Table of Contents
- SunPower SPR-X21-345
- SunPower 50 W and 110 W Flex
- Winaico 330W to 340 W WSP-MX PERC
- Jinko Solar
- Trina Solar
- LG Neon R 370 W
- Hanwha Q CELLS Q.PEAK DUO BLK-G6+
- Silfab Solar
- Panasonic 340N HIT Module
- Mission Solar 375 W
- Key Considerations when Buying Solar Panels
- Solar Panel Efficiency
- Solar Panel Efficiency in Hot Climates and Lifelong Solar Panel Efficiency
- Best Solar Panels for Partially Shady Areas
- Best Solar Panels for Wind Prone Areas
- Cost per Watt
- Warranty and Service Record
- Ethical Solar Panels – Eco-Friendly, Low-Toxicity Solar Panels
- Solar Patio?
There are currently hundreds of brands offering solar panels for sale in the US, and your needs will differ wildly depending on where you live, how hot it is, the amount of space you have, and other factors. Here, I offer some quick tips on how to choose the best solar panels for your needs and my top picks for the best solar panels for 2021. If you do end up going the solar panel route, you’d do well to look into our list of the best lithium-ion batteries to store all that power too.
Curious about how we rate products? Click here to view our methodology, which at its core, is about voting with our dollars to fight climate change.
SunPower SPR-X21-345
Highlights: Highest quality and efficiency solar panels from one of the more ethical companies around.
Note: If you consider yourself a bit more of a DIYer, your best bet may be one of the LG Panels through GoGreenSolar. While SunPower wins high marks for the quality of their solar panels from the team, their process tends to be dependent on having a vendor in your area and setting up consultations to have the panels installed for you. If you want beginning-to-end support in switching to solar power, SunPower should be your go-to. If you already know what you want and what you’re doing, a direct-to-consumer purchase like the above may better fit your needs.
SunPower offer both the best solar panel specifications, including the highest efficiency, great temperature coefficient, and minimal degradation, and are also pretty ethical to boot. They also offer an industry-leading warranty.
SunPower’s SPR-X21-345 panel has an impressive temperature coefficient of -0.3%, just a bit higher than Panasonic’s leading -0.26% for the HIT panels. SunPower has Panasonic beat for overall efficiency though, at 22.8% for their best panels.
The 25-year performance warranty offered by SunPower demonstrates the company’s confidence in their solar panels. Instead of the typical 80% performance warranty offered by most companies, SunPower are committed to a whopping 92% after 25 years. That means they are confident their panels will still be performing at almost full bore in more than two decades’ time.
SunPower panels have earned a bit of a reputation as being out of reach for most customers, pricewise. However, if you shop around and get a good installation team, your solar system using SunPower panels could cost you only marginally more than a much less efficient array.
All in all, if you have limited space and want the best solar panels available, from a company in the top 10 for ethical practices, SunPower is hard to beat. We also like them for their Flex range, ideal for smaller spaces such as RVs and mobile homes.
SunPower 50 W and 110 W Flex
Highlights: Best solar panels for RVs, boats, mobile homes and smaller, unusual spaces.
If you’re tight on space and looking for the most efficient, high-quality solar panels around, consider the SunPower Flex series. These solar panels are ideal for RVs, boat, mobile homes, and other small areas where you need to work within tight space constraints.
The SunPower 50 W and 110 W Flex panels have a low profile and can bend up to 30 degrees, meaning it’s easier to get the right configuration even if you have to wrap them around a curved surface.
The panels are lightweight, great little performers in low light conditions, and are durable, easy to install, and adaptable. The Flex 50 W cost under a hundred bucks, making these a great first step into solar power.
As you might expect, given their flexibility, these panels cost quite a bit more, Watt for Watt, than the regular SunPower panels and other standard solar panels. If you need something robust that can perform great in harsh conditions, SunPower’s Flex panels are arguably your best option.
Winaico 330W to 340 W WSP-MX PERC
Highlights: Wind-resistant solar panels from one of the more ethical solar energy companies.
