440W Hoymiles Plug-In Solar Ground Kit Complete Guide

The 440W ground kit pairs one full-size Hanersun 440W bifacial solar panel with one Hoymiles HiFlow Pro plug-in microinverter (360W or 420W output) to offset a portion of your daytime electricity use. It is our single-panel ground kit: one rigid panel on ground-mount racking for yards, gardens and the floor of balconies.

This guide covers what is included, panel placement, power output, safe setup and the questions to answer before buying.

This kit is not whole-home power or an outage-backup system. There is no battery in this kit, and the microinverter stops supplying power when the grid goes down.

In this guide

• Bottom line: who is this kit for?
• What is included and technical specifications
• Bifacial panels and ground placement
• How much electricity and money could it save?
• Is your home ready? Setup and permissions
• Certifications, warranty and limitations
• Frequently asked questions
• The next step

Bottom line: who is this kit for?

This kit is for homeowners or renters who have a sunny patch of ground and want the simplest start to plug-in solar: one full-size panel on ground racking that you set up once and leave. It suits a yard or garden, and it makes a good first kit if you want to offset a slice of your daytime power use without a rooftop installation.

Renters can use plug-in solar too; most people do not know they have options as a renter, and a ground kit like this one can move with you. Check if you may need your landlord's permission.

Before choosing this kit, check your space, circuit, property permissions and utility requirements. This is a large panel (about 5.7 x 3.7 ft and 51 lb), so plan for two people to more easily move and mount it. It is possible to do it yourself, but much easier with a helping hand. The kit generates power while the sun is shining; it does not replace your utility service.

What is included and technical specifications

The kit includes one 440W Hanersun bifacial panel, one metal ground-mount rack, one Hoymiles HiFlow Pro plug-in microinverter (360W or 420W version) with a 15-foot power cord, and the panel connection cables. Monitoring is through the free S-Miles Home app. A battery and an export-control meter are not included.

Specification	Value
Rated solar capacity (DC)	440W: 1 x 440W panel
Panel rating	440W, 0 to +3%, at standard test conditions
Panel type	N-type TOPCon monocrystalline, bifacial, full black
Panel efficiency	22.5%
Panel operating voltage/current	32.7V / 13.5A at maximum power
Panel open-circuit voltage / short-circuit current	38.7V / 14.3A
Panel dimensions / weight	67.8 x 44.6 x 1.2 in; about 51 lb
Panel junction box / fire rating	IP68; UL Type 29 fire rating
Microinverter model	Hoymiles HiFlow Pro LV: HMS-360-1WM-LV (360W) or HMS-420-1WM-LV (420W)
Rated AC output	360W or 420W; 120V; 60Hz
Solar inputs	1 MPPT input; recommended panel range 280-470W+ (360W) / 320-540W+ (420W)
MPPT range / maximum input voltage	16-60V / 60V
Maximum input current / short-circuit limit	14A / 20A
Grid connection	Standard Type B plug; 15 ft (4.57 m) 14 AWG power cord
Microinverter size / weight	7.2 x 6.5 x 1.2 in; 4 lb
Microinverter weather rating	NEMA 6 / IP67 (outdoor rated)
Microinverter operating temperature	-40 to 149 F (-40 to 65 C)
Connectivity / monitoring	Built-in Wi-Fi and Bluetooth; S-Miles Home app
Racking	Metal ground-mount racking, one rack for the panel; Material and finish: high-grade aluminum with a clear anodized finish, and 304 stainless steel hardware; Tilt angle: fixed at 35 degrees; Panel orientation: portrait; Frame rails: 36 x 54 x 65 in; Racking warranty: 20 years from SunModo

Table sources: the Hoymiles HiFlow Pro LV datasheet, Hanersun HN18N-54HT 440W panel datasheet, SunModo SunShield Awning one-sheet and the SunShield Awning installation and engineering guidelines

Ground-mount racking. The racking in this kit is SunModo's SunShield triangular aluminum frame, used here as a ground-level mount. It arrives folded flat and opens to a fixed 35-degree tilt, a practical year-round angle for many parts of the US. Each frame holds one panel in portrait orientation; this kit includes one frame.

• Mount: SunModo SunShield triangular aluminum frame, used as a ground-level mount

SunModo's engineering review covers this frame installed as a wall-mounted awning; in this kit it is used as a ground-level mount, so we do not claim wind, snow-load or code-certification ratings for the mount beyond what these documents state.

The panel and microinverter are a clean electrical match: the panel's 440W rating sits inside the inverter's recommended 280-470W panel range, and its voltage and current fit the inverter's input limits. The microinverter has one input for one panel.

