LONGi Solar
LONGi Solar is a global provider of solar panels. With costs that fall below the industry average and panel efficiency high enough for the average consumer, LONGi solar panels are worth the investment.
Our rating: 3.6
Best for: Affordability
Average cost: $2.40 to $2.67 per watt
LONGi Solar at a glance
Known as one of the largest suppliers of monocrystalline products globally, LONGi is well-regarded for its commercial and residential solar panel installations.
Fast facts
- LONGi Green Energy Technology Co., Ltd. (LONGi) was founded in 2000 with the aim of becoming the most valuable solar technology company globally.
- The company ranks No. 168 in the Fortune China 500.
- LONGi has maintained AAA ratings for its Module Bankability for seven consecutive assessments, according to PV Tech.
- LONGi has been recognized as a 100% “Bankable” Solar Module Brand three consecutive times by Bloomberg New Energy Finance.
What we like
Our research shows that LONGi Solar has the most global solar panel installation coverage, completing work in 150 countries on six continents. It is committed to sustainability through comprehensive recycling and reuses more than 90% of its module products. Also, the company has ambitious energy-saving targets, aiming for 10% to 15% reductions in electricity unit consumption by 2025.
A Tier 1 solar panel brand, LONGi Solar integrates state-of-the-art features like PERC (passivated emitter and rear contact) technology, which enhances solar panel efficiency by reducing energy loss and maximizing electricity generation from the sun’s rays. All its panels are half-cut cell modules, increasing their efficiency.
What we don’t like
While LONGi’s solar panels meet the needs of the average homeowner, it has a limited selection of residential solar panels. Despite a standard 25-year performance warranty, some of LONGi’s products only have a 12-year product and workmanship warranty, which is shorter than what the best solar panel companies typically provide (comprehensive 25-year warranties).
LONGi Solar pros and cons
LONGi Solar panels may not boast the highest efficiency ratings on the market, but 21.3% is plenty for the average homeowner, especially for a cost below the industry average.
However, homeowners in states that get particularly hot weather should look for another provider, as some LONGi modules have a higher temperature coefficient than we see in competitors — this means they won’t perform as well in hot climates.
Pros
- Durability and reliability
- Tier 1 panel brand
- Extended power warranties (25 or 30 years)
Cons
- 12-year product warranty
- Limited selection of solar panels
- High temperature coefficient in some modules
How much does LONGi Solar cost?
The cost of LONGi Solar panels can vary. Installation difficulty and shipping expenses are two things that can change, making it challenging to pinpoint costs.
LONGi solar panels cost an average of $2.40 to $2.67 per watt, as of 2023. This price is cheaper than the industry average of $2.82 per watt, making LONGi panels a cost-effective option.
Given the average prices, here is what you can expect to pay for a 7 kW LONGi solar array:
- Cost before federal solar tax credit: Approximately $16,800 to $18,690
- Cost after federal solar tax credit: Around $11,760 to $13,083
Our review of LONGi solar panels finds that the brand is a practical and economical choice for those interested in solar energy, offering competitive prices and high efficiency ratings.
Additional factors impacting installation cost
Other factors that affect the installation cost of a LONGi Solar array include:
- Size of the solar system
- Installation complexity
- Location and regional incentives
- Additional components required (inverters, mounting hardware, etc.)
LONGi Solar products and services
LONGi Solar primarily focuses on residential and commercial solar panel manufacturing and servicing. While LONGi Solar has a global presence with innovative technologies like Smart Soldering technology, having a product warranty that is shorter than those of some competitors is cause for concern.
LONGi Solar partners with other companies to offer solar batteries, inverters and microinverters, but it doesn’t make these products for residential use.
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Offered?
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|---|---|
| Solar panels | ✔ |
| Solar shingles | X |
| Microinverter | X |
| String inverter | X |
| Solar battery | X |
| Product warranty | 12 - 25 years |
| Performance warranty | 25 - 30 years |
| Workmanship warranty | 12 - 25 years |
| Solar battery warranty | N/A |
| Micro inverter warranty | N/A |
What types of solar panels does LONGi Solar have?
LONGi sells four primary solar panel models: Hi-MO 9, Hi-MO 7, Hi-MO X6, Hi-MO 5 and Hi-MO 5m. The Hi-MO 5m Series is the company’s residential line. Bifacial solar panels are mostly used in commercial settings.
The most efficient solar panels typically have an efficiency above 22%, but 19% is just fine for residential use. LONGi’s solar panels fall at the higher end of that range. They may not be the most efficient solar panel available, but will perform well for residential use.
