How much does a 400 kwh solar system cost?

Written by

Tara Farmer

December 4, 2023

Edited by

Tamatha Hazen

Fact-checked by

Kristen Cramer

Solar panels cost by system size

Solar panels cost $3.00 to $4.50 per watt installed on average, with homeowners spending about $3.75 per watt before factoring in available solar incentives. A 6- to 10-kW solar panel installation costs $12,600 to $31,500 after the 30% federal tax credit. Solar panel prices depend on the size, type, and quality.

Average cost of solar panels by system size System size
(in kilowatts) Average installed cost
(before incentives) Average final installation cost*
(after 30% tax credit) 3 kW $9,000 – $13,500 $6,300 – $9,500 4 kW $12,000 – $18,000 $8,400 – $12,600 5 kW $15,000 – $22,500 $10,500 – $15,800 6 kW $18,000 – $27,000 $12,600 – $18,900 8 kW $24,000 – 36,000 $16,800 – $25,200 10 kW $30,000 – $45,000 $21,000 – $31,500 12 kW $36,000 – $54,000 $25,200 – $37,800

*Total cost may be lower with additional state and local incentives.

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Cost to install solar panels by state

Residential solar panel prices vary from state to state. Your estimated installation costs and potential savings depend on the local electricity rates, your household electricity usage, and the incentives available in your area.

Cost of solar panels by state State Average cost per watt* Average total cost for 6- to 10-kW system* Average total cost for 6- to 10-kW system*
(after 30% tax credit) Alabama $2.02 – $2.85 $12,100 – $28,500 $8,500 – $20,000 Alaska $2.23 – $3.13 $13,400 – $31,300 $9,400 – $21,900 Arizona $2.53 – $4.31 $15,200 – $43,100 $10,600 – $30,200 Arkansas $2.67 – $3.06 $16,000 – $30,600 $11,200 – $21,400 California $2.50 – $3.45 $15,100 – $34,500 $10,500 – $24,200 Colorado $2.82 – $4.60 $16,900 – $46,000 $11,800 – $32,200 Connecticut $2.68 – $4.20 $16,100 – $42,000 $11,300 – $29,400 Delaware $2.62 – $3.80 $15,700 – $38,000 $11,000 – $26,600 Florida $2.60 – $3.30 $15,600 – $33,000 $10,900 – $23,100 Georgia $2.60 – $3.74 $15,600 – $37,400 $10,900 – $26,200 Hawaii $2.41 – $2.79 $14,500 – $27,900 $10,100 – $19,500 Idaho $2.93 – $3.46 $17,600 – $34,600 $12,300 – $24,200 Illinois $3.16 – $3.76 $19,000 – $37,600 $13,300 – $26,300 Indiana $2.82 – $4.10 $16,900 – $41,000 $11,800 – $28,700 Iowa $3.01 – $4.01 $18,100 – $40,100 $12,600 – $28,100 Kansas $2.39 – $3.34 $14,300 – $33,400 $10,000 – $23,400 Kentucky $2.34 – $3.65 $14,000 – $36,500 $9,800 – $25,600 Louisiana $2.64 – $3.80 $15,800 – $38,000 $11,100 – $26,600 Maine $2.92 – $3.80 $17,500 – $38,000 $12,300 – $26,600 Maryland $2.93 – $3.54 $17,600 – $35,400 $12,300 – $24,800 Massachusetts $3.54 – $4.31 $21,200 – $43,100 $14,900 – $30,200 Michigan $2.93 – $4.06 $17,600 – $40,600 $12,300 – $28,400 Minnesota $2.98 – $4.03 $17,900 – $40,300 $12,500 – $28,200 Mississippi $2.64 – $3.14 $15,800 – $31,400 $11,100 – $22,000 Missouri $2.82 – $3.37 $16,900 – $33,700 $11,800 – $23,600 Montana $2.42 – $2.84 $14,500 – $28,400 $10,200 – $19,900 Nebraska $2.83 – $3.07 $17,000 – $30,700 $11,900 – $21,500 Nevada $2.51 – $3.80 $15,100 – $38,000 $10,500 – $26,600 New Hampshire $3.10 – $4.22 $18,600 – $42,200 $13,022 – $29,500 New Jersey $2.95 – $4.50 $17,700 – $45,000 $12,400 – $31,500 New Mexico $2.38 – $4.60 $14,300 – $46,000 $10,000 – $32,200 New York $2.77 – $4.31 $16,600 – $43,100 $11,600 – $30,200 North Carolina $2.63 – $4.70 $15,800 – $47,000 $11,000 – $32,900 North Dakota $2.42 – $2.54 $14,500 – $25,400 $10,200 – $17,800 Ohio $2.72 – $3.41 $16,300 – $34,100 $11,400 – $23,900 Oklahoma $2.56 – $3.13 $15,400 – $31,300 $10,800 – $21,900 Oregon $3.02 – $3.70 $18,100 – $37,000 $12,700 – $25,900 Pennsylvania $3.05 – $3.55 $18,300 – $35,500 $12,800 – $24,900 Rhode Island $2.87 – $5.80 $17,200 – $58,000 $12,100 – $40,600 South Carolina $2.66 – $3.45 $16,000 – $34,500 $11,200 – $24,200 South Dakota $2.39 – $2.50 $14,300 – $25,000 $10,000 – $17,500 Tennessee $2.79 – $3.58 $16,700 – $35,800 $11,700 – $25,100 Texas $2.60 – $3.00 $15,600 – $30,000 $10,900 – $21,000 Utah $2.62 – $4.80 $15,700 – $48,000 $11,000 – $33,600 Vermont $3.01 – $3.85 $18,100 – $38,500 $12,600 – $27,000 Virginia $2.85 – $3.59 $17,100 – $35,900 $12,000 – $25,100 Washington $2.82 – $4.30 $16,900 – $43,000 $11,800 – $30,100 Washington, DC $3.29 – $3.99 $19,700 – $39,900 $13,800 – $27,900 West Virginia $2.84 – $3.39 $17,000 – $33,900 $11,900 – $23,700 Wisconsin $2.88 – $3.41 $17,300 – $34,100 $12,100 – $23,900 Wyoming $2.57 – $2.81 $15,400 – $28,100 $10,800 – $19,700

