What APsystems microinverter models are available?

APsystems offers the QT2D (4-input, 1.5 kW, ideal for bifacial arrays), DS3-S (2-input, 880W, standard residential), EZ1-M (2-input, 800W, entry-level single-phase), and QT2-D-DUO (4-input, 1.5 kW, 3-phase commercial). All achieve 96.5% peak efficiency and include a 12-year standard / 25-year extended warranty.

How does APsystems compare to Enphase for microinverters?

APsystems achieves comparable 96.5% efficiency to Enphase IQ8 at roughly 25–30% lower inverter cost per watt. The QT2D's 4-input multi-MPPT design outperforms Enphase for bifacial panels and complex roof layouts. Enphase has a larger US installer network and simpler cabling with the IQ bus connector; APsystems wins on cost and 4-panel-per-unit flexibility.

Is APsystems NEC rapid shutdown compliant?

Yes. All current APsystems microinverters (DS3-S, QT2D, EZ1-M, QT2-D-DUO) are NEC 2017/2020 rapid shutdown compliant. The microinverter architecture inherently limits DC voltage at the module level — no separate rapid shutdown transmitters or module-level electronics are required, unlike string inverters.

What is the APsystems ECU monitoring gateway?

The Energy Communication Unit (ECU) is APsystems' monitoring gateway. The ECU-R handles residential systems; the ECU-C handles larger commercial arrays. It communicates with each microinverter via powerline (PLC) — no extra wiring — and uploads panel-level data to the APsystems EMA cloud platform accessible via web and mobile app.

When should I choose APsystems QT2D over Hoymiles?

Choose APsystems QT2D when you have bifacial panels, a complex shaded roof, or need 3-phase commercial output. Hoymiles is typically $0.13–0.15/W vs APsystems $0.18–0.25/W — Hoymiles wins on price for simple south-facing arrays. APsystems QT2D wins on 4-input multi-MPPT performance for bifacial and mismatched panel configurations.

APsystems Microinverter Calculator

APsystems value-tier microinverters — enter panel count (2–32), wattage (380–650W), and system type to get your optimal model (QT2D 4-input for bifacial, DS3-S/EZ1-M for standard, QT2-D-DUO for 3-phase commercial), inverter count, cost vs Enphase and Hoymiles, and ECU monitoring details.

System inputs

Panel count?

panels

Panel wattage?

System type?

APsystems microinverter results

Recommended model

DS3-S — 2-input 880 W

Standard residential 2-panel microinverter — plug-and-play, rapid shutdown compliant

Metric	Value
System size	6.40 kW (16 × 400W)
Microinverters needed	8 × DS3-S — 2-input 880 W
Total AC output capacity	7.04 kW
Microinverter efficiency	96.5%
Total system cost range	$3,136 – $4,800
Net cost after 30% ITC	$2,778
Inverter cost only ($/W)	$0.22/W (vs Enphase ~$0.30/W)
Estimated year-1 production	10,933 kWh/yr
Warranty	12-yr standard / 25-yr extended (ECU-monitored)
ECU monitoring	APsystems ECU-R / ECU-C gateway — panel-level monitoring included
vs Hoymiles	APsystems 2-input multi-MPPT — better for bifacial & mismatched strings
vs Enphase	APsystems ~30% lower inverter cost/W with comparable 96.5% efficiency
Verdict	APsystems EZ1-M/DS3-S: best value-tier microinverter — Hoymiles alternative with better US market warranty support

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How to Use This Calculator

Enter your panel count and wattage

Input the total number of solar panels in your system (2–32 for standard APsystems deployments) and the rated wattage per panel. APsystems microinverters support panels from 380W to 650W. The calculator selects the optimal APsystems model based on your panel wattage and system type — the 4-input QT2D for high-watt or bifacial panels, the 2-input DS3-S for standard residential, the EZ1-M for small systems, and the QT2-D-DUO for commercial 3-phase applications.

Select residential or commercial

Residential systems in most markets are single-phase. If your commercial site requires balanced 3-phase output — common for offices, warehouses, and C&I rooftops — select commercial. The QT2-D-DUO microinverter delivers 3-phase AC output, eliminating the need for a central string inverter on smaller commercial sites while maintaining the panel-level optimization benefits of microinverter architecture.

