Solar reviews

First Solar panels review 2024: Big in America

A company from the list of the world’s 10 largest manufacturers, First Solar makes thin-film panels for solar farms. Are they right for you? Today, we’ll weigh the pros and cons of First Solar panels to help you decide. Get ready – here comes our First Solar panel review.

First Solar story: America’s largest PV company

Founded in 1999
Headquartered in Tempe, Arizona
Top 10 largest solar manufacturers
3 manufacturing facilities in India, Malaysia, and Vietnam
3 manufacturing facilities in Ohio
Commercial- and utility-scale solar projects

Founded in 1999, First Solar is headquartered in Tempe, Arizona. They’re renowned for their advanced solar panels designed and developed entirely in the US.

First Solar stands out as the sole US company among the world’s 10 largest solar manufacturers. The company manufactures solar panels in India, Malaysia, and Vietnam, with a projected global capacity exceeding 20GW. They also have three manufacturing facilities in Ohio, aiming for a 10GW annual domestic capacity by 2025.

Commercial and utility-scale PV projects are the main focus of First Solar. Aside from manufacturing PV modules for them, First Solar offers finance, construction, maintenance of solar projects and end-of-life panel recycling.

The company is famous for using thin-film instead of more common monocrystalline solar panels. The word ‘thin-film’ might make you think of flexible solar panels, but First Solar panels are in fact rigid. Let’s take a closer look at them.

First Solar uses CadTel solar panel technology

Instead of silicon, First Solar uses a thin layer of cadmium telluride – CdTe – a semiconductor material with an exceptional ability to absorb sunlight. It works the same way as the silicon layer – when light particles strike the CdTe layer, they knock electrons loose, creating an electric current.

What makes a real difference is the amount of energy required to excite electrons. Compared to silicon, Cadmium telluride absorbs a wider spectrum of sunlight, including shorter wavelengths that silicon panels struggle to capture. This translates to some additional noteworthy characteristics:

✓ Improved temperature coefficient: CadTel panels perform exceptionally well in hot and humid climates, unlike silicon panels that experience efficiency drops under such conditions.

✓ Exceptional shade tolerance: Partial shade, a common concern for silicon solar panels, has a lesser impact on CadTel’s power output. This makes CadTel a more versatile option, suitable for rooftops with chimneys, vents, or occasional shade from trees.

✓ Excellent low-light performance: Compared to traditional silicon panels, CadTel exhibits better low-light performance. This means that even on cloudy days or during morning and evening hours when sunlight is less intense, CadTel panels can still generate a significant amount of electricity.

✓ Industry’s smallest environmental footprint: The manufacturing process for CadTel has a significantly lower carbon footprint and water usage compared to traditional silicon panels. Additionally, these panels are highly recyclable, with over 90% of their materials recoverable.

One potential concern surrounding CadTel is the presence of cadmium, a toxic heavy metal. Leading CadTel manufacturers like First Solar prioritize responsible sourcing and implement rigorous safety measures throughout production and recycling. This ensures minimal environmental impact and promotes a sustainable life cycle for the technology.

What CadTel panels still lack is efficiency. So far it lags at the level of already outdated polycrystalline panels at 17–19%. First Solar’s research and product development teams project that CadTel thin-film efficiency will hit 25% by 2025 and 28% by 2030.

First Solar panels: A promising option

17.5% – 20%


First Solar panels come in different wattages, ranging from 430 to 550 watts per panel. Efficiency-wise, First Solar panels fall between 17.5% and 20%. While not the highest compared to silicon solar panels reaching 23% and beyond, these values are pretty good for thin-film solar panels.

10 – 12 years

product warranty

The company offers a comprehensive warranty on their panels for both product and performance. A 10-to-12-year product warranty protects your investment from defects in materials or manufacturing. A 25-to-30-year performance warranty guarantees 90% of the rated power output and even above during this timeframe. Again, not the highest on the solar market, but one of the best in the thin-film segment.

First Solar panels prices are lower than average — especially for a company with American manufacturing, and especially for a company that deals with thin-film panels. Competitive pricing is the main reason First Solar is doing so well on the market of commercial-scale solar. 

First Solar panels: Pros

Let’s review the strengths and weaknesses of First Solar panels. Here’s what we do like about them:

✓ American-made: As the only US-headquartered company among the top 10 solar module manufacturers globally, First Solar supports American jobs and manufacturing.