*Total cost may be lower after tax credits, rebates, and other incentives.

Solar resource map of the US (Source: National Renewable Energy Laboratory)

Solar panel cost by type

Solar panels come in three types. Monocrystalline, made from high-grade silicon, costs the most but is the most efficient. Polycrystalline, made from silicon fragments, offers mid-range cost and efficiency. Thin-film, made from non-crystalline silicon layers, is the cheapest but requires more space for less efficiency.

Solar panel prices by type - ChartSolar panel prices by type Solar panel type Average cost per watt
(before installation) Efficiency Monocrystalline $1.00 – $1.80 17% – 22% Polycrystalline $0.80 – $1.00 15% – 17% Thin-film $0.50 – $1.00 11% – 14%

Solar panels on the tile roof of a house

Solar cost per kWh

Residential solar panel systems cost $0.09 to $0.11 per kilowatt-hour (kWh) installed on average, though prices vary greatly depending on the type of panels and how much daily sun they receive. In comparison, the residential electricity rate in the US averages $0.14 to $0.16 per kWh.

• While a kilowatt is a measure of power, a kilowatt-hour is a measure of energy.

• Solar panel systems are typically priced per watt. However, when calculating the energy cost savings, people usually consider the cost per kilowatt-hour, with most homes in the US using 900 to 1,000 kWh per month.

Use the following formula to calculate what size solar panel system you need to cover your monthly electricity usage:

Monthly electricity use (in kWh) ÷ Monthly peak sun hours = kW system needed

Example:

1,000 kWh per month usage ÷ 170 peak sun hours per month = 5.88kW system needed

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Calculating kwh energy production from solar panel system - map

Solar panel installation cost factors

Several factors affect the cost of solar panel system installation, including:

• Energy usage / system size – Homes with higher energy needs require larger solar panel systems. A larger system residential or commercial system costs more in total to install but often costs less per watt than a smaller installation.

• Location – Electricity rates and solar incentives vary by city and state. In general, homeowners in areas with high electricity rates stand to save more money over time with solar panel installation.

• Climate – Local weather conditions and the amount of sunlight your roof receives affect how many solar panels you need to become energy independent. Areas with long winters or periods of harsh weather typically need more panels than an area with sunny days year-round.

• Installation difficulty – Installing solar panels on a simple, easy-to-access roof with a standard 20- or 30-degree pitch takes less time and costs less than installations on a complex or difficult to reach roof.

• Shade – Trees shading the roof may need trimming for your solar panels to get optimal sun exposure.

• Roof age & condition – Since most solar panels last 25+ years, consider replacing an older roof before installing a new solar panel system.

• Brand & installation company – Prices, options, and warranties vary by company and manufacturer. Well-established and highly rated companies often charge more but you'll have peace of mind that they'll be in business through the life of your solar panel warranty.

• Purchase method – If your budget supports it, paying up front for the entire system is the most cost-effective option. A solar loan lets you make payments over time with little to no money down, but the total cost typically ends up being higher.

• Time of year – Solar panel installations during the winter months may cost less due to the decreased demand.