Read your results

The calculator outputs: how many microinverters you need, total AC output capacity, cost per watt vs Hoymiles and Enphase, estimated year-1 production at 96.5% efficiency, warranty details (12-yr standard / 25-yr extended), and whether APsystems or a competing brand is better for your specific panel configuration.

The Formula

Inverter count = ceil(panel count ÷ inputs per microinverter) Total AC output = inverter count × max output per unit (W) System cost range: Panel cost = system kW × $0.30–0.50 per W Inverter cost = system kW × $0.18–0.25 per W (APsystems value tier) Total = panel + inverter costs Year-1 production = system kW × 5 PSH × 365 days × 96.5% microinverter eff × 97% derate Net cost after ITC = total cost × (1 − 0.30)

Example: Bifacial 4-input system, 20 panels × 580W

Panel array20 × 580W = 11.6 kW

Model selectedQT2D (4-input, 1.5 kW) — best for bifacial

Microinverters needed5 × QT2D units

Total AC output5 × 1.5 kW = 7.5 kW

Inverter cost (at $0.21/W)11,600W × $0.21 = $2,436

Enphase equivalent cost~$3,480 (at $0.30/W)

APsystems saving vs Enphase~$1,044 on inverters alone

Year-1 production11.6 × 5 × 365 × 0.965 × 0.97 = 19,873 kWh

At 4 inputs per unit, the QT2D independently optimizes each of the 4 panels it controls. In a bifacial system where rear-side gain varies by panel position, this multi-MPPT architecture recovers 3–8% more energy than 2-input competitors — the key reason APsystems recommends QT2D for bifacial arrays.

FAQ

What is the difference between APsystems QT2D and Enphase IQ8? ▼

The APsystems QT2D has 4 DC inputs (vs Enphase IQ8's 1 input per unit) meaning each QT2D controls up to 4 panels with individual MPPT tracking — comparable to 4 Enphase units at roughly 25–30% lower inverter cost per watt. Both achieve 96.5% CEC efficiency. The QT2D is particularly advantageous for bifacial panels and complex roof orientations where panels receive different irradiance. Enphase has a larger US installer network and the IQ system bus simplifies wiring; APsystems wins on cost and 4-input flexibility.

Does APsystems have rapid shutdown compliance? ▼

Yes. All current APsystems microinverters (DS3-S, QT2D, EZ1-M, QT2-D-DUO) are NEC 2017/2020 rapid shutdown compliant. When the main breaker is tripped or the rapid shutdown initiator activates, each microinverter cuts its DC-side voltage below 30V within 30 seconds as required by code. This is built into the microinverter architecture — no additional rapid shutdown transmitters are required, unlike central string inverters that need separate module-level electronics.

What is the ECU gateway and do I need one? ▼

The Energy Communication Unit (ECU) is APsystems' monitoring gateway. The ECU-R handles residential systems up to 150 microinverters; the ECU-C handles larger commercial arrays. The ECU connects to your home network and communicates with each microinverter via powerline (PLC) communication — no additional wiring needed. It uploads panel-level data to the APsystems EMA (Energy Monitoring & Analysis) cloud platform, accessible via web browser and mobile app. One ECU per installation is required for monitoring; the system operates without it but you lose panel-level visibility.

Is the 25-year warranty on APsystems microinverters real? ▼

APsystems offers a 12-year standard product warranty that can be extended to 25 years through their extended warranty program, typically purchased at installation. The extended warranty covers defects in materials and workmanship. APsystems has been manufacturing microinverters since 2009 and has shipped over 3 million units globally. When purchasing the extended warranty, verify the warranty is backed by APsystems USA (North American entity) and confirm the claim process with your installer before signing — as with any brand, the warranty is only as good as the company's longevity.

When should I choose APsystems over Hoymiles? ▼

Choose APsystems QT2D when: (1) you have bifacial panels — 4-input MPPT recovers more energy from rear-side variation; (2) your roof has complex shading or multiple orientations; (3) you need 3-phase commercial output (QT2-D-DUO); (4) your installer prefers the APsystems ecosystem and ECU monitoring. Choose Hoymiles when: cost is the primary driver (Hoymiles is typically $0.13–0.15/W vs APsystems $0.18–0.25/W), you have a simple south-facing array with minimal shading, or your installer already has Hoymiles tooling and support.