WIT 100K: 100 kW Three-Phase Commercial String Inverter

WIT 100K, Overview

The WIT 100K is a 100 kW three-phase transformerless string inverter from WIT Energy, targeting commercial rooftop installations in the 250 kWp to 1.5 MWp range. At 100 kW, it occupies the same segment as the Sungrow SG110CX-P2 and Huawei SUN2000-100KTL-M1, above small commercial (3-30 kW single-phase) and well below utility-scale central inverters (500 kW+).

The 100K designation is common across commercial string inverters. WIT Energy positions the WIT 100K against established brands primarily on price: at approximately USD 7,800, it comes in 15-25% below comparable Sungrow and Huawei units with similar specifications. For installations specifying 10-15 inverters together, that price differential is meaningful.

10 MPPT Inputs and String Configuration

The WIT 100K supports 10 independent MPPT inputs with two string connections per MPPT, for 20 strings total. In a standard commercial rooftop installation with two or three roof orientations, this allows most orientations to have dedicated MPPT channels without combining mismatched strings.

For comparison, the AUXSOL ASN-110TL-PLUS reviewed separately on this site provides 12 MPPT inputs at 110 kW. If your installation has significant roof orientation variation, four or more distinct faces, the additional MPPT granularity of a 12-MPPT unit reduces annual mismatch losses. For simpler two-orientation rooftops, 10 MPPT is sufficient.

The maximum 1,100 V DC input voltage is standard for this class. String sizing for 400W panels (STC Voc ~49V) typically lands at 18-22 panels per string, which fits the 1,100V ceiling comfortably at -10C minimum ambient temperature.

98.7% Peak Efficiency

The WIT 100K achieves 98.7% peak efficiency at approximately 50-60% load. Euro efficiency (weighted for European irradiance distribution) is 98.1%. These figures are slightly below the 98.8-98.9% peak efficiencies of Sungrow and Huawei units at this power class, but within 0.2 percentage points, not a meaningful differentiator at commercial scale.

At 100 kW output, a 0.1% efficiency difference between inverters represents 100W of additional loss. Over 1,800 peak sun hours per year, that's 180 kWh annually, approximately EUR 54 at EUR 0.30/kWh feed-in rate. The WIT 100K's price advantage over comparable Sungrow units (USD 1,200-2,000 per unit) recovers this efficiency gap within the first year for most installations.

Fanless Cooling, Practical Implications

The WIT 100K uses natural convection cooling, which eliminates fan maintenance and the fan failure risk that commonly affects commercial inverters in the 5-15 year operational window. Fan replacement typically costs EUR 200-500 per unit including labor; at 10 units per installation, fan failure is a real O&M budget line item.

The trade-off for fanless operation is enclosure size. At 990 x 680 x 350 mm and 105 kg, the WIT 100K requires solid wall mounting or floor bracket installation. The weight means two-person installation is required and the installation brackets must be rated for the load plus dynamic stress from cable management.

Operating temperature range is -25C to +60C. The fanless cooling performs best below 45C ambient. Above 50C, the unit derates output to protect the power electronics, this is standard behavior for natural convection inverters. For installations in southern European climates with sustained summer heat, verify derating curves with WIT Energy before specifying.

Reactive Power Compensation

The WIT 100K supports reactive power output from 0.8 leading to 0.8 lagging power factor, configurable via the monitoring interface. This meets the reactive power requirements imposed by German (VDE-AR-N 4110), Italian (CEI 0-21), and Dutch grid codes for medium voltage connections above 100 kW.

For commercial installations in these markets that connect above the low-voltage threshold, reactive power capability is a grid connection requirement, not an optional feature. Without it, external reactive power compensation equipment adds EUR 8,000-20,000 to the installation cost.

Monitoring and Communication

Standard communication is RS485 (Modbus RTU) and Ethernet. Sunspec Alliance Modbus register mapping is supported, confirm register set version with WIT Energy's technical documentation before integrating with third-party SCADA systems.

WIT Energy's cloud monitoring platform handles up to 50 devices per account. For larger installations, the RS485 Modbus bus supports daisy-chaining up to 32 units before requiring a secondary communications gateway.

Optional WiFi communication is available for installations where Ethernet cabling is impractical, though Ethernet is preferred for commercial installations where reliability and data throughput matter.

How It Compares

Spec	WIT 100K	AUXSOL ASN-110TL-PLUS	Sungrow SG110CX-P2	Huawei SUN2000-100KTL-M1
Rated Power	100 kW	110 kW	110 kW	100 kW
Peak Efficiency	98.7%	98.8%	98.9%	98.8%
MPPT Inputs	10	12	12	10
Max DC Voltage	1100 V	1100 V	1100 V	1100 V
Reactive Power	Yes (0.8 pf)	Yes (0.8 pf)	Yes (0.8 pf)	Yes (0.8 pf)
Cooling	Fanless	Fanless	Fan-cooled	Fan-cooled
IP Rating	IP66	IP66	IP66	IP65
Warranty	10 years	10 years	10 years	10 years
Approx. price (USD)	~$7,800	~$8,500	~$9,200	~$10,500

The WIT 100K is the most affordable option in this comparison. Its weaker points relative to the AUXSOL and Sungrow alternatives are the MPPT count (10 vs 12) and the lower rated output power (100 kW vs 110 kW). For installations that can fully utilize the 10% additional capacity of a 110 kW unit, the effective cost-per-kW difference narrows.

The primary risk consideration is WIT Energy's service network. Unlike Sungrow and Huawei, which have established European service centers and O&M contract frameworks, WIT Energy's field support presence outside Asia is limited. For owner-occupied commercial buildings with in-house maintenance capability, this is manageable. For third-party-operated installations with strict uptime SLAs, verify local service coverage before specifying.

Sizing Context

A single WIT 100K powers approximately 250 solar panels at 400W each, covering 600-800 sq. m. of roof area. For a 750 kWp commercial installation, 7-8 units would be deployed across the array sections.

See our residential solar systems guide and power optimizer vs. microinverter comparison for system design context.

Rating based on 8 installer reviews.

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Related products: AUXSOL ASN-110TL-PLUS String Inverter, Anker SOLIX aPower 2 Home Battery