• Labor & soft costs – Soft costs, or all the non-material costs involved with solar panel installation, typically make up more than 50% of the total cost. Installation labor accounts for 10% to 20% depending on local rates and licensing requirements. Other soft costs include permit & interconnection fees, marketing, and operational costs.

SolarAPP+ (Solar Automated Permit Processing) is a web-based system designed to speed up the permit approval and interconnection process for solar system installations, thereby reducing the total cost. Many areas in California, Arizona, and Texas have already adopted this system.

Solar equipment

Materials make up 35% to 45%+ of the total cost for most solar panel system installations. Brand and equipment quality impact the total. Besides the solar panels themselves, most solar energy systems require mounting structures, an inverter, and sometimes an electrical panel upgrade.

• Mount type – Fixed panel mounts cost the least but cannot be moved. Adjustable mounts cost more but may be moved as needed for the best sun exposure. Self-adjusting mounts cost the most but significantly increase the system's efficiency.

• Inverter – Solar inverters cost $1,500 to $3,000 installed on average.

• Electrical panel – Experts recommend a 200-amp electrical panel at minimum when installing a solar panel system. Upgrading to 200-amp electrical panel costs $1,300 to $2,500.

Solar batteries, inverter, and electric vehicle charging station in a home garage.

Grid-tied vs. off-grid solar systems

Grid-tied, off-grid, and hybrid solar systems each have different components and costs.

• Grid-tied systems connect to the public electrical grid and do not require battery storage.

• Hybrid systems are tied to the grid but also have backup battery storage. Adding a solar battery storage system costs $5,600 to $11,200 installed on average (after tax credits), depending on the capacity, type, and brand.

• Off-grid solar systems cost $40,000 to $80,000 installed and typically have battery storage and a backup generator to supply power when the solar panel energy is not sufficient. By itself, a generator costs $900 to $4,000 for a connected portable unit or $6,000 to $11,000 total for a whole-house standby generator.

Solar tax credits & incentives

Incentives and rebates to help reduce the cost of solar panel installation vary by state. The table below details several of these potential incentives. Check the Database of State Incentives for Renewables & Efficiency (DSIRE) to confirm the available incentives in your area and their qualification requirements.

Solar incentives Incentive type Description Residential Clean Energy Credit
(formerly Solar Investment Tax Credit or ITC) A 30% federal tax credit is available on most solar systems installed between 2022 and 2032. Property tax exemptions or exclusions If the solar panel installation increases the home's value, the added value is exempt from property tax. Sales tax exemption Solar panels and solar energy system components are exempt from sales tax in many states. Net metering Homeowners receive electric bill credits for the excess energy they send back to the public grid. Power Purchase Agreement (PPA) The utility or solar company owns, installs, and maintains the equipment; the homeowner pays a guaranteed fixed rate for the electricity used during the contract term (typically 10 to 20 years). Solar Renewable Energy Credits (SRECs) In some states, homeowners can earn additional money–$1 for every MWh—for the electricity their solar systems generate. Solar lease Like a PPA, the solar company owns, installs, and maintains the equipment. The homeowner pays a monthly fee to power their home with the energy generated. State, local government, & utility company incentives Solar tax incentives and rebates vary by location.

Additional costs

Additional costs to consider when installing solar panels include:

• Maintenance – Solar panel cleaning costs $10 to $20 per panel or $150 to $500 total on average. Some installation contracts include an annual inspection and cleaning service. If you have a solar lease, the provider typically covers the maintenance and repairs.

• Insurance – Your homeowners insurance premiums may increase after installing a new solar panel system.

• Roof repairs – Solar panels should be installed on a roof in good condition. Unexpected repairs during the installation increase the total cost.

• Monitoring system – Some solar companies offer a monitoring system for a $10 to $20 monthly fee. If you install your own monitoring system, don't forget to factor it into your total cost.

Inspect your solar panel system at least once or twice per year to maximize its lifespan and prevent more costly repairs.

Buying vs. leasing solar panels

If your budget supports it, paying up front for the entire system is the most cost-effective option, providing the most benefits and highest long-term savings. You can take advantage of tax credits and incentives and participate in your utility company's net metering program.

Other payment options include solar loans and leasing:

• A solar loan lets you make payments over time with little to no money down, but the total cost typically ends up being higher than buying the panels outright.

• Leasing solar panels costs more than buying them or financing them with a solar loan, which reduces the lifetime savings. When leasing, you also aren't eligible for solar incentives or net metering, and you don't own the panels when the lease ends.

