Growatt SPH 10000TL-HU-US
For grid-tied homes that want solar, battery backup and export in one outdoor box at a lower price than Sol-Ark or Fortress.
Amazon$2,599
4.4/5
For grid-tied homes that want whole-house backup and a big solar array from one inverter. It gives more output than the 18kPV for less money.
- 12 kWOutput
- 48 VBattery
- 21,000 WSolar input
- 65 WIdle draw
- 10 yearsWarranty
Check price at Signature Solar$3,599.99
Price checked October 23, 2026. As an Amazon Associate we earn from qualifying purchases.
Pros
- 16 kW with solar and grid (12 kW from battery) covers large homes from one unit
- Three trackers take about 21 kW of panels across several roof faces
- Grid sell with UL 1741 SB, in an outdoor NEMA 4X case
- Ten-year warranty, with Wi-Fi in the box
Cons
- About 65 W idle draw
- At 121 lb it needs two installers
- Generator hookup isn’t covered on the spec sheet
The EG4 FlexBOSS family
Every EG4 FlexBOSS model we rank, smallest first. Ratings compare each against its own output.
| Model | Output | Rating | Price |
|---|---|---|---|
| EG4 FlexBOSS18 | 10 kW | 4.4/5 | $3,199.99 |
| EG4 FlexBOSS21 (this one) | 12 kW | 4.4/5 | $3,599.99 |
How it scores
The rating comes from 5 measured or published factors, each scored 0-100 against fixed reference points for its output. How we rank explains each one.
Specifications
| Model number | IV-16000-HYB-AW-FX-XX |
|---|---|
| Output | |
| Output voltage | 120/240 V split-phase |
| Continuous output | 12,000 W |
| Surge | 24,000 W |
| Peak efficiency | 94% |
| CEC efficiency | 97% |
| Idle draw | 65 W |
| Transfer time | 20 ms |
| Parallel units | Up to 16 units |
| Solar | |
| Max PV power | 21,000 W |
| Max PV voltage (Voc) | 600 V |
| MPPT range | 120 to 440 V |
| MPPT trackers | 3 |
| PV current per tracker | 26 A |
| Battery and grid | |
| Battery voltage | 48 V |
| Max charge current | 250 A |
| Battery communication | Yes |
| Grid sell-back | Yes |
| UL 1741 | UL 1741 SB |
| Build | |
| App monitoring | Included |
| Enclosure | NEMA 4X |
| Dimensions | 30.43 x 22.28 x 11.22 in |
| Weight | 121 lb |
| Warranty | 10 years |
| Released | 2024-11 |
Alternatives in this output
EG4 FlexBOSS18
For grid-tied homes that want net metering and whole-home backup at a lower price than the FlexBOSS21. Choose the 21 if you need more battery-only output or a third tracker.
Signature Solar $3,199.99$3,199.99
Fortress Power Envy Duo 21
For homes with a large roof array that want whole-house backup and grid export from one outdoor unit. It takes more solar than the Envy True 12 for the same price.
Wind & Sun $4,898$4,898
Compare
Compare the EG4 FlexBOSS21 with any other hybrid solar inverter →
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