Sol-Ark 18K-2P
For large homes that want seamless whole-house backup with no load shedding. Few inverters match its output, but it costs well over most rivals.
Shop Solar Kits $6,298$6,298
The Sol-Ark 18K-2P and the Sol-Ark 15K-2P are evenly matched, rated 4.1 and 4.1. The Sol-Ark 18K-2P leads on value. The Sol-Ark 15K-2P costs $1,299 less ($4,999 vs $6,298).
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 Sol-Ark 18K-2P for value ($350 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 | Sol-Ark 18K-2P | Sol-Ark 15K-2P |
|---|---|---|
| Overall rating | 4.1/5 | 4.1/5 |
| Value 30% | 70 $350 per kW of continuous output | 57 $417 per kW of continuous output |
| Solar input 20% | 80 28,800 W of panels, 500 V max, 3 MPPTs | 81 19,500 W of panels, 500 V max, 3 MPPTs |
| Efficiency 20% | 43 110 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
| Sol-Ark 18K-2P | Sol-Ark 15K-2P | |
|---|---|---|
| Output | ||
| Output voltage | 120/240 V split-phase | 120/240 V split-phase |
| Continuous output | 18,000 W | 12,000 W |
| Surge | 36,000 W | 24,000 W |
| Max efficiency | 97.6% | 97.5% |
| CEC efficiency | 97% | 96.5% |
| Idle draw | 110 W | 90 W |
| Transfer time | 5 ms | 5 ms |
| Parallel units | Up to 12 units | Up to 12 units |
| Solar | ||
| Max PV power | 28,800 W | 19,500 W |
| Max PV voltage (Voc) | 500 V | 500 V |
| MPPT range | 150 to 425 V | 150 to 425 V |
| MPPT trackers | 3 | 3 |
| PV current per tracker | 36 A | 26 A |
| Battery and grid | ||
| Battery voltage | 48 V | 48 V |
| Battery types | Lithium, lead-acid | Lithium, lead-acid |
| Max charge current | 350 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 | IP65 / NEMA 3R | IP65 / NEMA 3R |
| Dimensions | 34 x 19.4 x 12 in | 33 x 19.4 x 12 in |
| Weight | 137 lb | 135 lb |
| Warranty | 10 years | 10 years |
| Released | 2025-09 | 2022-08 |