In April, we provided a list of ten questions every prospective solar system shopper should ask of PV contractors. Below are the answers to those questions along with some helpful advice from Sunetric Energy Consultants.

1. Do you have a contractor’s license?
   Any solar company that claims the ability to do more than simply sell you a solar system should be able to provide you with their contractor license number. Sunetric's contractor license number is HI LIC # C26505.
2. Does the company also hold a C-13 (Electrical Contractors) license? 
   Among other license classifications, Sunetric has holds a C-13 Electrical Contractor's license. This means that our employees are licensed to install solar photovoltaic systems. Many companies in Hawaii hold a C-61 license, but this only allows for the legal installation of solar hot water systems. Sunetric is proud to be one of only a few companies in Hawaii to hold a C-13 Electrical Contractor's license.
3. Does your company sub-contract out work to a C-13 license holder?
   While most of the solar companies on the islands require the use of sub-contractors to perform the design and installation of the systems that they sell, Sunetric takes pride in being one of few fully integrated solar companies in Hawaii with over 80 employees who are experts in their respective fields. As such, we are able to provide our customers with incredibly efficient turnarounds on installations, as well as unparalleled maintenance and support.
4. Who provides the warranty on the system?
   At Sunetric, all of our experts are in-house. Meaning, if any warranty issues arise we are the go-to resource, there is no confusion. Alternatively, if you choose a company that contracts out others for design and installation, as your system ages you will be dealing with multiple companies under varying obligations and circumstances.
   
   Unfortunately, with this second scenario, responsibilities can become clouded (or avoided) and the issue you’re attempting to resolve may end up falling through the cracks in the process.
   
   Ideally, it is best to purchase a photovoltaic system from an experienced company that not only acts as a salesman or broker, but one that also designs, installs and guaranties the warranty themselves. And, at an absolute minimum, your PV contractor and their sub-contractors should have survived at least one full warranty cycle to prove that they’ll be there after the sale if you need them.
5. How many PV systems has your company sold/installed (excluding solar hot water systems)?
   You can tell a lot about a PV contractor with this question. A very important consideration of your purchase should be the level of experience that your vendor has in the marketplace. The greater the number of installations and the greater the variety of projects, coupled with the least amount of complaints, the greater the trust is that the company deserves.
6. Can I get references from a few of your past customers? In addition, are you registered with the Department of Commerce & Consumer Affairs (DCCA), the Better Business Bureau and the Professional and Licensing Division of the DCCA? Has anyone filed complaints against you with these entities?
   These credentials should be basic requirements for any PV contractor that you decide to work with. These consumer organizations are looking out for your best interests, and any company that is not aligned with these organizations is not worthy of your consideration.
7. What is the contractor’s warranty on labor?
   Sunetric offers a five year warranty on all workmanship that is performed on all of our installations. Be sure that whomever you work with for the installation of your PV system, at the very least, provides the state’s minimum one year of protection.
8. Can you provide me with cost broken down into both DC and AC Watts?
   The technical aspects of this question can be confusing, but it is very important to at least understand the basics. Start with your electric bill - the kilowatt hours you are charged for are based on AC Watts (the alternating current available at your household outlets). PV panels convert solar energy into DC Watts. To convert that DC power from the panels to AC power at your outlets, a PV system utilizes a power inverter (or multiple micro-inverters in series). When this conversion happens, there is always some power loss, generally around 20%. This power loss is why it is vital to know both the DC and AC Watts the system is designed to produce – because if you are told the specified system is designed to offset your entire electric bill, and you only see DC Watts, you may be left with 20% or more of your bill left to pay every month!
9. Can you provide me with an equipment list, breaking out the cost of labor from the cost of materials?
   As you are cross-shopping PV contractors, huge disparities in the cost portion should be red flags to ask further information about what exactly you are getting for your money. This allows for the ability to compare not only price, but the actual value that is being delivered by the company that is proposing a given PV configuration to you. For the simple fact that the overhead is required by a company to ensure you receive excellent customer service, superior-grade components & hardware, and complete warranty assurance are costs that a high-quality organization must absorb. A very low price that you find within an otherwise similar group of bids can be an indicator that you are purchasing either inferior products or inferior support. 
10. What formula do you use to calculate in kWh (kilowatt hours) the production of the PV system?
    Example.
    
    John has a 3kW system. He lives in a 500 zone, which has 5.81 sunhours. 3kW x 5.81 hours x 77% efficiency at the inverter  = 13.42 kilowatt hours (kWh)! Easy!
    
    So, at the end of the day. If you want kWh's, multiply DC kW by the appropriate sun hours, then multiply the result  by 0.77.
    
    Here's a Conversion of SunZone to Sunhours:
    500 -> 5.81 Hours (Yearly Average)
    450 -> 5.23 Hours (Yearly Average)
    400 -> 4.65 Hours (Yearly Average)
    350 -> 4.06 Hours (Yearly Average)
    300 -> 3.49 Hours (Yearly Average)