Choosing between the 360W and 420W microinverter versions. Both versions of this kit include the same 440W bifacial panel and ground-mount racking; the only difference is which Hoymiles HiFlow Pro LV microinverter sends the power into your home. The two versions share the same size, outdoor rating, app monitoring and 12-year warranty, and the panel's 440W rating, voltage and current fit both versions' input ranges. The 360W version (HMS-360-1WM-LV) caps AC output at 360 watts, which keeps the kit under the roughly 400-watt line that some state plug-in solar rules use and can make setup simpler. The 420W version (HMS-420-1WM-LV) raises the kit power output to 420 watts.

What the cap means day to day: in strong midday sun, a 440W bifacial panel produces more than 360 watts of usable power. With the 360W version, the inverter trims that excess (this is called clipping); the 420W captures more of the panel power for your home. Because panels rarely sustain their full rating in real conditions, what clipping costs is smaller than the 60-watt nameplate gap suggests, and the oversized panel keeps the inverter working near its full output for more of the day, so mornings, evenings and brighter cloudy spells all add up.

As a rule of thumb: choose the 360W version if your state's rules favor staying under their wattage line or you want the simplest path to plugging in. Choose the 420W version if your state allows it and getting the most out of every sunny day, including the bifacial bonus, matters more. Check the rules in your state before choosing. The savings estimates below use the same figures for either version, because the yearly production difference between them is small.

420W version specs: HMS-420-1WM-LV, rated AC output 420W at 120V, 60Hz; 1 MPPT input, recommended panel range 320-540W+; MPPT range 16-60V, maximum input voltage 65V; maximum input current 14A, short-circuit limit 25A; standard Type B plug with a 15 ft (4.57 m) power cord; NEMA 6 / IP67 outdoor rating; 12-year warranty. All other specifications match the 360W version in the table above.

Bifacial panels and ground placement

Bifacial panels collect light on their front and on their back, where light reflects off the ground. Capturing that reflected light means you can produce slightly more energy than the panel rating: expect a few percent extra in typical conditions, with the best gains over light surfaces such as pale gravel.

Placement still drives most of your production. Aim the panel south if you can, east or west is typically the second-best option; keep the panel clear of shade from trees, fences and buildings; and follow the racking instructions for tilt and anchoring. Panels collect the most power when the sun's rays hit them square-on, and even a well-placed panel will not produce its full rated 440W all day. Heat, wiring and conversion losses are normal.

How much electricity and money could it save?

How we calculate it: We use PVWatts to model production hour by hour through a typical weather year, using this kit's panel capacity and maximum inverter output. The comparison assumes premium panels facing south at 35 degrees, no shade, and 11.42% system losses, with 96% nominal inverter efficiency. PVWatts accounts for temperature, inverter efficiency and the inverter's output cap. We do not apply the old flat 15% reduction on top. The common angle is a comparison assumption, not a mounting instruction; follow the kit's installation instructions.

What bifacial panels add. This panel is bifacial: the front collects sunlight like any panel, and the back also collects light that bounces off the ground. A panel that is not bifacial cannot use that reflected light, so this kit produces slightly more energy than it would with an ordinary panel of the same size. Hanersun rates the back side at 80% (plus or minus 5%) of the front, and its datasheet lists the panel at 488W instead of 440W with a standard amount of reflected light on the back (135W per square meter), about 11% more power in that lab test. Reflected light is weaker than in the test, the racking blocks some of it, and the gain depends on what is under the panel: light gravel gives more, grass or soil gives less. NREL modeling and field testing puts annual bifacial gains at roughly 4% to 11% depending on the panel type and site. We count 7.5%, the average of that range, for a low-to-the-ground yard kit.

The model includes the existing 7.5% assumed bifacial gain once, in the panel capacity input. It does not add a second bifacial gain. Actual reflected-light gains depend on the site.

Two inverter choices: The 360W and 420W versions are modeled separately. A higher inverter rating does not guarantee a larger annual result at every location: PVWatts also models part-load efficiency, and the differences here are small.

360W microinverter:

• Seattle, Washington: 543kWh a year x $0.1463/kWh = about $79 a year, or $7 a month. That is about 5% of the $138.18 average monthly bill.
• Baltimore, Maryland: 682kWh a year x $0.2140/kWh = about $146 a year, or $12 a month. That is about 6% of the $202.12 average monthly bill.
• Los Angeles, California, high-end example: 823kWh a year x $0.2975/kWh = about $245 a year, or $20 a month. That is about 14% of the $146.83 average monthly bill.

