-acid (closed/open loop)
Efficiency & protection
MPPT / max / CEC 99.9% / 97.5% / 96.5%
Ratings NEMA 4X · IP65 · AFCI · SPD · anti-islanding · DC switch
Rapid shutdown Built-in APsmart transmitter (SunSpec PLC); Tigo TX compatible
General
Dimensions (H × W × D) 34.2″ × 20.5″ × 11.2″
Weight ≈ 127 lb
Comms RS485 · Wi-Fi · CAN; app & remote monitoring
Certifications UL1741, UL1741SB, IEEE 1547A, Rule 21, ISO-NE, FCC15 class B, HECO, CEC, Luma
Warranty 10 years

Why Choose the Fortress Power Whole Home Max 21KW Solar Hybrid Inverter – Envy 12 kW?

The Fortress Power Whole Home Max 21KW Solar hybrid inverter - Envy 12 kW is engineered to support whole-home energy loads without compromise. With advanced hybrid functionality, it intelligently manages power from solar panels, batteries, and the utility grid to ensure maximum efficiency and reliability.

This inverter is designed for homeowners who want to reduce grid dependence while maintaining consistent power during outages. Its high power output allows it to run large appliances, HVAC systems, EV chargers, and other critical loads simultaneously—without interruption.

Key Performance and Power Capabilities

At its core, the Fortress Power Whole Home Max 21KW Solar hybrid inverter - Envy 12 kW delivers outstanding performance with a maximum output capacity of 21kW. This makes it suitable for large residential properties and energy-intensive households.

The integrated 200A transfer switch ensures smooth and automatic transitions during grid outages. When utility power is lost, the inverter switches seamlessly to battery and solar power, maintaining uninterrupted energy flow throughout the home.

Its hybrid design allows homeowners to utilize solar energy during the day, store excess power in batteries, and draw from those batteries during peak hours or outages—optimizing both savings and energy resilience.

Built-In Safety and Smart Technology

Safety and compliance are essential features of any modern solar inverter. The Fortress Power Whole Home Max 21KW Solar hybrid inverter - Envy 12 kW includes a built-in APsmart RSD transmitter, enabling rapid shutdown functionality to meet electrical safety standards.

This feature enhances protection for homeowners, installers, and first responders by ensuring that solar arrays can be quickly de-energized when required. The inverter also supports advanced monitoring capabilities, allowing users to track real-time energy production, consumption, and battery status through compatible monitoring platforms.

Flexible Installation and Scalability

Designed with flexibility in mind, the Fortress Power Whole Home Max 21KW Solar hybrid inverter - Envy 12 kW supports multiple system configurations. Whether paired with existing solar panels or installed as part of a new system, it integrates smoothly into various residential setups.

The inverter supports battery expansion, enabling homeowners to scale storage capacity as energy needs grow. This future-proof approach ensures long-term usability without requiring a complete system replacement.

Its compact yet durable construction allows for both indoor and outdoor installations, making it suitable for a wide range of environments.

Energy Independence and Cost Savings

One of the greatest advantages of the Fortress Power Whole Home Max 21KW Solar hybrid inverter - Envy 12 kW is its ability to promote true energy independence. By efficiently managing solar production and battery storage, homeowners can significantly reduce reliance on the grid.

The system enables load shifting, peak shaving, and optimized self-consumption—helping to lower electricity bills over time. During power outages, critical and non-critical loads remain operational, ensuring comfort and peace of mind.

Customer Reviews

Be the first to write a review
0%
(0)
0%
(0)
0%
(0)
0%
(0)
0%
(0)

What is your return policy?

Returns are free in the first 30 days with no restocking or processing fees, although the customer may be responsible for paying return shipping. See our complete return policy on our Shipping, Delivery, and Returns page linked in the footer of this website.

What’s covered by your return policy?

Our returns policy covers all purchases made through Portlandia Electric Supply. For warranty issues, as authorized distributors, we honor the full manufacturer warranty of ALL the brands on our website. See our complete returns and warranty policies on our Shipping, Deliver, and Returns page.

How long will it take to receive my order?

All orders are processed within 72 hours and you can expect delivery on most orders within 5-7 business days. You will receive access to our customer portal after ordering, where it is easy to track all your shipments. See our Shipping, Delivery and Returns page for more details.

What are your financing and payment options?

We offer several ways to pay to make getting your solar kit simple:

Credit Card: if the purchase is greater than your card’s limit, you can split the cost onto multiple cards as well as Paypal, financing through Affirm, and ACH/bank transfer

You can arrange financing during the checkout process, or scroll further down this page for more details. Please note, if you'd like to finance your order, you can do so instantly, right at checkout.

How does your Lifetime Customer Support work?

