EG4 18kPV
For grid-tied homes that want whole-house backup and grid sell from one proven inverter. Compare against the FlexBOSS21 first, which costs less for more power.
Signature Solar $3,999.99 Shop Solar Kits $3,999.99$3,999.99
The EG4 18kPV is the better hybrid solar inverter overall, rated 4.3 to 4.1. The EG4 18kPV leads on value. The EG4 18kPV costs $999.01 less ($3,999.99 vs $4,999).
Sol-Ark 15K-2P
For homeowners and installers who want a long-proven whole-home hybrid with strong support. It costs more than EG4 for similar output.
Amazon Shop Solar Kits $4,999$4,999
Prices were last checked October 23, 2026 and are subject to change; the price and availability shown by the retailer at the time of purchase apply.
Which should you buy?
- Choose the EG4 18kPV for value ($333 per kW of continuous output vs $417 per kW of continuous output).
Scores side by side
Each factor is scored 0-100 against the same fixed reference points for every 120/240 V split-phase hybrid solar inverter; a clear win is highlighted. How we rank explains each one.
| Factor weight | EG4 18kPV | Sol-Ark 15K-2P |
|---|---|---|
| Overall rating | 4.3/5 | 4.1/5 |
| Value 30% | 73 $333 per kW of continuous output | 57 $417 per kW of continuous output |
| Solar input 20% | 75 18,000 W of panels, 600 V max, 3 MPPTs | 81 19,500 W of panels, 500 V max, 3 MPPTs |
| Efficiency 20% | 63 94% peak efficiency, 70 W idle | 52 90 W idle |
| Features 15% | 100 UL 1741 listed, Wi-Fi app, parallel stacking, grid sell-back, generator input, battery communication | 100 UL 1741 listed, Wi-Fi app, parallel stacking, grid sell-back, generator input, battery communication |
| Warranty 15% | 100 10-year warranty | 100 10-year warranty |
Specifications
| EG4 18kPV | Sol-Ark 15K-2P | |
|---|---|---|
| Output | ||
| Output voltage | 120/240 V split-phase | 120/240 V split-phase |
| Continuous output | 12,000 W | 12,000 W |
| Surge | 15,500 W | 24,000 W |
| Peak efficiency | 94% | - |
| Max efficiency | - | 97.5% |
| CEC efficiency | 96.9% | 96.5% |
| Idle draw | 70 W | 90 W |
| Transfer time | 20 ms | 5 ms |
| Parallel units | Up to 10 units | Up to 12 units |
| Solar | ||
| Max PV power | 18,000 W | 19,500 W |
| Max PV voltage (Voc) | 600 V | 500 V |
| MPPT range | 140 to 500 V | 150 to 425 V |
| MPPT trackers | 3 | 3 |
| PV current per tracker | 25 A | 26 A |
| Runs without battery | Yes | - |
| Battery and grid | ||
| Battery voltage | 48 V | 48 V |
| Battery types | Lithium, lead-acid | Lithium, lead-acid |
| Max charge current | 250 A | 275 A |
| Battery communication | Yes | Yes |
| Grid sell-back | Yes | Yes |
| Generator input | Yes | Yes |
| UL 1741 | UL 1741 SB | UL 1741 SB |
| Build | ||
| App monitoring | Included | Included |
| Enclosure | NEMA 4X | IP65 / NEMA 3R |
| Dimensions | 34.3 x 20.5 x 11.2 in | 33 x 19.4 x 12 in |
| Weight | 121 lb | 135 lb |
| Warranty | 10 years | 10 years |
| Released | 2023-05 | 2022-08 |