Nobody wants to invest a cool $20k on solar panels only to have them wrenched from the roof or mangled beyond recognition in a wind-storm. So, if you live in a particularly wind-prone area and are considering a solar array, look for panels with extremely strong framing and a reputation for standing up to a good whipping wind.
Winaico are a great choice for such conditions. Their panels were some of the first to pass an industry leading hail test, sport the HeatCap which helps protect against micro-cracks that impact performance, and they have an extremely tough and durable design with water drainage channels to help reduce dirt and dust accumulation.
This family-run Taiwanese company is unique among competitors in that they don’t distribute panels through wholesalers. Instead, they provide panels direct to installers, solar technicians, and project managers, which can both help to reduce your costs and ensure a more direct relationship between the company and the end user.
Winaico solar panels are tested to German TUV standards and were recently awarded a 2018 Top PV brand seal in Germany for quality and longevity. The company integrated PERC (passive emitter rear cell) technology earlier than most companies and makes very efficient monocrystalline cells, including the 2019 series 330W to 340 W WSP-MX PERC.
The WSP-MX series uses high-grade P-type mono PERC cells with 5 busbars to deliver up to 19.4% efficiency, with a temperature coefficient of -0.38%. They incorporate the familiar high-strength Winaico frames and drainage features, come with a 15-year product warranty and a 25-year performance warranty. The average linear degradation is 0.7% annually, with a performance warranty guaranteeing 80.2% at the 25-year mark.
Winaico claim to have had only 16 recorded panel failures across more than 250,000 panels distributed in Australia over the last 7 years.
Winaico also advocate for Extended Producer Responsibility (EPR) and strive to reduce energy and water usage throughout the manufacturing process. They pay attention to environmental protection across the whole life-cycle of the solar panel and work with recycling partners to help ensure the products are recycled in compliance with the WEEE directive (Waste of Electrical and Electronic Equipment). Winaico’s environmental management system is also certified to ISO 14001 and they put out an annual Corporate Social Responsibility report.
Jinko Solar
Highlights: Most ethical solar panel company on the Solar Scorecard and good for hotter areas.
Jinko Solar are one of the world’s largest solar panel manufacturers and have been around since 2006. They manufacture panels in China and Malaysia and are a newer name in the US market. They make both residential and commercial solar energy systems, have efficiency ratings ranging between 15.57% and 19.88%, and temperature coefficients as low as -0.36%.
Jinko aren’t as generous as some competitors such as SunPower, Panasonic, Trina, and LG, offering only a 12-year warranty against manufacturing defects. They are, however, a leading voice in the push to reduce lifetime degradation of the panels.
The Tiger Mono-Facial 450-470 Watt solar panels are up to 20.93% efficient, with 0.4% linear degradation, meaning a guaranteed power performance of 87.4% at the 30 year mark.
They have a -0.34% temperature coefficient, which isn’t as good as SunPower’s models but still beats many competitors. These panels have half-cell technology, offering 78 cells twice over. This makes the Tiger panels a great choice for low-light environments, e.g. early morning, dusk, and with cloud cover, as well as for anyone looking to really maximize output in a smaller space.
Trina Solar
Highlights: Longstanding, ethical, and reputable solar panel company making efficient and durable solar modules.
Trina Solar Energy was founded in 1997 and manufactures all panels in China. They were narrowly beaten by Jinko Solar for top spot for ethical solar panel producer on the Solar Scorecard for 2018/19, so if you’re looking for a good mixture of solid ethics, efficiency, availability, and price, give Trina a go.
The Trina solar range includes models that are 16.2% to 19.9% efficient, with some panels boasting a temperature coefficient of -0.38%.
Trina only offer a standard 10-year warranty, however, but they’ve installed so many solar panels worldwide that you can be reasonably confident they’ll make good on that warranty in the rare event you need to call them on it.
One of the best options available from Trina currently is their DUOMAX TWIN series, that comes with a 30-year power warranty. This is arguably the best PID-resistant, durable dual-glass bifacial module and is highly robust against extreme weather.
