Solar panels are a popular product nowadays, and there are many criteria to consider when deciding which panels to purchase for your solar energy system. As you explore solar panel reviews, it is important to include solar cell efficiency, solar panel ratings, durability, and manufacturer assurances in your decision. Solar Era has outlined the factors to keep in mind when you are evaluating solar panel performance and quality.
Criteria For Selecting Solar Panels
You do not need to know exactly how solar panels convert sunlight into electricity to make a solar purchasing decision. However, understanding how a solar panel will perform is key to determining how much you can save with your solar energy system.
There are several factors that influence how effective a panel is at converting sunlight into electricity. These are the 4 most important to understand:
Solar Panel Quality
The International Organization for Standardization (ISO) has created quality assurance standards for the manufacturing industry known as the ISO 9000 series. Solar panel manufacturers can be certified ISO 9000-compliant to indicate that they meet those standards. While lack of ISO certification is not necessarily an indicator of an inferior product, buying from a certified manufacturer is an indicator of quality.
Solar Panel Durability
Solar panel durability metrics measure how well panels will hold up over time in real world conditions.
1. IEC 61215
The International Electrotechnical Commission’s (IEC’s) 61215 reliability standard evaluates panels by performing stress tests simulating the decades of outdoor wear and tear that solar panels encounter during their lifetime. These tests are designed to identify potential premature failure problems with solar panels, and panels that meet the standard are more likely to survive in the field.
2. Snow & Wind Load
Snow can create a significant load of extra weight on a panel’s surface, and wind can apply strong pressures to the surface of solar panels. The higher a solar panel’s snow and wind load ratings, the better it is at tolerating these forces. Check solar panel ratings and reviews for the snow and wind load ratings, particularly if you live in parts of the country with greater seasonal variation.
Solar Panel Manufacturer Assurances
Manufacturers’ warranties are an important complement to solar panel efficiency, quality, and durability metrics, because they indicate both technical specifications and business practices. In the unlikely event that a solar panel problem occurs post-installation, a strong warranty ensures that your service and support needs will be covered.
1. 25-year Linear Power Output Warranty
The amount of electricity a solar panel can produce declines slightly every year, with the most significant decline happening in the first year. This is typically referred to as “panel degradation.” Many solar panel manufacturers provide a power production warranty guaranteeing that their panels will retain a certain percentage of their production capacity over the first 25 years, usually not less than 80%. For this metric, a higher percentage guarantee is preferable to a lower percentage.
Manufacturers also often provide a specific guarantee that output will only decline by a certain amount (generally no more than 0.7%) in a single year, known as the degradation rate. For this metric, a smaller percentage is better than a larger one.
2. Products Warranty
The products warranty guarantees against failures due to manufacturing defects, durability, and environmental issues. Most solar panel manufacturers guarantee that their panels will not fail for 10 to 12 years, and some extend their products warranty even further. Make sure you pay attention to the fine print – some products warranties will cover the shipping and labor costs associated with replacing a panel, but others may require you to pay those expenses.
The Difference Between Linear Power Output Warranty and Products Warranty
When a manufacturer says that their panels have a 25-year linear power output warranty and a 10-year products warranty, it can be difficult to understand how the two warranties work together. The linear power output warranty provides a guarantee that, while your panels are operational, they will produce a certain amount of electricity every year. The products warranty guarantees that the panels will not fail. However, the linear power output warranty only applies to operating panels. In the unlikely event that there is a manufacturing defect, it would most likely be evident before the products warranty expires – the power production takes over from there.
Solar Panel Manufacturers' Corporate Profile
While a manufacturer’s products and warranty coverage are the most direct ways to evaluate solar panel reviews, their corporate profile can also tell you a lot about their products.
For example:
Is the manufacturer focused solely on the solar industry? Where do they manufacture their panels? Do they deliver support with in-house staff or outsource to third parties? Do they maintain insurance coverage for their warranty services so that their warranties survive even if they go out of business?
Now that you know about how to evaluate solar panel efficiency and quality, get our team to make A Free Solar Consultation for your home or business.