Solar panels vs. solar shingles

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Solar panels are the most popular choice for solar energy, but they are not the only option. If your budget allows, solar shingles cost $4 to $14 per watt and look like traditional roof shingles, blending in better with the surroundings and offering a sleeker alternative to standard solar panels.

Solar panels vs. solar roof shingles Factor Solar panels Solar roof shingles Average cost per watt
(installed) $2.50 – $4.50 $4.00 – $14.00 Pros

• Cheaper than solar shingles
• Adjustable options for maximum sunlight exposure
• 25 to 30+ year lifespan
• Clean, renewable energyIncreases home value

• Better looking than panels
• Suitable for roofs that can't support the weight of standard panels
• Clean, renewable energy
• Increases home value

Cons

• An eyesore to some
• Take up significant space
• Not suitable for all roofs
• Not easily transferrable

• Expensive
• Non-adjustable mount
• Lifespan not yet confirmed
• Less efficient than panels
• Only works with string inverter

Solar panel FAQs

Are solar panels worth it?

Solar panels are worth it for most homeowners, especially those dealing with high electricity rates. Solar panels can reduce or eliminate your electric bill for 25+ years. With a 6-to-10-year average payback period, this means 15+ years of free electricity—a reduced carbon footprint and significant long-term savings.

Solar panels may not be worth it if:

• Your payback period is longer than your solar system's estimated lifespan.

• Your roof type, pitch, or direction is not suitable for solar panels.

• Your monthly solar loan payment is higher than your electric bill.

• There are few state or local incentives in your area.

Use this formula to calculate your solar payback period:

Your system's total cost after any incentives ÷ the amount you'll save per year on electricity = payback period in years

Solar panel savings estimator - map

Do solar panels increase home value?

Solar panels increase home value in most cases. A home with well-maintained solar panels that significantly reduce or eliminate the electricity bill is an attractive selling point to potential buyers in most markets. The increase in value may be higher in areas with high electricity rates.

How long does it take to install solar panels?

Installing solar panels takes 1 to 3 days on average for the actual installation, depending on the system size, complexity, and weather. However, the entire process typically takes 1 to 3 months. This includes research, consultations, site evaluations, system design, permit applications, installation, and inspections.

How many solar panels do I need?

Most homes need 20 to 30 panels, depending on the type and size. The exact number of solar panels you need depends on your energy usage, available roof space, the amount of sunlight your roof receives, and the panel's wattage and efficiency. Solar panels range from 250 to 500 watts per panel.

How long do solar panels last?

Solar panels last 25 to 30 years on average with proper installation, depending on the location, climate, panel type and quality, and maintenance frequency. Other parts of your solar system, like the inverter that converts the sun's energy into usable electricity, typically need replacement before the solar panels.

A 25-year warranty is common for professionally installed solar panels.

Getting estimates from solar panel contractors

When searching for a solar panel installer near you, remember to:

• Look for contractors accredited by the North American Board of Certified Energy Practitioners (NABCEP) and members of relevant professional organizations, such as:

  • Solar Energy Industries Association (SEIA)

  • American Council on Renewable Energy (ACORE)

• Review their profiles and customer feedback on HomeGuide and Google.

• Ask for local references with contact information.

• Compare 3+ quotes from reputable solar companies detailing all parts of the installation, the number of watts per panel, the cost per watt, and any incentives or rebates factored into the estimate.

• Hire a licensed, bonded, and insured solar contractor who has been in business for 5+ years.

• Have a contract and warranty in hand before the installation begins.

• Beware of the extremely low prices as this can often indicate lack of experience or lower-quality work. Solar panels should last two or more decades so proper installation is essential.

Questions to ask a solar panel installer

Ask the following questions to help you select the best company for your solar panel installation:

• How long have you been in business?

• Are you accredited by the NABCEP?

• Are you a member of any other professional organizations?

• Is my home a good candidate for a solar panel system?

• What type of solar panels do you recommend for my home, and why?

• What size solar system do I need to eliminate my electricity bill?

• How do you calculate what size system I'll need?

• Is my roof in good enough condition to add solar panels?

• Is my electrical panel sufficient for a new solar panel system?

• Is there room to add more panels later if the energy needs change?

• Does the estimate include all necessary components, installation, permit and interconnection fees, and cleanup?

• What extra features are available, and what do they cost?

• How soon can you complete the installation?

• How long will the installation take, and should be home for it?

• Will installing solar panels void my roof warranty?

• Is this system eligible for any rebates or incentives, and will you help me obtain them?

• How long is the warranty, and what does it cover?

How we get this data

Using our proprietary cost database, in-depth research, and collaboration with industry experts, we deliver accurate, up-to-date pricing and insights you can trust, every time.