LG Neon R 370 W
Highlights: High efficiency and quality, good performance warranty, but a little pricier than some other options.
LG White on Black Mono 370W 60 Cell solar panels are an improved version of the LG Neon 360W panels I previously recommended here. The newer, high-efficiency, premium-quality solar panels have 21.4% efficiency and an impressive degradation loss of just 0.3% per year (that’s significantly less than most panels!). These LG solar panels have a performance warranty of 90.8% efficiency after 25 years, a workmanship warranty of 25 years, and a fantastic temperature coefficient of -0.003% (which pretty much little loss of performance within most reasonable temperature changes).
Most companies only offer a workmanship warranty for 10 years, but LG extends its warranty to 25 years. The design is also very streamline, with a back contact cell structure effectively hiding electrodes.
At a cost of around $621 per panel, these work out to around $1.68 per Watt, which is double that of Mission Solar’s 375 W panels and more than Panasonic’s better-performing panels. So, if you’re going to choose LG it will be because of their solid reputation for quality and customer support, and the hyper-efficiency of the panels, not price.
Thanks to their impressive efficiency, these LG panels provide more output from a 60-cell panel than a standard 72-cell panel. If you are tight on space, with room for just 10 or fewer panels on your roof, you’re going to need the best quality solar panels, which means either LG or SunPower.
Hanwha Q CELLS Q.PEAK DUO BLK-G6+
Highlights: High-quality solar panels made in the US with a solid warranty and performance warranty and half-cell technology good for shadier spots.
The Q Peak DUO Black-G6+ is manufactured with larger cells for 6% more power and can provide up to 355 W. These panels are made in Georgia, US, have a 12-year product warranty and a 25-year performance warranty, with a max 0.54% degradation per year. This means a guaranteed 85% of initial performance up to 25 years. They stand up well to high winds and have an efficiency rate up to 20.1%.
The temperature coefficient of these panels is around -0.36%, which is a decent bit higher than for Panasonic and SunPower (-0.26% and -0.29% respectively). They do have half-cell technology though, meaning they’re a good option for partially shady areas. They’re also certified for high snow and wind loads.
These solar panels are made by one of the world’s largest and well-regarded photovoltaic manufacturers. Hanwha Group is a FORTUNE Global 500 firm and a Top 8 business enterprise in South Korea. The company has been around since the 1950s, started making solar panels in 2011, and is a Tier 1 solar panel manufacturer. Hanwha bought out the German company Q-Cells in 2012 and quickly became one of the best brands of solar panels around.
Interestingly, Hanwha Q-Cells are currently engage in legal action against Jinko Solar, REC Group and Longi alleging patent infringements.
Silfab Solar
Highlights: Efficient solar panels with a sleek black look and potential tax credits through the Buy America Act.
Silfab is a Canada-based company manufacturing monocrystalline and bifacial solar panels in North America for sale worldwide. Founded in 2010, Silfab is a popular brand for both residential and commercial solar arrays, offering value for money and a home-grown product for those of us who like to buy more locally. Indeed, some Silfab solar panels comply with the Buy American Act (BAA), which may open up additional incentives for commercial and residential solar projects.
Silfab’s panels range in efficiency from 17.8% to 20%, with temperature coefficients ranging from -0.42% to -0.36% (it’s -0.38% for the SLG-330M panel and -0.377% for the SI-330 BL.
For the SIL-330 BL, efficiency ranges from 18.14% to 19.4%, with a performance guarantee of ≥ 90% by the end of the 12th year, ≥ 82% by end of 25th year, and ≥ 80% by end of 30th year. That’s an annual degradation rate of about 0.65%. These panels now come with a 25-year product warranty and a 30-year performance warranty.
The SIL-330 BL BC Series 126 cell module is made in Washington State and features back-contact metal wrap through solar cells and an integrated conductive backsheet, enhancing performance and creating a sleek black look.
Panasonic 340N HIT Module
Highlights: Efficient, high quality solar panels with 25-year performance guarantee – a top choice for hotter climates!
