A solar project is completed in the United States every 2.5 minutes, according to GTM Research. In the past five years alone, large builders like Lennar, KB Home, and Meritage have added solar panels as a standard feature on many of their residential developments.
In addition, builders and architects can sell solar-equipped homes at premium prices, providing higher profit margins in hypercompetitive markets. Typically, homes with solar panels sell 20% faster, with a 17% higher price, according to a nationwide study by Sandia National Laboratories, a finding confirmed by a separate study by Berkeley Lab.
As more homeowners and developers install solar, the quality of the solar installation’s panels will be key to ensuring new home warranties and homeowner satisfaction over the expected 25-year life of the solar system. The following five questions provide builders a framework within which to pick the highest-quality solar panels for their projects.
1) What makes a
panel high quality?
While solar panels often look remarkably similar to the casual observer, significant differences exist that can affect panels’ performance over their more than 25-year life cycle in outdoor environments. It’s also challenging to understand the performance or quality of solar panels purely by looking at them, in the same way it would be difficult to gauge the performance or reliability of semiconductors (similar both in materials and manufacturing processes to solar panels) visually.
Solar products that perform well and are durable depend on component design, effective materials and component selection, proper supply chain management, measurable quality manufacturing processes and facilities (think Toyota Production System or Six Sigma) and stable, secure companies backing products with effective long-term product and performance warranties.
Do your due diligence into the panels the
installer recommends. Look for companies that provide information on:
● consistent quality of key input components and materials (silicon/wafers/cells) by a fully automated process;
● manufacturing best practices ensuring consistent quality within volume production batches;
● product design appropriate to maximize energy harvest; and
● low warranty-claims rates. A claims rate of 100 parts per million (ppm.) is a benchmark of leading manufacturers
2) How will the panels look?
One common objection to solar panels is their aesthetics. Homeowners often feel traditional, blue-colored panels with silver frames stand out too much and may incur the wrath of neighbors. In fact, some homeowners’ associations don’t allow the installation of traditional panels because of a (potentially false) impression that they will lower property values.
In response to these complaints, many solar panel manufacturers now have black-panel options. Using black backsheets and black frames, these panels blend more easily into today’s traditional black roofs and appear more unique.
3) What role does
efficiency play in panel selection, especially on smaller residential roofs?
Solar panels all have an efficiency percentage, which measures the percentage of sunlight hitting the solar panel that gets converted into usable electricity. The greater the efficiency, the less surface area it will take for the solar panels to meet a home’s energy requirements—a critical criterion for builders who want to offset as much utility-generated power as possible using the smallest possible residential-roof footprint. To achieve the best return on investment, builders should seek panels within the 15-16% efficiency range or higher.
4) Have the panels been tested by a reputable, well-known third-party
firm that certifies the panels’ overall quality?
While the basic safety qualifications of solar panels are described in the Underwriters Laboratories 1703 standard, other important issues remain. Builders must determine how well panels will perform in specific environments. Have they been tested to survive mechanical loads resulting from wind and snow? How do they perform in the presence of potentially corrosive factors such as salt spray or blowing sand?
Quality solar panel manufacturers should document testing results for their product to show minimal power loss for all possible installation conditions, and builders should ask to see those documents to avoid purchasing subquality solar panels.
5) How good is the warranty?
The generally accepted life cycle of a solar array is at least 25 years, and panel warranties have generally coalesced around similar figures. Builders should insist on panels that have linear warranties, which guarantee homeowners specific energy production percentages for each of the 25 years of operation. For example, the manufacture might guarantee at least 97% effective energy output in the first year. By year 25, the panels must be producing at least 80.2% effective energy output. In addition, builders must demand a minimum of a 10-year guarantee on the workmanship and materials in the solar panels. After all, builders shouldn’t be liable for poor manufacturing practices by panel manufacturers—and that’s the peace of mind these warranties provide.
One caveat: Even high-quality solar panels can be undermined by mistakes made during
installation, so panel manufacturers often offer certification programs that train
builders and subs on the best practices for various types of residential and commercial installations.