Tesla solar panels: What you need to know

In 2016, Tesla entered the solar industry when the Elon Musk-led company acquired SolarCity and began offering home battery storage and solar installations. Making the jump from an electric vehicle (EV) manufacturer to a broad clean energy solutions provider, Tesla continues helping homeowners achieve energy independence. In addition to its popular Solar Roof, which replaces traditional roofing materials with small photovoltaic solar shingles, Tesla also offers traditional solar panels.

When evaluating solar panel options, it's essential to compare what's available to be confident in your solar investment. Let's look at Tesla's solar panel technology and how it compares to other leading solar panel brands available today.

After Tesla acquired SolarCity in 2016, they manufactured panels with solar cells from Panasonic, producing them in their Gigafactory in Buffalo, NY. The partnership ended in 2020, though the two companies still collaborate on battery technology for Tesla's vehicles and Powerwall home batteries. Tesla then began sourcing solar panels for its installations from multiple solar providers, including Q CELLS. Currently, Tesla offers two lines of solar panels: the S-series and the H-series.

S Series

Tesla's S series panels come in three different output ratings: 420 Watts (W), 425 W, and 430 W. The maximum efficiency of this panel series is 19.8%, but it varies based on output. The panels are available in a black finish without visible grid lines and also include Tesla's low-profile installation technology. This technology stemmed from their 2016 acquisition of SolarCity, which had previously acquired Zep Solar in 2013, a company that manufactured low-profile solar panel mounts. 

The system also includes "skirts" that create a beveled edge wrapping around the solar panel installation, making the system appear more integrated into the roof. While neither the skirt nor the low-profile mounting panels are Tesla-exclusive innovations, they help Tesla maintain its sleek branding across its renewable energy products.

H Series

Tesla's H series panels also come in three different output ratings: 395 W, 400 W, and 405 W. This series is more efficient than its counterpart, with a maximum efficiency of 20.6%. The H series has the same black finish and uses the same mounting technology and skirt system as Tesla's S series.

It's also important to note that Tesla panels are only available through Tesla, and Tesla solar systems are only available in four sizes: 

• Small, 4.8 kW, 12 panels

• Medium, 9.6 kW, 24 panels

• Large, 14.4 kW, 36 panels

• Extra-large, 19.2 kW, 48 panels

We'll dive into the efficiency ratings, performance, and warranties of Tesla solar panels below.

There are four key metrics that you should review as you evaluate solar panel quality and determine the best solar panels for you: efficiency, performance, warranty, and price. We'll explain what each of these means and why they're important – and show how Tesla solar panels stack up against each other and other leading brands in the solar industry.

Efficiency

"Solar panel efficiency" or "conversion efficiency" refers to how well a solar panel captures sunlight and converts it into usable photovoltaic electricity. In the same conditions, a high-efficiency solar panel will produce more electricity than a lower-efficiency panel of the same size. If you're choosing between panels, models with higher efficiency ratings are generally preferable.

The efficiency of your Tesla solar panels will vary depending on the specific model you choose for your system. Tesla panel efficiency ranges from 19.3% to 20.6%. SunPower claims the top spot on the Marketplace regarding panel efficiency, with its M Series 440W panels boasting the highest efficiency rating of any home solar panel on our Marketplace at 22.8%. Tesla's panels are middle of the pack in terms of efficiency range but still have adequate efficiency for panels being offered today.

Tesla panel series efficiency

Performance (temperature coefficient)

Temperature coefficient indicates how well your solar panels perform in less-than-ideal conditions. Solar panels, like other electronic equipment, perform better when kept cool (ideally around 25°C/77°F). The temperature coefficient tells you how much your panel's performance will change during hot, sunny summer days.

For every degree above 25°C (77°F), your solar panel's electricity production will decrease by its temperature coefficient. The temperature coefficient of Tesla's H series is -0.34%/°C, while the temperature coefficient of the S series is -0.331%/°C. This means that if your panel's temperature increases by one degree from 25°C (77°F), its electricity production will decrease by 0.34% for the H series and 0.331% for the S series; if its temperature rises to 35°C (95°F), electricity production will reduce by 3.4% for the H series and 3.31% for the S series. 

Your solar panels will likely see more than a few hot and sunny days each year, so ideally, they will have the lowest temperature coefficient possible. For comparison, the most popular brand of solar panels on EnergySage, Q CELLS, offers panels with a temperature coefficient of -0.34%/°C, while Panasonic panels all have a temperature coefficient of -0.26%/°C.

