Technological advances have transformed the solar energy industry in recent years. Solar panels are significantly more efficient, producing more power in the same amount of space. Meanwhile, prices continue to fall, reducing the cost of solar electricity.
But with the introduction of new technologies comes uncertainty. Which solar panels are the most reliable and durable? What technology creates the least amount of pollution in the manufacturing process? Let’s explore some of these critical issues in the pursuit of the best solar panels on the market.
Solar Panel Considerations
Solar panels have become significantly more efficient in recent years. And the more efficient a solar panel is, the more energy can be generated in a given space. Space becomes more critical when there are constraints due to the size or your roof or property. Unfortunately, more efficient panels typically cost more. If space isn’t an issue, efficiency becomes less crucial. For installations limited by space, panel efficiency is an important consideration. It is also important to consider the long-term efficiency of solar modules.
Long-Term Power Generation
Like most other things, solar panels degrade over time. They become less efficient in turning sunlight into electricity. This is important because solar panels can last 30 years and you want your solar system to be churning out a lot of energy a couple of decades from now, even if someone else owns the home.
Solar panel manufacturers offer a power production guarantee to ensure a certain level of output over a given time. Many solar panel manufacturers provide a guarantee of 90 percent production for 10 years and 80 percent for 25 years.
Some manufacturers differentiate themselves by offering stronger warranties. SunPower, for example, leads the industry by offering a 92 percent performance guarantee for 25 years. The higher the value of the 25-year production warranty, the more power the panels will generate 25 years down the road.
Product warranties cover defects and failures. Solar panel warranties vary a lot by the manufacturer. SunPower, LG, and Solaria all offer a 25-year warranty, whereas Trina offers just a 10-year warranty. The longer the warranty, the lower the investment risk. In many cases, a more extended product warranty means higher solar panel prices.
The Silicon Valley Toxics Coalition (SVTC) is dedicated to a safe and sustainable solar photovoltaic (PV) industry. They produce a solar scorecard that rates manufacturers on extended producer responsibility, supply chain, workers rights, emissions reporting, module toxicity, greenhouse gas emissions, conflict minerals, and water use. The companies with the highest ratings are the most sustainable.
Solar Panel Module Testing
Look for DNV GL test results. The company tests solar panels for reliability and durability for common degradation mechanisms. Solar panel performance has a huge impact on the solar electricity of an array over time. Such testing helps ensure high-quality panels, reducing financial risk.
DMV GL produces a list of top-performing PV panels that lead in product reliability.
Most solar panels are manufactured in Asia, Europe, or North America. Modules that are made in the United States tend to be more expensive. But some solar shoppers want to support domestic manufacturing. Many companies produce panels in two or three countries. For example, SunPower products are made in the United States, the Philippines, and Mexico. Keep in mind that the manufacturing location and the company’s headquarters are not necessarily the same. Also, the manufacturing location isn’t necessarily an indication of quality. Panels that are manufactured closer to the installation site might have lower emissions related to transportation of the product.
Top Solar Panels Comparison Chart
We compared the efficiency, warranty, environmental performance, and more of the following solar panel models in the comparison chart below.
- SunPower X22
- Trina Solar TSM
- Hanwha Q CELLS Q.Peak Duo
- REC Solar N-Peak
- LG Electronics NeON R
- Solaria PowerXT
- Adani Solar ASP-7-AAA
A Dynamic Industry
At times, supply delays and surpluses have plagued the solar industry. For example, China slashed solar subsidies for domestic solar installations in May 2018. This move created a lag in demand, causing a surplus of solar panels and falling prices across the industry. Thankfully, this surplus supply has helped offset the impact of the U.S. solar tariff that was recently enacted.
Because solar panel technology is advancing, the market is very dynamic. New products are frequently being released as others become obsolete. The most efficient solar panels on the market today will probably not seem so efficient in a decade as the technology matures. Companies that are relatively unknown could capture a larger share of the market.