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Sol-Ark 18K-2P Hybrid Inverter 18kW | 36kVA Surge

Sol-Ark 18K-2P Hybrid Inverter 18kW | 36kVA Surge
$6,119.00 - $6,119.00
$6,119.00
$6,119.00 - $6,119.00
$6,119.00
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Sol-Ark 18k Spec Sheet

View Spec Sheet HERE

18kW Continuous · 36kVA Surge · 28.8kW Solar · 350A Charger · 10 Years

Sol-Ark 18K-2P Hybrid Solar Inverter (18kW, 120/240V)

18,000W of continuous output directly from batteries, with 36kVA of surge for ten seconds. That surge figure is the one that matters for large homes: it's what lets a central air conditioner, a well pump and a heat pump start during an outage without the system stumbling. Three MPPTs across six DC ports take 28.8kW of usable solar, and AC coupling pushes total PV support past 40kW.

Dual 48V battery ports with a 350A charger, 200A grid passthrough, 5ms automatic transfer, generator auto-start, and Time-of-Day and VPP readiness. American-engineered firmware, IP65 / NEMA 3R enclosure, and Sol-Ark's 10-year standard warranty. Renewable Outdoors is an authorized Sol-Ark dealer — call us at (303) 876-7654 and we'll spec it against your service.

Sol-Ark 18K-2P Hybrid Solar Inverter
10-Year Warranty
Lowest Price Guarantee
Authorized Sol-Ark Dealer
Free Shipping
0% APR Financing
Expert Support: (303) 876-7654

Why the Sol-Ark 18K-2P

18kW Continuous from Battery

Enough to run a large house off storage alone — HVAC, well pump, range and everything else together.

36kVA Surge for 10 Seconds

Motor startup is where backup systems fail. This has the headroom for compressors and pumps in grid-down conditions.

28.8kW PV, 40kW+ With AC Coupling

Three MPPTs at 36A each across six DC ports — more solar capacity than any other residential inverter.

Dual 48V Ports, 350A Charger

Charges a large bank quickly and gives you room to expand storage without changing the inverter.

200A Grid Passthrough

Whole-home installation in front of a standard 200A service, rather than a critical-loads subpanel.

Time-of-Day and VPP Ready

Shift consumption to cheap hours and participate in utility virtual power plant programs where available.

What's Included

Sol-Ark 18K-2P inverter detail

In the Box

  • 1 × Sol-Ark 18K-2P hybrid inverter, pre-wired
  • Current transformers for grid sensing
  • Mounting hardware
  • Installation manual and warranty documentation

Batteries, PV modules, disconnects and conduit are separate purchases. A UL 9540 battery upgrade option is available for jurisdictions that require system-level certification — call us at (303) 876-7654 and we'll confirm what your inspector will want to see.

Sol-Ark 18K-2P Specifications

Continuous AC Output 18,000W at 240V; 15,600W at 120/208V
Peak Surge (10 seconds) 36,000W at 240V; 31,200W at 120/208V
Output Voltage 120/240V or 120/208V
Maximum Output Current 75A (batteries plus PV)
Grid Passthrough Current 200A
Nominal Grid Voltage Range 185–275V
Frequency 50/60Hz nominal, 55–65Hz range
Maximum Usable PV Power 28,800W
Maximum Rated PV Power (STC) 32,400W
AC Coupling Supported — over 40kW total PV capacity in AC-coupled configuration
Maximum PV Input Voltage 500V
MPPT Operating Range 150–425V
MPPT Trackers 3, with 2 strings each — 6 DC solar ports
Maximum Current per MPPT 36A
Battery Nominal Voltage 48V — 2 battery ports
Battery Operating Range 43–59V
Maximum Charge / Discharge Current 350A / 350A
Battery Compatibility Lead-acid or lithium
Transfer Time 5ms automatic
Peak Efficiency 97.6%
Parallel Capability Up to 12 units
Generator Support Generator auto-start and AC coupling support
Dimensions 34" × 19.4" × 12" (863 × 494 × 306mm)
Weight 137 lbs (62.14 kg)
Enclosure Rating IP65 / NEMA 3R
Operating Temperature −40°F to 140°F (−40°C to 60°C), derating above 45°C
Certifications UL 1741 CRD-Multimode, UL 1741 3rd SB, UL 1741 CRD-PCS
SKU 900-00071
Warranty 10 years

Documentation & Downloads

Sol-Ark 18K-2P Datasheet (Sol-Ark)

10-Year Warranty

Every Sol-Ark 18K-2P carries Sol-Ark's 10-year standard warranty, backed by a US company.

Lowest Price Guarantee

Found it cheaper elsewhere? Call us at (303) 876-7654 before you buy.

Authorized Sol-Ark Dealer

Genuine Sol-Ark hardware with full manufacturer support behind it.

Sol-Ark 18K-2P Hybrid Solar Inverter (18kW, 120/240V): Frequently Asked Questions

Who actually needs 18kW?
Large homes with central air conditioning and electric heat, houses with well pumps and shop equipment, and anyone who wants the whole house to behave normally during an outage rather than running a reduced load. If your service is 200A and you regularly use most of it, this is the size that matches. Below that, the 15K at 12kW is usually the better value.
Why does the 36kVA surge rating matter so much?
Because motors draw far more current starting than running. An air conditioner compressor that runs at 3kW might pull 15kW for a second or two on startup. A backup system that can't supply that will trip instead of starting the unit. 36kVA for ten seconds means the 18K can start almost anything a house contains, even off-grid.
Can it really support over 40kW of solar?
Yes, in an AC-coupled configuration — 28,800W of usable DC PV directly into the three MPPTs, plus AC-coupled capacity on top. Sol-Ark positions this as more solar capacity than any other residential inverter. Whether you can physically fit that much panel is another question, and one we're happy to work through with you.
How many can I parallel?
Up to 12 units. That takes it well past residential and into light commercial and microgrid territory. For anything beyond two or three units the system design matters more than the hardware choice, so let's talk it through before you order.
Which batteries should I pair with it?
It's battery-agnostic across 48V lithium and lead-acid with BMS communication, and the 350A charger means it will push a large bank hard. With 18kW of output, you want a battery bank rated to discharge at that level — pairing a big inverter with a small bank is the most common mistake we see. Call us at (303) 876-7654 and we'll match them properly.
What is the UL 9540 battery upgrade option?
UL 9540 is the safety standard for a complete energy storage system rather than its individual components, and a growing number of jurisdictions require it for permitted residential storage. The upgrade brings the inverter-plus-battery system into compliance. Whether you need it depends entirely on your local inspector.
Do I need a licensed electrician to install this?
Yes. A hybrid inverter ties into your main electrical service, and in every US jurisdiction that is licensed work requiring a permit and an inspection. The unit itself is pre-wired, which shortens the job considerably compared with assembling separate components, but it is not a DIY installation. We can talk you through what your installer will need before you order.
What does 'American-engineered firmware' mean in practice?
Sol-Ark writes and controls the inverter's firmware in the US rather than relying on a third-party overseas platform. For most buyers the practical effect is data handling and support: firmware issues get fixed by the same company that answers the phone, and system data isn't routed through infrastructure they don't control.
How wide is the operating temperature range?
−40°C to 60°C, which is unusually wide, with derating above 45°C. Combined with the IP65 / NEMA 3R enclosure that makes outdoor installation practical in most North American climates. Shade still helps in hot regions.
Do you offer financing or price matching?
Yes. We offer 0% APR financing options through Affirm at checkout, and our Lowest Price Guarantee applies — if you find this model cheaper at another authorized dealer, call us at (303) 876-7654 before you order and we'll take care of it.
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