Our legendary lifetime customer support has helped make us the #1 online solar retailer! We have a dedicated team of solar professionals standing by to help you navigate the world of solar with ease. From selecting the perfect solar kit to installation and beyond, we provide support and expertise at every step of the journey.If you need help with ordering, shipping, troubleshooting, expanding your system, warranty issues, or anything else you have questions about for as long as you own your Portlandia Electric Supply equipment, we’ve got you covered: we’re always only a phone call or email away.

Fortress Power Envy True 12 kW Hybrid Inverter — Whole-Home BackupAPsmart rapid-shutdown transmitter, installs are fast & code-friendly

The Fortress Power Whole Home Max 21KW Solar hybrid inverter - Envy 12 kW is a high-performance energy management solution designed to deliver reliable, intelligent, and uninterrupted power for modern homes. Built for whole-home backup and advanced solar integration, this inverter offers a seamless blend of efficiency, scalability, and safety, making it ideal for homeowners seeking energy independence and long-term savings.

As energy demands increase and grid reliability becomes less predictable, having a powerful solar hybrid inverter is no longer a luxury—it’s a necessity. The Fortress Power Whole Home Max 21KW Solar hybrid inverter - Envy 12 kW stands out with its robust engineering and future-ready design that supports both solar generation and battery storage.

Key features

  • 3 MPPT (max 21 kW PV input); 18 kW PV power delivered to battery & AC outputs
  • 12 kW backup @ 240 V; 10.4 kW @ 208 V; surge 20 kW (500 ms)
  • 200A AC passthrough for whole-home backup; seamless transfer (<20 ms)
  • NEMA 4X / IP65 outdoor-rated; color LCD; Wi-Fi/RS485/CAN monitoring
  • Built-in APsmart RSD transmitter; Tigo transmitters compatible (see manual)
  • Parallel up to 10 inverters; supports backup, off-grid, TOU, zero-export modes

Specifications

Envy 12 kW — specification box
PV input (DC)
MPPTs / strings 3 MPPT (2 / 1 / 1 strings)
Max PV input 21,000 W
Full-power MPPT window 230–500 V (100–600 V operating; 550 V max recommended)
Current limits 25 A / 15 A / 15 A (Isc 31 / 19 / 19 A)
AC (grid / passthrough)
Continuous to grid 12,000 W @ 240 V (10,400 W @ 208 V)
Max continuous current 50 A @ 240 V
Passthrough / GEN 200 A AC passthrough · 21,000 W GEN input
AC output (off-grid)
Rated output 12,000 W @ 240 V (10,400 W @ 208 V)
Surge 14 kW (10 min) · 16 kW (5 min) · 20 kW (500 ms)
Transfer time < 20 ms
Battery interface
Nominal voltage 48 V (40–60 V range)
Max charge/discharge 250 A · 12,000 W
Chemistry Lithium or lead-acid (closed/open loop)
Efficiency & protection
MPPT / max / CEC 99.9% / 97.5% / 96.5%
Ratings NEMA 4X · IP65 · AFCI · SPD · anti-islanding · DC switch
Rapid shutdown Built-in APsmart transmitter (SunSpec PLC); Tigo TX compatible
General
Dimensions (H × W × D) 34.2″ × 20.5″ × 11.2″
Weight ≈ 127 lb
Comms RS485 · Wi-Fi · CAN; app & remote monitoring
Certifications UL1741, UL1741SB, IEEE 1547A, Rule 21, ISO-NE, FCC15 class B, HECO, CEC, Luma
Warranty 10 years

Why Choose the Fortress Power Whole Home Max 21KW Solar Hybrid Inverter – Envy 12 kW?

The Fortress Power Whole Home Max 21KW Solar hybrid inverter - Envy 12 kW is engineered to support whole-home energy loads without compromise. With advanced hybrid functionality, it intelligently manages power from solar panels, batteries, and the utility grid to ensure maximum efficiency and reliability.

This inverter is designed for homeowners who want to reduce grid dependence while maintaining consistent power during outages. Its high power output allows it to run large appliances, HVAC systems, EV chargers, and other critical loads simultaneously—without interruption.

Key Performance and Power Capabilities

At its core, the Fortress Power Whole Home Max 21KW Solar hybrid inverter - Envy 12 kW delivers outstanding performance with a maximum output capacity of 21kW. This makes it suitable for large residential properties and energy-intensive households.

The integrated 200A transfer switch ensures smooth and automatic transitions during grid outages. When utility power is lost, the inverter switches seamlessly to battery and solar power, maintaining uninterrupted energy flow throughout the home.

Its hybrid design allows homeowners to utilize solar energy during the day, store excess power in batteries, and draw from those batteries during peak hours or outages—optimizing both savings and energy resilience.

Built-In Safety and Smart Technology

Safety and compliance are essential features of any modern solar inverter. The Fortress Power Whole Home Max 21KW Solar hybrid inverter - Envy 12 kW includes a built-in APsmart RSD transmitter, enabling rapid shutdown functionality to meet electrical safety standards.

