Once you’ve made the decision to invest in solar energy, you’ll have a few more decisions to make regarding product selection and installation. The selection of solar panels is always a balance between cost and quality. Different manufacturers produce low-end, mid-range, and high-end panels, and generally speaking, the larger the upfront investment is, the greater the savings you can expect over time. Since efficiency and durability are crucial, it’s recommended that you choose the highest quality solar panels that your budget will allow.
Checking the Nameplate Rating
The nameplate rating is one of several factors you should consider when selecting the best solar panels for your home or commercial building. This rating indicates how much power the panel will produce. Most solar panels have a nameplate rating between 200 and 350 watts. The higher the number is, the more power the panel is capable of producing. The nameplate rating is determined under industry-standard test conditions, and it’s important to note that these are ideal conditions in terms of sun exposure, cloud cover, and atmospheric conditions. In other words, you can’t expect a solar panel to produce its maximum wattage all the time. However, the nameplate rating is still a useful feature to consider when you’re shopping around for solar panels.
Analyzing the Efficiency Rating
If you’re interested in purchasing the best solar panels available, you’ll want to take a close look at the efficiency rating. The efficiency rating measures the number of kilowatt-hours (kWh) produced per watt on the nameplate rating. Solar panels are based on a photovoltaic system. The higher the efficiency rating is, the better the panel is at converting sunlight into electricity. The average efficiency rating throughout the industry is 16% to 18%. This may sound low, but bear in mind that when solar energy was in its infancy, an efficiency rating of 10% was considered impressive.
Today, an excellent efficiency rating is 20% to 22%. While it’s possible for manufacturers to produce more efficient panels, they generally don’t because the technology isn’t scalable. In other words, it would cost more to purchase a panel with a very high efficiency rating than the additional savings you would get from it.
Taking a Look at the Temperature Coefficient
As important as the nameplate and efficiency ratings are, they aren’t the only numbers you should consider when shopping around for solar panels. The temperature coefficient is also important, particularly in the very hot climate of Arizona. Although it may seem counterintuitive, solar panels actually perform less well during times of extreme heat. This means that homeowners in the Tucson area need to consider the performance of the panel at high temperatures. When manufacturers test their solar panels, they do so under industry-standard test conditions, which include testing at 77 degrees Fahrenheit. For every degree above this temperature, a panel can lose a percentage of efficiency.
As an example, let’s say a solar panel has a temperature coefficient of -0.258%. This means that the efficiency decreases by 0.258% for every degree the temperature rises above 77 degrees Fahrenheit. For every degree the temperature falls below 77 degrees Fahrenheit, the efficiency increases by 0.258%. For homeowners in Arizona, a small temperature coefficient is ideal. Solar panel contractors can also take measures to mitigate the effects of the heat when they install the panels. For example, they can elevate the panels slightly above the roof to allow for air circulation.
Evaluating the Manufacturer’s Warranty
Although solar energy will give you significant savings on a long-term basis, it does require an upfront investment. You can protect your investment by choosing solar panels from a manufacturer that offers a solid warranty. Solar panels are generally protected by two types of warranties: performance and equipment. The performance guarantee reassures consumers that the solar panel will continue to perform at a minimum electricity production threshold for a set period of time. It’s typical of a performance warranty to promise 90% production at 10 years and 80% production at 25 years. This is because, like many other products, the performance of solar panels can degrade over time.
The equipment warranty is also sometimes called the product or materials warranty. It covers the actual panels, rather than their performance. An ideal equipment warranty will protect purchasers from panel damage due to environmental issues, premature wear and tear, and manufacturing defects. Manufacturers typically offer a 10- to 12-year equipment warranty.
At Custom Solar and Leisure, you can find the expert guidance you need to choose the best solar panels for your building. Our solar power company has been serving the greater Tucson area for over a decade, and we’ve been ranked in Solar Power World’s top list of contractors for three years running. Our solar experts will be happy to answer all of your questions about panel selection, installation, and usage. Call us today at (520) 314-3768