We’ve reviewed dozens of solar panel brands on the market and compiled this list of the top 400 W solar panels so that it is easier for you to choose the best 400 W panel for your needs.

Just a decade ago, 250- to 300-watt (W) solar panels were the standard size for most installations. But with rapid technological advancements, 400 W panels are becoming the most common (and preferred) solar panel rating. High-quality manufacturers, like Maxeon and QCells, have panels that are almost exclusively larger than 400 watts.

In contrast, other installers can only offer similar financing through solar leases, PPAs or third-party providers (such as Mosaic or Sunlight). Third-party loan providers can complicate the process, while opting for a loan or PPA will disqualify you from some of solar’s biggest benefits (additional property value, federal solar tax credit and local solar incentives).

Eligible homeowners enjoy 18 months of solar power before having to pay their first bill. When coupled with the federal solar investment tax credit (ITC), the initial energy savings can offset more than a third of the overall cost of a system before requiring a dollar down.

For that reason, Blue Raven Solar developed an innovative solar financing plan that offers in-house, flexible, zero-money-down options. The results speak for themselves, as Blue Raven Solar is now one of the fastest-growing solar companies in the nation and was recently acquired by SunPower. Its BluePower Plus+ plan (exclusive to Blue Raven) mimics the flexible structure of a lease while still providing the greatest benefits of owning your system.

We like Blue Raven Solar because it understands that, for most homeowners, the cost of solar presents the biggest barrier to entry.

SunPower’s biggest downside? Its high-efficiency panels are considerably more expensive than most of its competitors’ products. However, its powerful panels are workhorses that make up for the initial cost with more backend production (think about this like spending more money for a car that gets more miles per gallon).

If that weren’t enough, SunPower systems come packaged with products all manufactured in-house by its sister company, Maxeon. This means that your panels, solar cells, inverters, battery and EV chargers are designed to work together and are all covered under the same warranty.

SunPower earns its position as the top national installer on our list for a handful of reasons: It installs the most efficient solar technology on the residential market, offers the most expansive service area and backs its installations with a warranty well above the industry standard. All the while, SunPower pioneers sustainability efforts within the industry.

SunPower designs and installs industry-leading residential solar and storage solutions across all 50 states. With a storied history of innovation dating back to 1985, no other company on this list can match SunPower’s experience and expertise.

What is a 400-Watt Solar Panel?

The “watt” is a unit of power, denoting the amount of energy consumed or generated in an hour. For instance, a 50 watt LED bulb consumes 50 watts of power every hour. Similarly, a 400 watt solar panel generates up to 400 watts of power with every hour of direct sunshine. Therefore, a 400 W panel can ideally run 80 of the above-mentioned LED bulbs (50 W x 80 = 400W).

The polycrystalline solar panels from the older generations were far less efficient than today’s monocrystalline options, and could generate much less power in the same size. This is why 250 or 300 watts were the largest panel sizes until just a few years ago.

Speaking of solar panel sizes, most solar panels have 60 or 72 silicon cells in them. Any more than that and the panel weakens under its own weight. This makes the power rating so important, because all manufacturers have to maximize the power output in the available size limits.

Typically, 300 to 360 W panels (60 cells) are still used in residential applications, although panels pushing up to 400 to 500 W panels (72 cells) are also not uncommon. Commercial solar systems usually use panels between 450 and 650 watts.

What is the Best 400-Watt Solar Panel?

The last couple of decades have seen an incredible boom in solar panel manufacturing companies. The result of this is a wide variety of solar panel options to choose from. And with all the available options in the 400 W category, it is difficult to shortlist a few panels as the best options, let alone choosing a single panel as the best one.

All the solar panels we have selected have something unique in them — from aesthetics and innovative tech to cost and efficiency. The panel that is best for you will depend on several factors, and your own preferences.

However, if we had to choose just one “overall best 400 W panel,” we would award the title to Maxeon’s Maxeon 3 panel — just a note that Maxeon used to be SunPower and is not a sister company of SunPower. It offers the highest efficiency in its class, while also offering microinverters and some cutting-edge solar cell technology.