This feature enhances protection for homeowners, installers, and first responders by ensuring that solar arrays can be quickly de-energized when required. The inverter also supports advanced monitoring capabilities, allowing users to track real-time energy production, consumption, and battery status through compatible monitoring platforms.

Flexible Installation and Scalability

Designed with flexibility in mind, the Fortress Power Whole Home Max 21KW Solar hybrid inverter - Envy 12 kW supports multiple system configurations. Whether paired with existing solar panels or installed as part of a new system, it integrates smoothly into various residential setups.

The inverter supports battery expansion, enabling homeowners to scale storage capacity as energy needs grow. This future-proof approach ensures long-term usability without requiring a complete system replacement.

Its compact yet durable construction allows for both indoor and outdoor installations, making it suitable for a wide range of environments.

Energy Independence and Cost Savings

One of the greatest advantages of the Fortress Power Whole Home Max 21KW Solar hybrid inverter - Envy 12 kW is its ability to promote true energy independence. By efficiently managing solar production and battery storage, homeowners can significantly reduce reliance on the grid.

The system enables load shifting, peak shaving, and optimized self-consumption—helping to lower electricity bills over time. During power outages, critical and non-critical loads remain operational, ensuring comfort and peace of mind.
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From hurricanes to blackouts, reliable solar power ensures you're able to keep your home & family safe no matter what comes your way.

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Making one-click solar solutions simple since 2018. Whether you’re powering a cabin, charging devices, or backing up your home.

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Say goodbye to reliance on the energy companies. Enjoy the same freedom that 50,000+ customers have with their own solar power system.

Customer Success Stories

Troy P

EG4 off-grid base kit, Happy with my purchase.

This is the first stage of my three planned purches. I got the eg4 inverter 6000 XP base kit with six 400 watt panels and the two server rack batteries. Did a little online research and followed the instructions and it got set up without any issues. Right now I'm just running it in my garage on a single outlet and have been running dual 750 watt water distillers with it. Once I get the second inverter and a bunch more panels and batteries, I plan on attaching it to my subpanel in my house that has my lights and outlets and appliances on it. Then I'll get a soft start for my AC and blower and run it on my main panel.

Jacob B

Easy Process, Genuine Support

Trying to pick the correct solar system for your needs can be very technical and frustrating. I wanted to thank Yvhan and the Portlandia Electric supply team for their patience and helpful attitudes through multiple calls. I feel like we were able to narrow it down to what worked for me and my family. My system works great and I couldn't be happier to have picked Portlandia Electric Supply.

Patrick B

Off Grid Solar Purchase

I wanted to get an offgrid solar system for years but didn’t know where to start. I found Portlandia Electric Supply on Facebook and decided to submit a quote. Within 24 hours I had a custom proposal that was almost half the price of the companies I had previously got quotes from. My wife and I decided to order online and the kit came in a timely manner and it was an easy install. Great company to work with!

James Martin

Highly Recommend

I would like to take the time to express the outstanding service that I was provided with by Portlandia Electric Supply. They provided me with all the answers to my questions, and after reviewing our quote over the phone I felt comfortable proceeding to order my kit. It’s exactly what I needed and they were there to help us over the phone when we had questions installing it. I highly recommend others in need to choose Portlandia Electric Supply.

Brian H

Solar Kit for Mobile Work Van

As a professional videographer, I needed reliable power on the go.Portlandia Electric Supply Delta Pro and roof-mounted panels were the perfect solution. Setup was easy, and the kit included everything needed. The Delta Pro powers my cameras, lights, laptop, and a small fridge with impressive battery capacity.

Keith S

Best Tech Support

You folks have been wonderful guiding me through the ins and outs of going solar. Plus your tech guys Rod and Nelson are the absolute best. They explained all the different aspects of inverters, batteries and how to keep them in top condition. Too much more to put here… but no other company has the 100% tech support you provide for your customers!

Coll A

Great Experience

My experience with Portlandia Electric Supply has been excellent. Before the sales, they answered all my questions to assure that I got what I needed. After the sales they continued to support me with answers and help. I had a warranty issue with a unit, and it was handled as well as possible. I would recommend them to anyone looking to go solar.

Troy P

EG4 off-grid base kit, Happy with my purchase.

This is the first stage of my three planned purches. I got the eg4 inverter 6000 XP base kit with six 400 watt panels and the two server rack batteries. Did a little online research and followed the instructions and it got set up without any issues. Right now I'm just running it in my garage on a single outlet and have been running dual 750 watt water distillers with it. Once I get the second inverter and a bunch more panels and batteries, I plan on attaching it to my subpanel in my house that has my lights and outlets and appliances on it. Then I'll get a soft start for my AC and blower and run it on my main panel.

