Solar panel manufacturers are doing a great job giving consumers a variety of panels to choose from. To some, solar panels are considered a commodity because they are often alike in size, power rating, and quality. Depending on your preferences, there are slight nuances you can pay attention to like cell type, efficiency, power tolerance, and warranty periods.

However, it is difficult to do research on your own on which modules are most aesthetically pleasing, environmentally sound, or best suited for certain environmental conditions. You should discuss your requirements with your solar installer who can suggest panels that will fit your needs. You will see a lot of good and bad information out there, and the panels you may be reading about may not be commercially available or feasible for your project. It is your solar installer’s job to educate you about the advantages and disadvantages of one panel versus another.

There are two resources I want to offer in sorting through the hype:

CSI’s List of Compliant Modules – This is a list of solar modules that meets the California Solar Initiative’s eligibility criteria testing. Most state rebate programs require that your equipment meet these requirements. You will see a STC power rating and a PTC power rating for each solar panel that is listed. STC, or Standard Test Conditions, is the power rating that is measured under laboratory conditions. PTC, or PV USA Test Conditions, is the power rating under more practical climatic and solar conditions. For that reason, the power output of PTC will always be lower than STC conditions. STC and PTC conditions will not account for all “real world” losses due to dust or dirt, temperature loss, DC and AC wire losses, and inverter efficiency.

Solar Design Tool – I think this is the best tool out there for evaluating solar panels. Did I mention it’s free? You can’t beat that. You can select up to 7 different models for a side-by-side comparison of 27 different criteria. I’m not sure how often new solar modules are added, but I’ve had little trouble finding what I’m looking for. The only deficiency with the tool is that they are sometimes behind with the “CSI listing” field. I suggest you go to the previous site to see if a module is CSI compliant.

Brightstar Solar is a licensed solar installer in Massachusetts and Connecticut. We work with residential, commercial, and public customers to maximize incentives, navigate the installation process, complete grant and rebate paperwork. Please reach out to us you are interested in a complimentary solar evaluation of your home, business, or institution in Massachusetts or Connecticut.