SunPower, LG or Panasonic, who is the best of the best in 2018?

As the solar industry has expanded so has the number of available brands of panels. Brands such as SunPower, LG or Panasonic have dominated a large sector of the market for a long time. However every panel is different in more ways than meets the eye, it can be quite difficult as a homeowner to make the right decision.

There are three main criteria to judging a solar panel brand:

  • Warranty
  • Efficiency
  • Performance

Solar panels have two types of warranty, a product warranty and a power output warranty. The product warranty covers the product if it fails as a result of a manufacturing floor or poor quality components. The power output warranty is a guarantee that the panel will produce a certain percentage of its rated power after a certain number of years. SunPower, LG and Panasonic all have a product warranty of 25 years, 15 years longer than the industry standard of 10 years.

Power output warranty of LG, SunPower and Panasonic:
BrandOutput year 1Annual Degradation rateOutput year 5Output year 10Output year 25
SunPower 95% 0.4% year 5 onward 95% 93.12% 87%
LG 98% 0.4% 96.06% 94.15% 88.4%
Panasonic 97% 0.26% 95.75% 94.51% 90.76%

Why is panel efficiency important?

The efficiency of a solar panel is the percentage of light that hits the panel and is converted into energy. A solar panel with a higher efficiency will require less space to reach a desired output.

Average efficiency of LG, SunPower and Panasonic panels:
BrandHighest efficiency (available)
SunPower 22.8%
LG 21.1%
Panasonic 19.7%

The industry standard for solar panel efficiency is about 17%, a key reason for SunPower, LG and Panasonic dominating a large share of the solar market is because they have the best solar cell technologies.

How well do LG, Panasonic and SunPower panels perform in the heat?

Like most electronics solar panels produce less energy the warmer they become. A great way to rate a solar panel is to look at its temperature coefficient. A temperature coefficient is the percentage decrease in power output for every degree celsius the panel reaches beyond 25°C/77°F. The temperature coefficient is a great indicator as to which panels will hold up best in real world conditions.

Temperature coefficient of SunPower, LG and Panasonic panels:
BrandTemp. Coefficient
SunPower -0.29%/°C
LG -0.30%/°C
Panasonic -0.258%/°C

For example SunPower claim their panels power output will decrease 0.29% for every degree celsius over 25°C/77°F.

How much do solar panels cost?

The cost of installing solar panels in 2018 will vary depending on the installation company, equipment and associated permitting costs.

Consumers on our site have told us that they’ve paid about $3.80 per watt for a fully installed SunPower system with a decent brand inverter. Consumers that installed LG or Panasonic panels paid $3.40 per watt on average.

Which premium solar panel is best overall?

There is no perfect panel for everybody, each brand offers a slightly different warranty, efficiency and temperature coefficient. There are no bad choices out of SunPower, LG or Panasonic. If roof space is tight and money isn’t an issue perhaps opting for the slightly higher efficiency SunPower X-series model is best, however, if you’re looking not to spend so much or have a larger roof, a Panasonic or LG model may be a better choice.

What incentives are available for installing solar panels for home?

Your local solar incentives will vary based on location but luckily all Americans can claim 30% of their system cost as a deduction to their federal taxes under the federal solar tax credit. For a free estimate of how much solar will cost you with local incentives included enter your zip code below.

How much does a SunPower, LG or Panasonic solar panel system cost?

See local incentives available for installing solar panels on your home

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