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Power output
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| Hi-MO 5m LR5-54HPH | 405 - 425 W |
| Hi-MO 5m LR5-72HPH | 525 - 565 W |
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Efficiency
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|---|---|
| Hi-MO 5m LR5-54HPH | 20.7% - 21.8% |
| Hi-MO 5m LR5-72HPH | 21.1% - 21.9% |
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Temperature coefficient
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| Hi-MO 5m LR5-54HPH | -0.34%/°C |
| Hi-MO 5m LR5-72HPH | -0.34%/°C |
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Annual degradation rate
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|---|---|
| Hi-MO 5m LR5-54HPH | 0.55% |
| Hi-MO 5m LR5-72HPH | 0.55% |
LONGi Solar panel performance
LONGi Solar uses Gallium-doped silicon, which improves panel stability and reduces light-induced degradation (LID) — or how solar panel efficiency decreases after sunlight exposure. So, LONGi’s solar panels suffer less damage and last longer.
Most panels use Boron-doped P-type silicon wafers, and these degrade faster, with 83% power retention after 25 years. LONGi’s solar panels lose only about 2% of their initial power rating in the first year and under 0.55% per year after that. Their solar panels keep about 85% of their original power over a 30-year period. This is consistent with other solar panel brands.
LONGi Solar also has a unique soldering technology using triangular-shaped micro busbars with flat ends. The metal strips are tiny and help gather electrical currents. This reduces gaps between solar cells, which means less wear and tear (by about 0.3%).
LONGi product warranties
LONGi Solar’s warranty terms, while offering a 12-year product warranty, are shorter than those of other competitors in the industry. Panasonic Solar and REC Solar typically provide more extensive product warranties, lasting up to 25 years.
LONGi Solar has a much longer power warranty, extending for 25 or 30 years, depending on the solar panel model. The extended power warranty ensures that the panels maintain a guaranteed level of power output over the designated period, aligning with industry standards and offering long-term performance assurance to customers.
How does LONGi compare with competitors?
LONGi Solar has innovative panel types, including p-type TOPCON, n-type TOPCON, n-type HJT and p-type HJT.
JinkoSolar’s panels are highly efficient, making them ideal for smaller roof spaces or regions with limited sunlight exposure compared to many other brands. Similarly, REC Solar scores well in our methodology for installation in harsh environments.
Homeowners seeking American-made products should look at Mission Solar, while LONGi is the overall best brand for the global solar market. Canadian Solar’s panels are the go-to for high-power output.
Depending on individual needs, consumers may prioritize factors like panel type, efficiency or eco-friendly manufacturing. For more, check out our picks for the seven best solar panels money can buy, and explore our full comparison of each competitor below.
LONGi vs. competitors
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Our score (out of 5 stars)
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| LONGi Solar | 3.6 |
| Panasonic Solar | 5.0 |
| Mission Solar | 4.5 |
| Jinko Solar | 4.2 |
| Canadian Solar | 3.8 |
| ZNShine Solar | 3.7 |
| REC Solar | 3.6 |
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Annual degradation rate
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| LONGi Solar | 0.40% - 0.55% |
| Panasonic Solar | 0.25% - 0.5% |
| Mission Solar | 0.40% - 0.58% |
| Jinko Solar | 0.40% - 0.60% |
| Canadian Solar | 0.35% - 0.55% |
| ZNShine Solar | 0.40% - 0.55% |
| REC Solar | 0.25% |
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Panel types offered
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| LONGi Solar | p-type TOPCON, n-type TOPCON, n-type HJT, p-type HJT |
| Panasonic Solar | Monocrystalline, HJT, PERC, IBC, p-type, n-type |
| Mission Solar | Monocrystalline, PERC |
| Jinko Solar | Monocrystalline, PERC, n-type |
| Canadian Solar | Monocrystalline, HJT, PERC, n-type, Bifacial |
| ZNShine Solar | Monocrystalline, polycrystalline |
| REC Solar | Monocrystalline, HJT, n-type, Bifacial |
Methodology
To determine the best solar panels, the CNN Underscored editorial team analyzed 170 panels based on wattage, efficiency, price range, durability and warranty, considering 14 features across 30 data points from 133 primary sources.
Our methodology assigns weights to each category: solar panel output (25%), price range (20%), efficiency range (20%), durability and adaptability (20%), and warranty (12%). We also incorporate editorial judgment (3%) for appearance, sustainability and integration with other components.
Readers can trust our expert advice for its comprehensive evaluation and impartial rating system, ensuring informed decisions based on crucial criteria and percentages.