3 Types of Solar Panels (Which Is Right for You?)
By Leonardo David /
In this EcoWatch guide on 400-watt solar panels, you’ll learn:
Each product and or company featured here has been independently selected by the writer. You can learn more about our review methodology here. If you make a purchase using the links included, we may earn commission.
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.
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.
Best Overall – SunPower A400-G-AC Residential Series
Best Aesthetics – Silfab Elite SIL-410 BG
Best American Made – Q cells Q. Peak Duo BLK ML-G10+
Most Affordable – Mission Solar MSE 420SX6W
Most Value for Money – Canadian Solar HiKu dual cell PERC CS3N400
Best Warranty – Solaria PowerXT Pure Black
Best Portable – Ecoflow Foldable 400W solar panel
Nationwide Service
Average cost
Pros
Cons
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.
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.
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’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).
EcoWatch Rating |
---|
Better Business Bureau (BBB) Rating |
Year Founded |
Average Cost ($-$$$$$) |
Solar Services |
Brands of Solar Equipment Offered |
Warranty Coverage |
5 |
A+ |
1985 |
$$$$ |
Solar Panels, Solar Batteries, EV Chargers, System Monitoring |
SunPower Panels |
25-year all-inclusive warranty |
Regional Service
Average cost
Pros
Cons
We like Blue Raven Solar because it understands that, for most homeowners, the cost of solar presents the biggest barrier to entry.
For that reason, Blue Raven Solar developed an innovative solar financing plan that offers in-house, flexible, zero-money-down options. The results speak for themselves, as Blue Raven Solar is now one of the fastest-growing solar companies in the nation and was recently acquired by SunPower. Its BluePower Plus+ plan (exclusive to Blue Raven) mimics the flexible structure of a lease while still providing the greatest benefits of owning your system.
Eligible homeowners enjoy 18 months of solar power before having to pay their first bill. When coupled with the federal solar investment tax credit (ITC), the initial energy savings can offset more than a third of the overall cost of a system before requiring a dollar down.
In contrast, other installers can only offer similar financing through solar leases, PPAs or third-party providers (such as Mosaic or Sunlight). Third-party loan providers can complicate the process, while opting for a loan or PPA will disqualify you from some of solar’s biggest benefits (additional property value, federal solar tax credit and local solar incentives).
EcoWatch Rating |
---|
Better Business Bureau (BBB) Rating |
Year Founded |
Average Cost ($-$$$$$) |
Solar Services |
Brands of Solar Equipment Offered |
Warranty Coverage |
4.5 |
A+ |
2014 |
$$ |
Solar Panels, System Monitoring |
Trina Solar, Canadian Solar, SolarEdge, Silfab, SunPower |
25-year manufacturer warranty; 10-year workmanship warranty, 2-year production guarantee |
Regional Service
Average cost
Pros
Cons
ADT Solar sets the industry standard for warranty coverage by including a multifaceted guarantee, making it one of the top installers for homeowners who want added peace of mind.
Its warranty coverage includes all of the following for 25 years:
Though in recent years other solar companies have started to offer similar guarantees, ADT Solar has been at it since 2008, performing over 30,000 installations across the country.
EcoWatch Rating |
---|
Better Business Bureau (BBB) Rating |
Year Founded |
Average Cost ($-$$$$$) |
Solar Services |
Brands of Solar Equipment Offered |
Warranty Coverage |
4 |
A- |
2008 |
$$$ |
Solar Panels, Solar Batteries, EV Chargers, Energy-Efficiency Upgrades |
Silfab, Panasonic and others depending on location |
25-year all-inclusive warranty |
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 and 400 to 500 W panels (72 cells) are used in commercial applications. However, this is swiftly changing, as people are regularly installing 400+ W panels on homes, cabins and even RVs.
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 SunPower’s A400-G-AC Series Residential panel. It offers the highest efficiency in its class, while also offering microinverters and some cutting-edge solar cell technology.
Manufacturer | Superlative | Price per Watt | Features | Warranty | Where to Buy |
Sunpower A400-G-AC Series Residential | Best overall | $3.25/W | High efficiency, Integrated microinverter, High durability | 25-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, | 25-year product warranty, 30-year performance guarantee | Through authorized installers |
Q Cells Q. Peak Duo BLK ML-G10+ | Best American-made | $3.10 – $3.50/W | High efficiency, Made in USA,12 Busbar technology | 25-year product warranty, 25-year performance guarantee | Through authorized installers |
Mission Solar MSE 420SX6W | Most affordable | $2.25 – $2.60/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 | $2.45 – $3.00/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’s state-of-the-art A series residential solar panel offers an impressive efficiency of 21.5%. It houses larger mono-Si solar cells and comes with integrated microinverters supplied by the industry-leader Enphase.
Pros:
Cons:
Read our review of SunPower solar panels
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.
Pros:
Cons:
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.
Pros:
Cons:
Read our review of Q Cells solar panels.
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%.
Pros:
Cons:
Read our review of Mission Solar panels.
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.
Pros:
Cons:
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 that is yet unsurpassed.
Pros:
Cons:
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.
Pros:
Cons:
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 $2 and $4 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).
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.
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:
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.
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 10,715 kWh per year, you’d need seventeen 400-watt panels to power your home. The calculation below explains why.
[10,715 kWh of energy needed] / [876 kWh of production per panel] = 16.30 panels, which gets rounded up to 17 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 |
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 6 kW system may need around 450 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. A 6 kW system will need about 15 solar panels rated 400 W. This gives us,
25 sq. ft./panel x 15 panels = 375 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:
375 x 120% = 450 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.
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:
For a more in-depth look at our methodology, you can visit our solar rankings page.
Unlike solar panel calculations, battery calculations are a bit more tricky. In order to find out the size of battery needed, add up the watt-hours of all your appliances that you will operate in the absence of sunshine, and choose a battery based on this number.
For example, if you use lights, TV, fridge and a laptop in the evening and their energy ratings add up to 2 kWh, you can choose a battery with 2 kWh capacity. If you are using a battery bank, we recommend buying deep cycle lithium batteries.
A 400 W solar panel system, as mentioned above, can run any appliance(s) which consumes less than 400 watts of power. However, besides wattage, you may also need to match the voltage. For example, you cannot connect a 400 W panel with a voltage at open circuit (Voc) of 48 to a 12 volt appliance directly.
While different solar panels have different dimensions, a typical 400 W monocrystalline solar panel may take anywhere between 20 and 30 sq. ft. of space.
The cost of a 400 W solar panel varies based on factors such as types of cells, efficiency, features, etc. However, a system of 400 W panels may cost between $2 and $4 per watt of installed capacity.
A single 400 watt solar panel is insufficient in powering an entire home, but it can power small systems including a few appliances under the 400 W mark. To power an entire house, however, you will need multiple 400 W solar panels.
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