Tesla panel series temperature coefficient

Warranties

Whether you're buying a TV, a car, or solar panels, the brand should stand behind its product with a strong warranty. A solar panel's materials warranty (sometimes referred to as the product or equipment warranty) is a guarantee from the company that they will replace your panel if it fails due to manufacturing defects or environmental issues.

Tesla offers a 25-year warranty, guaranteeing that their panels will still produce at least 85% of their original output by the end of the warranty term for the S series and 86% for the H series.

As with most warranties, Tesla's warranty covers the degradation of the panel quality but not any corrosion from elements like salt water. You can see the degradation warranty coverage of all of Tesla's panels in the table below.

Tesla panel power output warranty

For many homeowners, the final decision around the solar equipment they choose rests on cost. The total price for a solar energy system with Tesla panels will vary depending on the other equipment (such as inverters and mounts) used in the installation and the characteristics of your roof. Tesla produces its own inverter and racking systems, which factor into your total cost estimate in your quote, along with installation costs.

Based on data from the EnergySage Marketplace, we know that Tesla systems are typically priced between $3.03 and $3.35 per watt. Since Tesla systems are offered in pre-set sizes, we've estimated cost ranges for all four system sizes below.

Tesla system cost ranges

Notably, most homeowners pay much less than the total gross cost. Tesla offers a price match guarantee if you provide a cheaper quote from another solar company for the same system size within 14 days of receiving your Tesla quote. There are also plenty of federal and state solar incentives and rebates to help reduce upfront costs, including the 30% federal Investment Tax Credit (ITC) for solar. However, with Tesla's solar rental program, Tesla owns your solar energy system and claims these benefits. This is also the case when leasing solar panels; the third-party company claims the ITC benefits. If you finance your Tesla solar panels with a loan, be sure to ask if you receive any federal and state incentives or if you're expected to pay those back to cover the cost of the loan. 

As with any product that is such a significant investment, Tesla panels have advantages and disadvantages to consider. Whether your primary motivation for switching to solar is sustainability or lowering your electric bills, it's important to weigh your options.

Pros of Tesla solar panels

• Integration with other Tesla energy products: A Tesla solar panel system is installed entirely by Tesla, from the Tesla solar inverters to the Tesla solar battery (if you choose to have battery storage). You can easily integrate it with a Tesla Wall Connector EV charger if you have a Tesla EV, and you can easily monitor your energy consumption with the Tesla app.

• Cost: Tesla panels are affordable compared to other panels on the market, and with their price match guarantee, you'll get a good deal on them if you are set on going solar with Tesla.

Cons of Tesla solar panels

• Unpredictability: The Tesla solar installation process is not as easy as with many other solar companies. As with many of Tesla's products, you'll likely be put on a waitlist before moving forward with the solar installation process. We've also heard a lot of complaints about customer service.

• Efficiency: Tesla panels are not a standout in the market regarding efficiency, so if that is your main concern, you should consider exploring other options.

• Set sizing: As outlined above, Tesla systems are only available in four pre-set sizes. The size you install will depend on the size of your existing roof. It also may not meet all your electricity needs, leaving you to fill in the gaps on your utility bill.

There are pros and cons to buying, renting, and leasing models for going solar; the option that makes the most sense for you depends on several key criteria.

1. Buying upfront: This option makes the most sense if you have the money to pay for your solar panels upfront and anticipate being in your home long enough for the system to pay for itself. In this case, you eliminate your monthly electric bills for two or three decades in the future, and studies show that solar increases your home property value by 3-4%.

2. Buying with a loan: Financing a solar purchase with a loan does not have an upfront cost, but it still offers the benefits of owning your solar panels outright, such as increasing your home's value. 

3. Renting: While no longer available, with Tesla's solar renting program, you could install solar panels on your home with basically no risk, securing fixed monthly payments for solar that were likely lower than your electric rate and allowing you to effectively trial powering your home with solar. If you didn't like it or planned to move, Tesla would remove the installation.

4. Leasing: This option makes the most sense if you want to power your home with solar but don't want to pay upfront for the installation and don't care as much about the increased home value associated with owning solar panels. 

If you're a diehard Tesla fan willing to wait out possible production delays, it may be worth looking into Tesla solar panels–but you should always compare multiple offers from different solar installers before making a final decision. Use the EnergySage Marketplace to receive multiple quotes from vetted installers near you. If you're interested in specific equipment (Tesla or otherwise), make a note in your profile when registering.