Compare 400-Watt Panels At A Glance

Manufacturer Superlative Price per Watt Features Warranty  Where to Buy Sunpower/Maxeon 3 Best overall $4.25/W High efficiency,

Integrated microinverter,

High durability

40-year product warranty, 25-year performance guarantee Through SunPower/authorized installers Silfab Elite SIL-410 BG Best aesthetics $3.90 – $4.50/W Sleek design,

High efficiency,
Made in USA

25-year product warranty,

30-year performance guarantee

Through authorized installers Q Cells Q. Peak Duo BLK ML-G10+ Best American-made $3.50 – $3.90/W High efficiency,
Made in USA,12 Busbar technology 25-year product warranty,

25-year performance guarantee

Through authorized installers Mission Solar MSE PERC 60 BLK Most affordable $3.00 – $3.40/W Affordable pricing,
Made in USA 12-year product warranty,

25-year performance guarantee

Through authorized installers Canadian Solar HiKu dual cell PERC CS3N400 Most value for money $3.00 – $3.80/W High efficiency,
Reasonable pricing,Dual cell technology 10-year product warranty,
25-year performance warranty Through authorized installers Solaria PowerXT Pure Black Best warranty $2.75 – $3.25 Sleek, all black aesthetics,

High efficiency,

no busbar design

30-year warranty on power, parts and labor Through partner installers EcoFlow Foldable 400W solar panel Best portable $1,199 (system price not applicable) Highly portable,
High efficiency,High durability 12 months Amazon

Sunpower/Maxeon Maxeon 3 Series – Best Overall

Maxeon’s state-of-the-art 3 series residential solar panel offers an impressive efficiency of 22.7%, which is the highest in the industry. It houses larger mono-Si solar cells and comes with integrated microinverters supplied by the industry-leader Enphase.

• Price: $4.25/W
• Dimensions: 71.3 x 41.2 x 1.57 in
• Weight: 46.7 lbs.
• Where to buy: Through SunPower or other authorized installers

Pros and Cons of SunPower A400-G-AC Residential Series

Pros:

• High efficiency
• Integrated microinverters
• Industry-leading warranty

Cons:

• Expensive

Read our review of Maxeon solar panels

Silfab Elite SIL-410 BG – Best Aesthetics

Labeled by the maker as “America’s most beautiful panel,” the Elite SIL series comes with a sleek, all-black look, thin profile and superb efficiency numbers. The panel’s innovative conductive backsheet and integrated cell design make it stand out in terms of performance as well as looks.

• Price: $3.90 – $4.50/W
• Dimensions: 73.4 x 40.5 x 1.4 in
• Weight: 45.8 lbs.
• Where to buy: Through authorized Silfab installers

Pros and Cons of Silfab Elite SIL-410 BG

Pros:

• High efficiency
• Exceptional aesthetics
• Excellent warranty
• Made in the U.S.A.

Cons:

• Slightly expensive

Q Cells Q. Peak Duo BLK ML-G10+ – Best American Made

Q Cells is one of the oldest and most respected solar power companies and one that has ramped up production in the U.S. at a gigantic scale. This large-scale production allows Q Cells to offer high-quality, feature-packed panels at reasonable costs, and the Q. Peak Duo is no exception.

• Price: $3.50 – $3.90/W
• Dimensions: 74.0 x 41.1 x 1.26 in
• Weight: 48.5 lbs.
• Where to buy: Through authorized Hanwha Q Cells installers — Momentum Solar, Palmetto Solar and Trinity Solar.

Pros and Cons of Q Cells Q. Peak Duo BLK ML-G10+

Pros:

• High efficiency
• Excellent warranty
• Highly reliable brand
• Made in the U.S.A.

Cons:

• Q Cells went bankrupt in 2012, but was then brought out by The Hanwah Group — a large South Korean business conglomerate. The company has been stable since, but it’s worth calling out.

Read our review of Q Cells solar panels.

Mission Solar MSE PERC 60 BLK – Most Affordable

Texas-based Mission Solar has quickly risen to be one of the most popular local solar companies. Its MSE series offers high-quality PERC modules at a reasonable price tag, which also come with decent efficiency and positive power tolerance of 0 to 3%.

• Price: $3.00 – $3.40/W
• Dimensions: 65.98 x 39.68 x 1.38 in
• Weight: 44 lbs.
• Where to buy: Through Mission Solar or authorized installers

Pros and Cons of Mission Solar MSE PERC 60 BLK

Pros:

• Low cost per watt
• Made in the U.S.A.

Cons:

• Not as reputed as others on this list

Read our review of Mission Solar panels.

Canadian Solar HiKu dual cell PERC CS3N400 – Most Value for Money

Canadian Solar is one of the oldest solar module manufacturing companies. Its HiKu series is popular, and the dual cell PERC module brings all the essential modern tech to a reasonable price slab.

• Price: $3.00 – $3.80/W
• Dimensions: 76.4 x 41.3 x 1.38 in
• Weight: 49.6 lbs.
• Where to buy: Through Canadian Solar or authorized installers — Momentum solar, Blue Raven Solar

Pros and Cons of Canadian Solar HiKu dual cell PERC CS3N400

Pros:

• High efficiency PERC technology
• Reliable brand
• Low LID losses

Cons:

• Ordinary design

Solaria PowerXT Pure Black – Best Warranty

Solaria’s proprietary Pure Black technology enhances both solar panel aesthetics and performance. The PowerXT panel crosses the 20% efficiency barrier and comes with a 30-year warranty. Solaria was recently purchased by Maxeon, so the warranty coverage you get for those 30 years now rivals the best in the business.