420W microinverter:

• Seattle, Washington: 542kWh a year x $0.1463/kWh = about $79 a year, or $7 a month. That is about 5% of the $138.18 average monthly bill.
• Baltimore, Maryland: 689kWh a year x $0.2140/kWh = about $147 a year, or $12 a month. That is about 6% of the $202.12 average monthly bill.
• Los Angeles, California, high-end example: 830kWh a year x $0.2975/kWh = about $247 a year, or $21 a month. That is about 14% of the $146.83 average monthly bill.

Rates and baseline bills come from ElectricityPlans' EIA-based data for August 2026. The baseline bill is average monthly use multiplied by that month's rate, not a seasonally adjusted bill. The state rate is a comparison proxy, not your exact avoided tariff: fixed charges, time-of-use pricing and export rules can change the result. Monthly values are annual averages, not a forecast for each month. Dollar figures are rounded; bill percentages use the displayed whole-dollar monthly values. Every example assumes full self-use with no export credit.

Do not assume that exported power earns a credit or that every meter handles it the same way. Check our state tracker or ask your utility how it will measure and bill your setup, including any required approval or notification. This kit is not zero-export on its own.

Is your home ready? Setup and permissions

• A sunny, unshaded patch of ground for the panel on its racking, in a safe, secure placement. 
• A suitable outdoor outlet on a dedicated circuit, with proper grounding and GFCI protection.
• A cable route that reaches the outlet within the 15-foot power cord, or a 14-gauge waterproof, weather-resistant, and outdoor-rated extension cord.
• Any required landlord or HOA permission, plus state, local and utility checks.

At a high level: assemble the racking, mount the panel, connect the panel to the microinverter, plug in to the outlet, and connect the microinverter to the S-Miles Home app. Have a qualified electrician assess any circuit changes, new outlet work or uncertainty about your setup. If you move the kit, recheck the electrical requirements at the new location.

Related: How to check a dedicated circuit | GFCI outlets and plug-in solar | Plug-in solar rules by state

Certifications, warranty and limitations

Hoymiles lists the HiFlow Pro LV microinverter as certified to UL 1741 and UL 3700 and compliant with IEEE 1547, which includes anti-islanding and rapid-shutdown safety functions, and markets it as the first plug-in solar microinverter certified to UL 3700. Certification at the microinverter level is not the same as certification of the kit as a whole system, and no whole-kit certification is claimed. Rules differ by state: some states ask for a certified microinverter, while others look at the whole system. Check our state guide before buying.

Hanersun's published global warranty document lists a 25-year product warranty and a 30-year linear power-output warranty for its panels. 

Hoymiles warranties the microinverter for 12 years. SunModo covers the racking for 20 years. These are component terms, not a single warranty for the whole kit. Weather resistance does not replace installation instructions. The microinverter is outdoor rated (NEMA 6 / IP67); still follow the manual on placement and cable handling.

Related: What plug-in solar certification labels mean

Frequently asked questions

Will this cover my whole electricity bill?

No. It is designed to offset a portion of daytime electricity use: in our state examples, roughly 4% to 14% of an average home's bill. Your savings depend on your site, household use and electricity rate. It does not eliminate utility service or fixed charges.

Does it work during a blackout or include a battery?

No. There is no battery in this kit, and the grid-connected microinverter stops output during a blackout. Do not buy this kit as emergency backup power.

What happens on cloudy days or in shade?

Output falls when less sunlight reaches the panel. Keep the panel clear of shadows from trees, fences and buildings. A bifacial panel still collects some reflected and diffuse light, but shade is the enemy of production.

Can I install it on a roof or balcony?

This kit is sold for ground mounting. Rooftop systems follow different rules and need different equipment, and the included racking is not a roof product. You can place the ground mount on the floor of your balcony; the mount is not suitable for a railing mount. 

Do I need a permit, utility approval or a new meter?

That depends on your location and utility. Check before buying or installing. Ask the utility specifically about export, meter compatibility and billing.

Can I add more panels later?

The microinverter has one input sized for this panel. To grow, you would add a second kit with its own microinverter on its own circuit rather than another panel on this one. Most states with plug-in solar bills allow up to 1,200W of plug-in solar per dwelling unit (Colorado allows up to 1,920W).

Can I move it later?

Yes, though the panel is large (about 51 lb), so plan for two people. Recheck placement, electrical requirements and local rules at the new site.

The next step

If you have a sunny patch of ground and want a simple first step into solar, explore our 440W ground kit. Not sure about placement, your outlet or your meter? Ask us before you order.

Check out the 440W ground kit