Panasonic make super high-quality solar panels that are highly efficient and a superior choice for hot climates, thanks to their very low 0.26% temperature coefficient. In 2019, Panasonic released updates to its N330E/N325E AC Modules, creating smart-grid ready modules for residential users. These high efficiency, high output solar modules combine HIT® solar panels with the ‘smart’ Enphase IQ 7X Microinverters.
Panasonic have a solid reputation for excellence in manufacturing and customer service, provide a 25-year warranty, including a solid performance warranty, and are all-round a great choice for a home solar energy system.
If you need a little more juice to your panel, check out the new Panasonic 340N HIT Module, providing the same efficient HIT technology and even greater performance in hotter and low light conditions, but with a smaller footprint than similar products. These panels are 20.3% efficient, have a temperature coefficient of just 0.258% (one of the lowest in the world), and are backed by a TripleGuard warranty. This warranty guarantees minimum power output of 90.76% after 25 years and covers performance, parts, and labor for 25 years, assuming installation by an authorized installer.
Mission Solar 375 W
Highlights: Made-in-America solar panels, great for larger rooftops in the northern states, and totally affordable!
If space is no problem and you don’t have too many very hot days where you live, consider buying solar panels made in the US by Mission Solar. Their inexpensive monocrystalline 375 W panels cost around $275 (or 73 cents per Watt), have a 25-year performance warranty and 10-year workmanship warranty, and are made in San Antonio, Texas. Even some of the cheapest imported solar panels cost 70 cents per Watt or more and come with a largely unknown environmental price tag to boot.
Mission Solar’s 375 W panels offer 18.89% efficiency across 72 cells (or 310 W across 60 cells), with a -0.375% temperature coefficient and a degradation rate of -0.7% per year. Ironically, then, they’re not your best option for efficient solar panels in Texas, but would likely work well in Washington State, Maine, or Wisconsin, or Alaska.
Key Considerations when Buying Solar Panels
Solar Panel Efficiency
Solar panel efficiency is often touted as the be all and end all when choosing a solar array. The truth is, though, that unless you’re very tight on space, you may be better off going for a slightly cheaper model of solar panel that is a little less efficient and just takes up a dash more space. After all, a 300-Watt panel will still produce 300 Watts, regardless of how big or small it is. If you have a small roof space, however, choosing more efficient solar panels gets you the maximal solar output for your space.
Understanding solar panel efficiency can be a bit confusing, so let’s break it down. Imagine two solar panels that are the same size. One is 20% efficient and the other is 16% efficient. That’s a difference of 4% between the two, which is a quarter (or 25%) of the lower efficiency solar panel. So, under the same conditions, the more efficient panel will produce 25% more electricity than the less efficient panel.
Need another example? Take two panels that are 21% efficient and 14% efficient. That’s a 7% difference in efficiency, or half of the lower efficiency panel’s efficiency rating. This means that the more efficient panel produces 50% more kilowatt hours given the same conditions.
In a small space, a25-50% improvement in efficiency can really make a difference to your electricity bill!
So, which solar panels are most efficient? The top 3 solar panels for efficiency are:
- SunPower – SPR-X22-370-D-AC, a 370 W panel with 22.7% efficiency
- LG – Neon R Ace LG375A1C-V5, a 375 W panel with 21.7% efficiency
- REC Group – REC Alpha Series 380AA, a 380 W panel with 21.7% efficiency
Remember, though, that these efficiencies are at ideal conditions, for the first few years of a panel’s life. As panels get older, or at much hotter temperatures, or in partial shade, different panels fare better or worse than others.
Solar Panel Efficiency in Hot Climates and Lifelong Solar Panel Efficiency
If you live in a more northern state, or are way up in Alaska, you don’t need to pay much, if any, attention to temperature coefficients. For anyone in the south, though, this may be a major factor in your decision-making process.
Multi and mono cell solar panels tend to lose 0.38% to 0.42% efficiency for every degree Celsius increase. This drop in efficiency is called the temperature coefficient. On very hot days with little wind, your solar panels may well produce 20% less electricity than under ideal conditions.