• Price: $2.75 – $3.25
• Dimensions: 64.72 x 47.4 x 1.57 in
• Weight: 46 lbs.
• Where to buy: Through Solaria’s partner installers

Pros and Cons of Solaria PowerXT Pure Black

Pros:

• High efficiency
• Solder-less design
• Exceptional 30-year warranty
• Low PID losses
• Innovative, no busbar design

Cons:

• Limited buying options

EcoFlow Foldable 400 W Solar Panel – Best Portable

A highly popular name in portable solar products, EcoFlow is the only reputed brand that offers a single, foldable 400 W solar panel (unlike Renogy’s multi-solar-panel kit). The panel impresses not only with its portability but also with the high efficiency and thoughtful design, making it perfect for DIY and off-grid installs.

• Price: $1,199 (per-watt system pricing not applicable)
• Dimensions: 42.0 x 94.1 x 1.0 in
• Weight: 35.3 lbs.
• Where to buy: Through Amazon or EcoFlow’s official website

Pros and Cons of EcoFlow Foldable 400 W Solar Panel

Pros:

• Foldable and lightweight design
• High efficiency
• Integrated and adjustable mounting kickstand
• Highly durable, glass-free structure
• Plug-and-play design

Cons:

• Unimpressive warranty
• Expensive

How Much Do 400-Watt Solar Panels Cost?

The easy answer: it depends on the brand of the 400W solar panel.

Modern solar panels that share the same power rating may not share the same features and, consequently, the same pricing. As expected, the more innovative and technologically-advanced solar panels typically cost more than simpler models.

The cost of solar panels rated for 400 W output can be anywhere between $3 and $5 per watt installed. Remember that this is the price of the entire solar power system, installed using a number of 400 W mono solar panels together.

We cannot state the price of an individual 400 W panel, since it is generally difficult to source only the solar panels (unless you are an authorized installer yourself, in which case you likely wouldn’t need to read this article). However, the average price per watt in the U.S. for PV panels is $3.33, using data from a variety of sources, so that puts the average cost of a single 400-watt panel at around $1,332.

Like any other product, it’s important to remember that cost alone should not be the deciding factor when choosing 400 W panels. Oftentimes a more costly panel can save you a lot more money over its lifespan. Or, a panel with stronger warranties can offer more reliability than a cheaper panel with short warranties.

The best way to choose a 400 W solar panel is to narrow down your needs and preferences and choose the product that has the optimum balance between cost, features, efficiency and warranty.

How Much Energy Will a 400-Watt Solar Panel Produce?

While most homeowners will naturally want to know how much solar energy each 400-watt panel they install on their homes will produce, the answer is a bit complicated.

The rating on your PV module in wattage tells you the maximum amount of energy it can generate with full, intense sunlight. This measurement of power output is called the Standard Test Condition (STC).

However, in reality, there are many factors that affect the panel’s efficiency and power production. Some of the factors that affect your production are shown below:

• The direction your panels face
• The intensity of the sunlight that hits the panels
• The hours of daylight in your area
• The weather, including the average number of cloudy days per year
• Shading on your property from trees or nearby buildings
• The brand of the panel you choose and its maximum efficiency
• The age of your panel, as they lose efficiency over time

For a baseline production, you can use the calculation below, but remember that this estimate can change drastically based on the factors above:

Your Daily Watt-Hours per Panel = [average hours of sunlight] x [solar panel wattage] x [75% maximum power production to account for changing weather conditions and lower sun intensity in the morning and afternoon]

Your Daily Kilowatt-Hours (kWh) per Panel = [your daily watt-hours] / 1,000

If we assume that your area receives six hours of sunlight every day, we can use the above equation to calculate how much power each 400-watt panel on your property will produce on a daily basis.

[6 hours of sunlight] x [400 watts] x 75% = 1,800 watts per day

[1,800 watts per day] / 1,000 = 1.8 kWh per day

Remember, this should be considered as maximum production, and the factors mentioned above can bring this number down significantly. If we assume maximum production, you’re looking at 1.8 kWh of energy production every day, which equates to 657 kWh per year per 400-watt panel.

How Many 400-Watt Solar Panels Do I Need to Power My Home?

Based on our above calculation of annual energy production from a 400 W solar panel, we can calculate how many panels your home will need.

