Growatt WIT 100K-HU Commercial Storage Inverter

Growatt WIT 100K-HU, Overview

The Growatt WIT 100K-HU is a 100 kW three-phase hybrid inverter for commercial storage projects, pairing a 100 kW PV input with a battery interface, a built-in UPS and black start. It is not a plain PV string inverter, and that distinction decides whether it belongs on your bill of materials at all. If what you want is grid-tied PV with no battery, Growatt's MAX and MID series are the commercial string inverters to price instead. WIT is the storage line.

It sits at the top of the WIT 50-100K-HU/AU series, and the North American variant is the WIT 100K-HU-US at 480 Vac. Some distributors write the SKU as WIT100K-H, which is the same unit.

Growatt prices the WIT 100K-HU below Sungrow and Huawei equivalents, which is the same play it runs across its range. European distributor listings sit between roughly EUR 6,950 and EUR 8,700 depending on seller and VAT treatment, so USD 7,800 is a fair working figure at the low end of that band. For installations specifying 10 or more units together, that differential is meaningful.

10 MPPT Inputs and String Configuration

The WIT 100K-HU supports 10 independent MPPT inputs with two string connections per MPPT, for 20 DC inputs total, at up to 40 A per tracker and 320 A across the unit. In a standard commercial rooftop installation with two or three roof orientations, that lets most orientations have dedicated MPPT channels without combining mismatched strings.

For comparison, the AUXSOL ASN-110TL-PLUS reviewed separately on this site runs 8 MPPT and 16 strings at 110 kW. So the Growatt gives you more tracking granularity per unit despite the lower rating, which is the opposite of what the model numbers suggest. On a roof with four or more distinct faces, that matters more than the 10 kW of extra output.

Watch the voltage window when you size strings. The maximum DC input is 1,100 V, but the MPPT tracking range only runs from 180 V to 800 V. The 1,100 V number is a survival limit, not a design target: size the strings so cold-morning open-circuit voltage stays inside the tracking window, or the array spends the best part of a winter day outside the range where the inverter can actually track it.

Storage, Backup and Generator Control

This is the part a string-inverter comparison misses. The WIT 100K-HU carries a battery interface that supports both lithium and lead-acid packs, a built-in UPS function, and black start, so the system can come back up from battery with no grid present. AC overload is 110% continuous, and unbalanced output is rated at 100%, meaning a single phase can take the full rated load. Multi-unit systems scale to 300 kW.

There's also remote diesel generator control, which is the feature that decides these projects in markets with unreliable supply. A site running PV plus battery plus generator needs one controller sequencing all three, and paying for a separate one erases the price advantage.

Type II surge protection is fitted on both the DC and AC sides.

98% Peak Efficiency

Growatt rates the WIT 100K-HU at 98% max efficiency, with 98% European efficiency quoted by EU distributors. That puts it roughly a percentage point behind the Sungrow and Huawei units at this class. At 100 kW output, a percentage point is about a kilowatt of extra heat at full load, which is real but small next to a four-figure price gap per unit.

Anyone who picks a commercial inverter on the third decimal place of an efficiency figure is optimising the wrong variable. Grid code compliance, service response time and battery compatibility will cost or save far more over 15 years.

Cooling and Installation

The WIT 100K-HU is actively cooled. Fans mean fan servicing, and fan replacement in the 5-15 year window is a genuine O&M budget line at EUR 200-500 per unit including labour. Budget for it rather than discovering it in year eight.

Physically this is a cabinet, not a wall box. At 820 x 1350 x 510 mm and 143 kg, plan for a floor stand or a structural mount rated for the load plus dynamic stress from cable management, and a two-person lift with proper handling gear. Distributor listings run as high as 160 kg depending on shipping configuration.

Operating temperature range is -30 C to +60 C. Above the derating threshold the unit reduces output to protect the power electronics, which is standard behaviour. For southern European sites with sustained summer heat, ask Growatt for the derating curve before you finalise the yield model.

Reactive Power Compensation

The WIT 100K-HU 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, USB and WLAN, with monitoring running on Growatt's own platform through a ShineWiLAN-X2 or ShineSEM-XA-R datalogger. Confirm the Modbus register set against Growatt's technical documentation before wiring the unit into a third-party SCADA system, since register maps change between firmware generations.

The RS485 bus follows the usual practical limit of 32 nodes before you need a second gateway, so plan the communications topology alongside the electrical one on larger sites.

How It Compares

Spec	Growatt WIT 100K-HU	AUXSOL ASN-110TL-PLUS	Sungrow SG110CX-P2	Huawei SUN2000-100KTL-M1
Rated Power	100 kW	110 kW	110 kW	100 kW
Type	Hybrid storage	PV string	PV string	PV string
Peak Efficiency	98%	98.60%	98.9%	98.8%
MPPT Inputs	10	8	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	Fan-cooled	Not published	Fan-cooled	Fan-cooled
IP Rating	IP66	IP66	IP66	IP65

The comparison is only half fair, and it's worth saying so. The other three are grid-tied PV string inverters; the Growatt is a storage inverter with a battery port, a UPS and generator control built in. On efficiency and raw MPPT count it doesn't win. On what it does for the money, a pure string inverter isn't competing at all once storage is in the scope.

Growatt's European distribution is broad - the unit is stocked by PVshop, Panpower, sun.store, solsol and solartraders among others - so stock and warranty paperwork are rarely the constraint. The real question on a commercial project is who holds the O&M contract and how fast they can get a swap unit on site. Ask that before you ask about efficiency.

Sizing Context

A single WIT 100K-HU takes about 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, and at 300 kW of scalable capacity per system you'll be grouping them anyway.

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

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Related products: AUXSOL ASN-110TL-PLUS String Inverter, Growatt WIT 4-25K-XHU Hybrid Inverter