Most solar panels are rated for efficiency based on a temperature of 25 degrees Celsius or 77 degrees Fahrenheit. So, if your solar panels has a temperature coefficient of -0.3%, the panel’s electricity output falls by 0.3% with a one degree increase in temperature to 26 degrees Celsius. If it’s 35 degrees Celsius (95 degrees Fahrenheit) on your roof, that panel will produce 3% less electricity.
The temperature of a flat black roof on a spring day can easily top 25 degrees Celsius, and in summer months the drop in electricity output can be significant with less efficient models. If this sounds like your situation, you’ll want a solar array with a low temperature coefficient.
Panasonic’s N-type silicon cells are great performers at high temperatures, making them a good option for more southern states. They lose less than 0.26% efficiency per degree Celsius increase, which is the best temperature coefficient around today. These panels have an efficiency rating up to 20%, making Panasonic HIT a great choice for residential rooftops and large-scale commercial solar arrays.
Other solar panels that lose little efficiency at high temperatures include the REC Group and Solartech Universal panels, with a temperature coefficient of -0.26% (like Panasonic’s), SunPower (-0.29% temp. coefficient), and LG (-0.3%).
Premium N-type solar panels cost a little more per Watt but are vastly more efficient than other models. They are also far better performers in hot climates, and they suffer little light-induced degradation (LID), meaning that they remain efficient even after a couple of decades.
Some of the best performance warranties in the industry come courtesy of the following three companies:
- SunPower’s Maxeon 2 and 3 Series solar panels – performance warranty up to 92% after 25 years
- LG’s Neon R and Neon 2 – minimum 90% and 90.8% performance warranty after 25 years
- Panasonic’s HIT N335W – performance warranty of 90.76% after 25 years
Best Solar Panels for Partially Shady Areas
If your roof only gets full sun for part of the day, you might think that solar panels won’t work for you. Happily, clever engineers have found a solution: split modules with half-cut cells.
These panels, which have a junction box in the center of the module, essentially provide two halves of a full panel that work in tandem when the sun is full but don’t rely on the other half when shadier conditions prevail.
These half-cut panels also have increased performance because the current collectors (bus bars) can be thinner (because each cell produces the same voltage, just at half the current). Thinner bus bars means less resistance and energy loss, lower temperatures (and greater efficiency) and a greater cell surface area.
Most major solar providers now offer split panels, but REC Twin Peak panels were some of the first and are still some of the best.
Best Solar Panels for Wind Prone Areas
Nobody wants to invest a cool $20k on solar panels only to have them wrenched from the roof or mangled beyond recognition in a wind-storm. So, if you live in a particularly wind-prone area and are considering a solar array, look for panels with extremely strong framing and a reputation for standing up to a good whipping wind.
Some good options include Winaico and Q.Peak DUO panels from QCELLS. The Q Peak DUO Black-G6+ is manufactured with larger cells for 6% more power and can provide up to 345 W. These panels are made in Georgia, have a 25-year warranty and a guaranteed 85% of initial performance up to 25 years. Winaico’s panels have an impressive reputation for durability and the company has led the way for years on durability and innovation to make panels more resistant to wind, hail, and other weather extremes.
Cost per Watt
If you’re staring at two solar panels that look pretty much the same, with a similar efficiency rating, warranty, and temperature coefficient, you might want to consider the cost per Watt as a tie-breaker.
Full-sized panels typically provide 275-400 Watts, and most come in at less than a dollar per Watt. For the most efficient and best performing solar panels, such as those made by SunPower and LG, using N-type monocrystalline silicon cells, the cost may be significantly higher. So, be sure to compare like for like.
Warranty and Service Record
If you choose well and are lucky, your shiny new solar panel array may be with you for the next 25 or even 30 years. The best companies around will offer a warranty that covers those panels for at least two decades and will still be around to make good on any warranty should you need to make use of it. After all, what good is a 30-year warranty from a fly-by-night company that can’t or won’t honor it.
Thankfully, several of the best solar panels around are made by companies with a good track record for longevity and service, including LG and Panasonic.