For example, if your home consumes the national average of 10,572 kWh per year, you’d need 13 400-watt panels to power your home. The calculation below explains why.

[10,572 kWh of energy needed] / [876 kWh of production per panel] = 12.06 panels, which gets rounded up to 13 panels

Don’t feel like whipping out your calculator? No worries. You can use our solar calculator to find out how many solar panels you need to power your home.

Keep in mind that solar panels alone cannot power a home. You will need other supporting components — such as an inverter, branch connectors, tray cables, z brackets and more. If you want to store your solar energy for later, you’ll also need solar batteries and an MPPT solar charge controller.

Maybe you’re not looking to power your entire house and are instead wondering what a single 400 W panel can run. Thankfully, this is simpler to find out. The “watt” rating denotes not only the power generated, but can also denote power consumption rating on appliances.

All you need to do is check the rating on an appliance and make sure it is lower than that of your solar panel. In this case, anything that consumes less than 400 W of power can operate on a 400 W solar panel. A few examples of this are listed in a table below:

APPLIANCE/HOUSEHOLD ITEM RUNNING OR RATED WATTS REQUIRED TO RUN Phone Charger 10 watts CFL Light Bulb 18 watts Ceiling Fan 60 watts Standard 60W Incandescent Light Bulb 60 watts DVD Player 100 watts Mini-Fridge 100 watts Home Speaker System 100 watts Box Fan or Floor Fan 100 watts Hair Straightener 120 watts Laptop Power Supply 125 watts Electric Can Opener 170 watts Gaming Console 180 watts Vacuum Cleaner 200 watts Rice Cooker 200 watts Heated Blanket 200 watts Up to 56” LCD TV 225 watts Paper Shredder 225 watts TV 230 watts PC (Non-Gaming) 240 watts Small Dehumidifier 250 watts Computer Monitor 250 watts Crockpot 250 watts Projector 280 watts Whole-House Exhaust Fan 350 watts Blender 360 watts Central AC Fan Only 370 watts

Roof Space Requirements for 400-Watt Solar Panels

When you are installing a complete solar power system, the roof space required for your system depends more on the total system size than the individual panel size.

As a thumb rule, every kilowatt (kW) of a solar power system requires about 75 square feet of space. Therefore, a typical 11 kW system may need around 825 sq. ft. of roof space. But if we had to calculate using 400 W panels only, here’s how we could do it:

A typical 400 W solar panel is about 75 x 45 inches in dimensions, which is about 25 square feet. An 11 kW system will need about 13 solar panels rated 400 W. This gives us,

25 sq. ft./panel x 13 panels = 325 sq. ft.

Add another 20% to this to account for the space required for safe racking, combiner boxes, wiring and the space left between panel strings to avoid shading. Thus we have:

325 x 120% = 390 sq. ft.

It is important to remember that these are basic calculations and general thumb rules which may or may not apply in every case. Based on the complexity of your roof and other factors encountered in solar installations, your system may need more, or sometimes less space. That’s why it’s best to connect with an experienced solar installer to figure out your solar needs.

Methodology: How We Ranked the Top 5 Best 400-Watt Solar Panels

To stay impartial, our solar experts evaluate hundreds of solar manufacturers in our database based on the same range of criteria and assign scores to each category. The main factors we assessed to find the best 400-Watt solar panels include:

• Cost and ease of purchase (20%): Cost is typically the biggest deciding factor for homeowners going solar. Obviously, solar panels at 400W are going to be more expensive than 250W or 350W panels because they’re stronger, but we still look for companies that offer reasonable prices for the quality. Companies with the most transparent, economical and practical financing options also scored highest in this category.
• Warranty coverage (15%): Solar panel manufacturers offering longer, more comprehensive warranties performed better in this category.
• Experience (15%): Companies with less than 10 years of solar manufacturing experience are docked in this category. Most with less than five were deemed not eligible for ranking.
• Availability (15%): Solar panel brands that are available to a larger number of customers scored higher in this category.
• Reputation (15%): We analyze reviews and trends on Google reviews, the Better Business Bureau (BBB) and similar review sites and assign scores accordingly.
• Solar services (20%): Manufacturers with more comprehensive service offerings perform better in this category. We also assess the quality of the products that the provider installs.

For a more in-depth look at our methodology, you can visit our solar rankings page.

 

The cost information presented in this article is derived from a comprehensive analysis, incorporating data from multiple industry sources. The average cost per watt per state was calculated based on figures from Consumer Affairs, Energy Sage, and Berkeley Lab’s Electricity Markets & Policy Department. Additionally, monthly energy consumption and the average monthly cost of electricity were sourced from the U.S. Energy Information Administration, ensuring a well-rounded and accurate representation of the information presented.