How do I select the right equipment for my solar system?
Many customers who have decided to go solar face their first hurdle in selecting the right equipment for their PV system. As with any selection process involving multiple options, you want to be well informed about what each option has to offer. Solar equipment is no exception, but it is a lot easier that you might think. We put together the following guide to help with your selection process of residential solar panels and grid tie inverter.
Choosing Residential Solar Panels
When it comes to residential solar panels, the technology has reached a point where all products, as long as they come from a reputable manufacturer, will perform well on your roof. Though there are a number of options to choose from, the final decision comes down to personal preference.
Monocrystalline vs. Polycrystalline Residential Solar Panels
This a never-ending debate, and the bottom line is that efficiency only matters when space is extremely limited, such as a sailboat. It is well known that monocrystalline cells are more efficient than polycrystalline cells, but poly cells have come a long way in closing the gap and making the difference almost negligible.
Some people believe that a polycrystalline panel produces less power than a monocrystalline panel, but that is not true. A solar panel rated at 300W will produce energy at the rated power regardless of the type of cell that it uses. The only difference in this case is that a monocrystalline panel might be smaller in size.
As to which one performs best in overcast weather – the short answer is that monocrystalline cells tend to perform better in low-light conditions. That being said, it does not mean that polycrystalline cells are bad performers, and for practical purposes the differences between the two are almost negligible.
USA-made vs. Overseas Residential Solar Panels
This one is entirely personal preference. If you are dedicated to using locally manufactured products, you will opt for panels made in the United States. If you are willing to pay a premium price, you are guaranteed to have one of the best solar panels ever made, and depending on where you live, you might qualify for additional incentives.
Residential solar panels made in megawatt factories overseas, mainly in Asia, are not consumed in their country of origin: they are shipped to countries with high PV demand. In order to sell their panels, manufacturers have to meet local requirements for quality and safety. If you are in the United States and you buy a panel made in, for example, Vietnam, the chances are that the same panel will meet European standards as well as the American requirements, so the quality should not be a cause for concern.
When buying Asian-made solar panels, we recommend looking for two things: a major manufacturer of Tier 1 modules that sells large quantities of panels globally, and a manufacturer with offices and inventory in the United States.
Black or Non-black Residential Solar Panels
The color of a solar panel is entirely dependent on your personal preference. Monocrystalline cells are darker—bluish-gray or sometimes close to black; polycrystalline cells lean towards the blue color, with multiple crystals reflecting different shades of blue. The cell color cannot be selected or changed, but you can select the color of the aluminum frame and the back sheet (which is the background color behind the solar cells).
The frame of the panel comes anodized in natural aluminum or black. To improve the aesthetic appearance, most residential panels now come with black frames. When people refer to an all-black or a Black-on-Black (BoB) solar panel, they are referring to a panel (usually monocrystalline) with a black aluminum frame and a black back sheet. An all-black solar array, where the mounting rails and hardware are also black, tends to blend more effectively with the roof and is preferred among homeowners who are more particular about the appearance of their roof. The black finish adds cost to the final product, so large panels for commercial applications come with an aluminum-colored frame and white back sheet, given that they are usually installed out of sight.
One point worth mentioning is that residential solar panels with black back sheets operate at a higher temperature, therefore losing efficiency. The loss is not significant, but it will increase the operating temperature of the array, especially in hot climates. If efficiency is your ultimate goal, a white back sheet is recommended, though an all-black panel is not a bad tradeoff when appearance matters.
Selecting the PV Inverter(s)
Selecting the appropriate inverter or inverters in a PV system plays a more important role than the solar panels. It is the piece of equipment that makes the greatest difference to the performance of your system.