Jacob B

Easy Process, Genuine Support

Trying to pick the correct solar system for your needs can be very technical and frustrating. I wanted to thank Yvhan and the Portlandia Electric supply team for their patience and helpful attitudes through multiple calls. I feel like we were able to narrow it down to what worked for me and my family. My system works great and I couldn't be happier to have picked Portlandia Electric Supply.

Patrick B

Off Grid Solar Purchase

I wanted to get an offgrid solar system for years but didn’t know where to start. I found Portlandia Electric Supply on Facebook and decided to submit a quote. Within 24 hours I had a custom proposal that was almost half the price of the companies I had previously got quotes from. My wife and I decided to order online and the kit came in a timely manner and it was an easy install. Great company to work with!

James Martin

Highly Recommend

I would like to take the time to express the outstanding service that I was provided with by Portlandia Electric Supply. They provided me with all the answers to my questions, and after reviewing our quote over the phone I felt comfortable proceeding to order my kit. It’s exactly what I needed and they were there to help us over the phone when we had questions installing it. I highly recommend others in need to choose Portlandia Electric Supply.

Brian H

Solar Kit for Mobile Work Van

As a professional videographer, I needed reliable power on the go.Portlandia Electric Supply Delta Pro and roof-mounted panels were the perfect solution. Setup was easy, and the kit included everything needed. The Delta Pro powers my cameras, lights, laptop, and a small fridge with impressive battery capacity.

Keith S

Best Tech Support

You folks have been wonderful guiding me through the ins and outs of going solar. Plus your tech guys Rod and Nelson are the absolute best. They explained all the different aspects of inverters, batteries and how to keep them in top condition. Too much more to put here… but no other company has the 100% tech support you provide for your customers!

Coll A

Great Experience

My experience with Portlandia Electric Supply has been excellent. Before the sales, they answered all my questions to assure that I got what I needed. After the sales they continued to support me with answers and help. I had a warranty issue with a unit, and it was handled as well as possible. I would recommend them to anyone looking to go solar.

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Trusted Company, Real Products, Lifetime Support

Avoid Scams, Buy with Confidence, Enjoy Peace of Mind

Manufacturer Warranty, Exceptional Service

Shop Securely, Trusted Supplier, 100% Satisfaction

Trusted Company, Real Products, Lifetime Support

Avoid Scams, Buy with Confidence, Enjoy Peace of Mind

Manufacturer Warranty, Exceptional Service

Shop Securely, Trusted Supplier, 100% Satisfaction

Trusted Company, Real Products, Lifetime Support

Avoid Scams, Buy with Confidence, Enjoy Peace of Mind

Manufacturer Warranty, Exceptional Service

Shop Securely, Trusted Supplier, 100% Satisfaction

Trusted Company, Real Products, Lifetime Support

Avoid Scams, Buy with Confidence, Enjoy Peace of Mind

Manufacturer Warranty, Exceptional Service

Shop Securely, Trusted Supplier, 100% Satisfaction

Trusted Company, Real Products, Lifetime Support

Avoid Scams, Buy with Confidence, Enjoy Peace of Mind

Manufacturer Warranty, Exceptional Service

Shop Securely, Trusted Supplier, 100% Satisfaction

Trusted Company, Real Products, Lifetime Support

Avoid Scams, Buy with Confidence, Enjoy Peace of Mind

Manufacturer Warranty, Exceptional Service

Shop Securely, Trusted Supplier, 100% Satisfaction

Trusted Company, Real Products, Lifetime Support

Avoid Scams, Buy with Confidence, Enjoy Peace of Mind

Manufacturer Warranty, Exceptional Service

Shop Securely, Trusted Supplier, 100% Satisfaction

Trusted Company, Real Products, Lifetime Support

Avoid Scams, Buy with Confidence, Enjoy Peace of Mind

Manufacturer Warranty, Exceptional Service

Shop Securely, Trusted Supplier, 100% Satisfaction

Trusted Company, Real Products, Lifetime Support

Avoid Scams, Buy with Confidence, Enjoy Peace of Mind

Manufacturer Warranty, Exceptional Service

Shop Securely, Trusted Supplier, 100% Satisfaction

Trusted Company, Real Products, Lifetime Support

Avoid Scams, Buy with Confidence, Enjoy Peace of Mind

Manufacturer Warranty, Exceptional Service

Be Smart, Buy From an Authorized Dealer

When you choose Portlandia Electric Supply, you’re buying real products from a trusted company with established supplier relationships. Enjoy peace of mind with 100% manufacturer warranty coverage and lifetime customer support. In an age where online shopping is fraught with risks, it’s crucial to avoid fly-by-night websites that skirt regulations. Shop with confidence, knowing you’re getting genuine quality and reliable service.

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