A materials or equipment warranty protects your solar panels against failure that arise as a result of environmental factors or defects. Typically, LG, Panasonic, SunPower, Q CELLS, and a handful of other companies offer a 25-year warrant on their solar panels. REC’s warranty has recently been extended to cover 20 years for some panels. Always confirm warranty conditions before buying, if this is a key concern for you.
SunPower are also a big name in solar panels, but the company is currently facing some challenges as it morphs into a new entity called Maxeon Solar. Until this spin-off company has been shown to be solvent, I’d recommend anyone buying solar panels in the next year or so to choose LG or Panasonic instead.
You may see the term ‘Tier 1’ in some sales and marketing materials. This rating was developed by Bloomberg New Energy Finance Corporation as a way to rate the financial stability of a solar panel manufacturer. Tier 1 has little, if any, bearing on the performance or quality of a solar panel, just the company that makes it. Most of the big names in solar panels are Tier 1 companies, making other considerations far more pressing. Interestingly, Panasonic slipped out of Tier 1 status in the first quarter of 2020, which may be related to the Japanese company cutting ties with Tesla (a relationship that seemed to be financially damaging to Panasonic).
If you have concerns over the status of a company from whom you’re considering buying solar panels, check out their warranty small print. Ideally, a warranty will be backed by a third-party. This means that even if the original company can’t support the coverage (if they become insolvent, say), your panels will stull be under warranty by the third-party, making this a low-risk option.
Ethical Solar Panels – Eco-Friendly, Low-Toxicity Solar Panels
Finally, there’s no getting around the fact that producing solar panels is an energy intensive business. Though claims that it takes more energy to produce and ship these panels than will ever be produced by the panels themselves seem rather spurious, solar panels have a few other environmental downsides too, mostly related to their composition.
Many panels now rely on rare earth metals such as gallium and iridium, which poses problems related to ethical mining. Some older style panels contain toxic heavy metals such as cadmium and lead, which can leach into groundwater and pose a health hazard for production workers, end users, and those disposing of panels at end of life. Speaking of which, solar panels are notoriously difficult to recycle because they contain such a complex mix of materials. In the US, dedicated solar panel recycling facilities have only just begun popping up, following the lead of European countries where there’s a directive mandating proper disposal of these products. No such directive or regulation exists federally in the US.
Taking note of all of these ethical issues, the Silicon Valley Toxics Coalition (SVTC), a US-based NGO, established the Solar Scorecard. This system ranks solar panel manufacturers based on their commitment to ethical policies and actions in the areas of:
- Extended Producer Responsibility
- Emissions Reporting
- Worker Rights, Health and Safety
- Module Toxicity and Materials
- Supply Chains
- Energy and Greenhouse Gas (GHG) Emissions
- Water
- Conflict Minerals
For 2018/19, the Solar Scorecard winner was Jinko, followed closely by Trina. The top 10 most ethical solar panel companies were (with maximum score out of 100):
- Jinko – 100
- Trina – 99
- SunPower – 94
- JA Solar – 92
- Hanwha Q CELLS – 90
- CS Wismar – 84
- LG – 84
- WINAICO – 84
- Silfab – 77
- AUO – 76
Unfortunately, despite having more ethical practices than competitors, not all of these companies offer solar panels favored by residential users. As such, our top picks for the best solar panels available in 2020 takes into account both the companies’ eco-friendliness and general ethics as well as performance, price, and availability. After all, it’s no particularly eco-friendly or ethical to choose a lesser quality product that only lasts a few years before it needs scrapping and replacing.
Without further ado, then, here are our top picks for solar panels.
Solar Patio?
Finally, if you really want to show off your eco-chops, think about installing solar panels on your driveway, patio, courtyard, or balcony. Platio, a Budapest-based company, shook up the industry in 2017 with their innovative space-saving, attractive and low maintenance Platio solar paving made from recycled plastic and glass. Easier to look after than roof mounted systems, the Platio system is a great choice for soaking up solar power during the day and then recharging your car when you get home at night.
No pricing, not for the DIY