5 Questions to Ask Before Purchasing a Solar Electric System

by Shawn | 13 Comments

This is an edited excerpt of an article originally posted on AOL Real Estate written by Audrey Tempelsman. Audrey asked me to help her on an article you can read in full here.

There are a nerve-wracking number of solar manufacturers and installers out there, so I caught up with Shawn Roe of SRoeCo Solar, a solar advice service, and asked him to share five questions that all consumers should ask before purchasing a system. I hope you’ll find his insight as helpful as I did:

1. “How many systems has your company installed?”
Due to the recent spike in solar panel installations, and the decrease in other construction-related businesses, many roofers, fencers, and builders are attempting to start solar installation companies with no solar experience and without proper solar installation knowledge. Look for a reputable installer with at least 50 installations and a few references.

2. “Is the warranty on my solar panels 25 years?”
Most solar panels on the market are high-quality and will have a guaranteed output of not less than 90% after 10 years and no less than 80% after 25 years. Any brand panel should have this warranty, whether it’s made in China, Germany, or America.

3. “Is the warranty on your labor 10 years or longer?”
Some states require installers to warranty their labor for 10 years in order for the system to be eligible for state rebates. Any good installer should have no problem including this.

4. “How many kilowatt-hours will the system produce the first year?”
This is arguably the most important factor in comparing solar electric systems (other than price, of course). If you have solar panels warranted for 25 years, and labor guaranteed for 10, then the brand of solar panel – whether Canadian Solar, SunPower, Suntech, or any other – doesn’t matter. The only thing that matters is how much energy they are expected to produce in a year. Many times the cheaper, “less efficient” solar panels will produce more energy in a year at a better price than the pricier, “more efficient” solar panels. When warranties are the same, output is the money-maker, not brand or efficiency.

5. “How much will it cost? (…after parts, labor, installation and rebates)?”
Don’t compare the cost of the panels exclusively, or the labor exclusively. Compare the bottom-line cost after rebates. Whoever can give you the most output (kWh/year) at the best price, is the company you should chose. This is what I call ‘solar value’.


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  • Great Article, The only thing is question #1 – to find a company in my area that has 50 installations under their belt would be impossible, very, very few installation companies have those kind of numbers. I personally have 2 and one of them was my own. Also I would ask what type of education and/or certifications you have, IREC, ISPQ, NABCEP etc., and who is the licensed electrical contractor in charge. In NY you must be NYSERDA eligible installer to get the rebate from them and you must have a licensed electrical contractor to sign off on the work. Good work Shawn, way to keep it green, best of luck and Happy Holidays to all

  • Good point Rich. I was considering it from the California point of view, where there are more installers with over 50 installations. Thanks for sharing the NY perspective. Also, you’re right that people should ask about an installer’s certifications. Make sure they have (at the minimum) the necessary licenses to be eligible for the relevant rebates.

    SRoeCo Solar

  • Dave

    from #4 above “Many times the cheaper, “less efficient” solar panels will produce more energy in a year at a better price than the pricier, “more efficient” solar panels.”

    why? and is there a formula? some installers I am getting quotes from say it is 100% of the KW of the system, others say 110%. is there a way to figure this out on my own without relying on the installers estimate, which may or may not be based on fact.

  • Gerard

    To maybe give a little insight on your question Dave is that the different solar technologies provide differing solar capture properties and efficiencies. Crystalline (Mono, Poly) as far as I know produce the most energy in a least amount of space, but have great inefficiencies when under great amount of heat. Thin film solar panels are less efficient than crystalline cells but handle heat much better and perform better under indirect sunlight than crystalline cells. I would usually consider using crystalline modules in space restricted areas such as residential roofs and use thin film for areas plentiful in space such as industrial/commercial roofs.

  • Would it be cheaper for small 1 person business to do it yourself? I am a retired steamfitter and have the ability to do all labor and purchase all items needed. Any suggestions for me what type system I should use here in sunny I repeat SUNNY BAKERSFIELD CALIFORNIA?

    • It definitely could be cheaper for a DIY solar project, at least financially. Obviously, it will cost more time, energy, and effort. The major issues would be:

      – properly designing the system for your specific needs (size, shading, space)
      – conforming to state and local interconnection laws (usually a certified electrician must connect the system to the utility meter, some areas mandate certain racking/bolts, others mandate the opposite)
      – purchasing the correct balance of system (wires, racking, anchors, solar connectors, etc)

      One compromise would be to contact a local installer and ask for help with a DIY solar installation. Ask for a full-installation quote. Then, tell them you want to install it yourself and ask the price for ALL the materials (panels, inverter, and balance of system) but minus the labor if you DIY.

      If you choose to DIY, then ask for one lead installer/electrician to come out for 1-2 hours to inspect your work, and connect the system to the utility meter. I’ve heard of homeowners paying $200-300 for the installer to double-check their DIY install, and ultimately saving a few $1,000 on the total installation. That’s my recommendation.

  • herb

    what about 110 w dupont panels here in townsville @horan &bird they are producing at least 10%more than 6 other panels?

  • Don Chandler

    Great article – it really cleared up much of the ‘confusion’ I encountered with my first solar company rep.
    Many thanks for the research.

  • Zeke

    Am considering putting panels on ground. Living in the desert, heat can reach highs of 110 degrees in summer. Are mono panels good for this environment?

  • Another very important question is for how long do they have been in business of installing solar panels. !0 years warranty means nothing if they do it foe few months.

  • whoopsOhMy

    @AWS Solar. Your answer is “poor marketing” and not an approach of integrity.

    Installers come and go, its the Panel Manufacturer’s panel efficiency and output, warranty and longevity that is important.

    Additionally what is the output efficiency of those panels for performance degrades approximately 1/2 % per year that is what is not told to consumers- a cheaper less efficient panel requires more panels which means the consumer is paying more

    And,… the payback to break-even on solar panels is between 15-20 years, with a life expectancy of 20-25 years. That equates to this: When the life expectancy is reached the consumer has recouped their investment; time to buy new panels

  • @@whoopsohmy:disqus you mention” a cheaper less efficient panel requires more panels which means the consumer is paying more’,
    an 6KW solar system can be made by 20 solar panels of 300W or a 24 panels of 250W, the output will be the same, the only difference will be the surface covered by solar panels. An system of 250W will require more 70 sqft of roof space. Performance degradation 0.5-1% it is similar with gas mileage for a car , with time mileage/ gallon will drop.
    In California break-even on solar panels is 5-10 years and life expectation of 25-30 years on good panels.

  • walter

    Watch how many of these companies backup their output efficiency warranties over the years, they will come up with every excuse. You didn’t clean them everyday, watch! No thanks!