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Fortress PowerSolar Inverters
Fortress Power 21kW Three Phase Hybrid Inverter + Guardian Dongle
MPN Envy Duo 21In stock
Envy Duo 21 · 21000 W · Hybrid · 125.7 lb (57 kg)
521Power output
21000 W
Price per watt
$0.23/W
Ships as
Box
Available
5 units
Volume pricing
MOQ based ranges| Quantity | Price per item | Request a quote |
|---|---|---|
| 1 unit | $4,898.00 | |
| 2 - 3 units | On request | |
| 4+ units | On request |
Volume ranges are MOQ based. Prices above the first tier are confirmed on a quote.
Fortress Power 21kW Three Phase Hybrid Inverter + Guardian Dongle price history
Fortress Power 21kW Three Phase Hybrid Inverter + Guardian Dongle pricing on Sunhub is $4,898 ($0.23/W) per unit.
Fortress Power 21kW Three Phase Hybrid Inverter + Guardian Dongle price data
- Price per watt (current)
- $0.23/W
- Lowest price, last 12 months
- $4,898
- Average price, last 3 months
- $4,898
- Price changes, last 12 months
- 0
Buying in volume? Request a volume quote.
Overview
Fortress Power 21kW Three Phase Hybrid Inverter + Guardian Dongle HIGH-CAPACITY HYBRID INVERTER ENGINEERED FOR LARGER SOLAR + STORAGE SYSTEMS Guardian Dongle: Real-time inverter monitoring, remote firmware updates, and live technical support—fully compatible with Envy 8k, 12k, and Duo 21. WiFi connectivity included.
Key Features
Accepts up to 25kW of PV input—ideal for large residential or small commercial solar arrays seeking maximum generation potential. Supports both 240V split-phase and 208V three-phase applications Parallel up to 10 units for a total output of 120kW, Includes built-in AC/DC breakers and an integrated rapid shutdown transmitter for faster, code-compliant installations.
12 kW (50A @240V) Backup Power
Product Details
- Manufacturer Part Number
- Envy Duo 21 Max Output
- Power
- 21 kW Rated Input
- Voltage
- 120/240 | 120/208 Vac Rated
- Current
- 50@240V, 57.7@208V
- Dimensions
- 35.2 x 22.3 x 11.2 in
- Weight
- 125.7 lbs
Documents
Specifications
| Brand | Fortress Power |
|---|---|
| Category | Solar Inverters |
| MPN | Envy Duo 21 |
| Wattage | 21000 W |
| Weight | 125.7 lb |
| Shipping format | Box |
| Ships from | Commerce, CA |
| Warranty | 10 Years |
| Incoterms | EXW - Ex Works (Place) |
| Grid voltage | 120/240/208 |
| Power output | 21 |
| Payment terms | To Be Decided |
| Output current | 50 |
| Delivery schedule | To Be Decided |
Shipping & returns
Shipping terms
Ex Works (pickup). Ex Works: Commerce, CA. Delivery is quoted separately.
Freight
Ships by box via LTL or full-truckload freight from Commerce, CA. Freight is quoted from your ZIP, pallet count, and dock or liftgate needs.
Returns & buyer protection
Covered by Sunhub Buyer Protection: items arrive as described or your money back. Manufacturer warranty claims are handled directly with the brand.
Seller & buyer protection
SU
Sunhub MarketplaceVerified seller
Every supplier on Sunhub is vetted before listing. Orders are held under Sunhub Buyer Protection until the equipment arrives as described, and payment is only released once you confirm receipt.
Buyer protectionSecure checkoutShips by box
Questions & answers
- What is the minimum order for Fortress Power 21kW Three Phase Hybrid Inverter + Guardian Dongle?
- Orders start at 1 box. 5 units are currently available.
- How is Fortress Power 21kW Three Phase Hybrid Inverter + Guardian Dongle packed and shipped?
- It ships by box from Commerce, CA. Freight moves LTL or full truckload depending on volume.
- Is freight included in the price?
- No. Ex Works (pickup): Ex Works: Commerce, CA. Delivery is quoted separately. Send your delivery ZIP, pallet count and dock or liftgate needs and we quote freight separately.
- Is there volume pricing?
- Yes. Pricing steps down by quantity, from 1 unit at $4,898.00 per box to 4+ units on quote. Larger volumes are quoted directly.
- What lead time should I expect?
- Stocked units typically release within 1-3 business days of a cleared payment, plus transit time from Commerce, CA.
- What warranty and buyer protection apply?
- All stock is sold new with the manufacturer warranty, handled directly with the brand. Every Sunhub order is covered by Buyer Protection: equipment arrives as described or you get your money back.
Buyer reviews
No buyer reviews yet for this product. Sunhub only publishes reviews from verified, completed orders, so nothing is shown until this part has shipped through the marketplace.
Need references before you commit? Post a request and our sourcing team shares comparable projects, supplier history and lead-time performance for this category.
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