Interested in High-Power Rooftop Solar Panels for Your Home?

If you’re a homeowner replacing your roof, are you considering rooftop solar panels? If so, the solar installer you hire will develop a comprehensive design plan that includes how many panels your array will have, type of panel, solar array positioning and mounting system.

Learn about the pros and cons of high-power rooftop solar panels.

With improvements in solar technology, homeowners often ask about the importance of having high-power rooftop solar panels for their home. This article focuses on why an installer might recommend high versus low-wattage panels.

Solar panel roofing system on a home.

What factors go into designing rooftop solar panels?

When installers design a solar array, they evaluate all the elements that will achieve the desired results. Some key objectives are high overall performance, the appropriate output, and maximum efficiency. Factors considered when making design decisions for high-power rooftop solar panels include roof space, the amount of direct sunlight, load-bearing capacity, local weather patterns, state or local requirements, and your budget.

After evaluating these and other relevant factors, the design work begins.   

What is a high-power versus low-power rooftop solar panels?

The two most popular brands of solar panels on the market are QCells and REC. As an example of relative size, we can look at two panels that Golden Group offers from the two most popular brands, Qcells (lower wattage) and REC (higher wattage).

What’s interesting is the figures below show that while the Qcells panel has less wattage than the REC panel, they have nearly the same efficiency. The lower wattage Qcell panel is also relatively smaller and lighter than the REC panel.

Here are the exact numbers: 

Lower Wattage (Qcells):

Power: 425 watts
Efficiency: 22.5%
Size:  44.6″ x 67.8″

Higher Wattage (REC)

Power: 460  Watts
Efficiency: 22.6%
Size:  47.4″ x 68″

 

Here’s the question: If the low-power and high-power have the same efficiency, why would you choose one over the other? The answer is that there are pros and cons for each, depending on the factors above, as well as others. We’ll discuss each of these factors below.     

Power output and energy efficiency

Higher-wattage panels can generate more electricity per unit area, which is beneficial if the roof has limited space or you want to maximize the energy production of your system. Less space-efficient lower-wattage panels may need a larger area of unshaded roof surface for the number of panels needed.

Installation Costs

Lower-wattage panels have a lower upfront cost per panel. However, you may need more of these panels to achieve the same power output as a system with higher-wattage panels. Other increased costs may include more complex wiring and mounting systems. The upshot is that the lower upfront cost per panel of the low-wattage panels can make them more accessible for those with a limited budget.   

Aesthetic appeal

High-wattage panels may give an array a more streamlined look, especially if the roof space is limited. If you have an HOA, they may have specific requirements for appearance.

Space-efficiency

Lower-wattage panels are less space-efficient than higher-wattage options, which makes a difference with a smaller roof. The number of panels needed to meet your energy needs may require a larger area of unshaded roof surface.

Weight

The size and weight of higher-power panels can be a challenge for roofs with space and weight restrictions.

Performance in shaded conditions:

Higher wattage may experience more significant power losses in shaded conditions, as the shading of even a small portion of the panel can have a greater impact on overall output. With lower-power panels, each panel generates less power, making the impact of shading on the overall system output less significant.

Flexibility  

Because of their smaller size, lower-wattage rooftop solar panels offer greater flexibility in system design. It lets the installer customize the size and configuration of the solar array to better fit your roof space and energy needs.

Regulations and Requirements

The solar installer must be compliant with any regulations regarding residential solar arrays, which are primarily for safety purposes. For example, requirements from the International Residential Code (IRC) include “access and minimal spacing shall be required to provide emergency access to the roof, to provide pathways to specific areas of the roof, provide for smoke ventilation opportunity areas, and to provide emergency egress from the roof for roof access, pathways and setbacks. The Massachusetts Comprehensive Fire Safety Code has its own set of regulations for access pathways and setbacks at the roof ridge. Local municipalities and HOAs may have additional requirements.

What type of rooftop solar panel is most appropriate for your home?

The solar installer will consider all the factors above when designing your system. As the homeowner, it pays to educate yourself about the basics. Before making a decision, take the time to consider the installer’s recommendations, the short-term costs, long-term benefits and trade-offs between lower and higher wattage panels.

Not all solar installers are the same

Look carefully into an installer’s reputation and skills before signing an agreement and moving forward, especially since there’s no official certification for solar installation. Poor design, low-quality materials, lack of experience, or sloppy installation can negatively affect long-term performance.

Another issue is that few solar installers understand the roofing surface and structure, which can lead to punctures, potential leaks, and repair costs. If you don’t notice these problems until well after the solar installation is complete, it’s unlikely your installer will address and pay for roof damage—or they may blame the roofer.   

Hire the roofing and solar installation experts

Because your roof and solar panels must be integrated, it makes the most sense to re-roof your home and install solar at the same time, as a single home improvement project. 

Award-winning Golden Group provides top-level expertise in both roofing and solar installation. Homeowners have the benefits of working with a single company that understands both your roof and solar energy systems. We know how to install your solar array so that your roof is safe, and should you have questions or concerns, our top-rated company is there for you upon installation and in the long run.

Call Golden Group Solar today at 508-873-1884 or click here to conveniently contact us online.