✓ Durability: First Solar panels can withstand harsh weather conditions, including extreme temperatures, hail, and even sand abrasion, making them ideal for diverse environments.

✓ Low-light performance: Strong performance in low-light conditions translates to efficient energy production even on cloudy days or during mornings and evenings when sunlight is less intense.

✓ Temperature coefficient: With a lower temperature coefficient, First Solar panels experience minimal efficiency loss on hot days, maximizing energy production in warmer climates.

✓ Responsible manufacturing: First Solar prioritizes responsible production practices and emphasizes sustainability throughout their manufacturing process. For environmentally conscious consumers, this can be a significant advantage.

First Solar panels: Cons

Sounds tempting, but… not perfect. Here’s what we don’t like about the panels:

✗ Low efficiency: First Solar offers good efficiency ratings for thin-film solar panels. Still they’re not as high as those of silicon panels reaching 23% and above, which may be a drawback for those looking to get the most out of the available space.

✗ Weak product warranty: A 10-12 year product warranty is good among thin-film panels. The manufacturers of top-of-the-line silicon modules offer warranties of up to 25 and even 30 years though.

✗ Commercial/industrial focus: First Solar panels are designed for large-scale projects. Finding First Solar panels for sale on the retail market can be hard. There is little reason for homeowners to install First Solar panels and they might be better off with other brands.  

First Solar panels overview: For all sorts of projects

Time to move from specs to actual panels. Let’s take a glance at what First Solar is offering to the market:

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First Solar Series 6 – The basics

A cost-effective option, the Series 6 panel delivers a wattage range of 430–460 watts with a 17.4%–18.6% efficiency rating. The panel boasts a 12-year product and a 30-year performance warranty guaranteeing about 90% of initial output. While not the most powerful panel in the lineup, it offers a balance between affordability and performance, making it suitable for budget-conscious buyers.

First Solar Series 6 Plus – Advanced option

Series 6 Plus offers a bit higher performance to the Series 6 with a wattage range of 455–480 watts and a better 18.1%–19% efficiency. With a strong 30-year performance warranty guaranteeing about 90% of initial power, this panel is a well-rounded option for residential and commercial applications.

First Solar Series 6 Plus Bifacial – Double glass

Series 6 Plus Bifacial boasts a high-power range of 455 to 480 watts, efficiently converting sunlight into electricity at a rate of 18.1% to 19%. Compared to the previous model, this panel boasts a bifacial design, capturing sunlight hitting both the front and back, generating an additional 15% power gain. To top it off, the panel comes with a 30-year performance warranty, guaranteeing at least 90% of its initial power output for three decades. This translates to a reliable and long-lasting clean energy solution your business can depend on.

A1 SolarStore recommends First Solar Series 7

First Solar Series 7 panel boasts an impressive leap in power output, generating between 525 and 550 watts per panel. This significant increase in wattage is accompanied by an equally impressive efficiency rating of 18.8% to 19.7%. First Solar backs the panel with a 12-year product and a 30-year performance warranty, guaranteeing about 90% of the rated power output after three decades. A powerful option for ambitious projects.

A1 SolarStore verdict: For grand projects only

In closing the First Solar panel review, let’s list some key facts about the brand and its products:

  • Founded in 2022, First Solar is the only US company among the world’s top 10 solar manufacturers.

  • Headquartered in Arizona, the company has three manufacturing facilities in Ohio and three more in India, Malaysia, and Vietnam.

  • First Solar projects global capacity exceeding 20GW by 2025.

  • The company focuses on commercial and utility-scale projects.

  • They’re renowned for their advanced CadTel thin-film solar panels – a technology designed and developed entirely in the US.

  • First Solar panel’s power output ranges from 430W to 550W, while their efficiency floats from 17.4% to 19.7%.

  • First Solar panels are backed up with a 10-12-year product and a 25-30-year performance warranty.

First Solar panels demonstrate a wealth of advantages: they work perfectly well in low light, don’t fear shadows, are damage-resistant, recyclable and sustainable. What these panels lack is efficiency. While this may not be so critical in large-scale solar projects, which the company primarily focuses on, but for small home installations, every inch counts. So if you’re looking for a home solution, this may not be your brand. With that, we end our First Solar panels review. Subscribe to our newsletter at the bottom of the page to get fresh brand reviews and learn about the latest arrivals!

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Years of experience in translation and a love of nature help Julia find the right words to encourage going solar. She joined the team in 2023 and is happy to make her contribution to a greener future.

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