For disclosure and so you know where I am coming from: I am a Civil Engineer by training, spent two years managing a renewable energy installation company in Northern Nevada, followed by a general contractor focusing on green building and energy efficiency. I have since moved on to become a program manager the Nevada Institute for Renewable Energy Commercialization, a 510(c)3 nonprofit organization. Alright, lets get to it:
First thing is first, don’t even consider installing Solar until you have made your home or business more energy efficient (see my post from last week about how to do this yourself). Energy efficiency is often the lowest hanging fruit with the quickest bang for your buck, and every dollar you save is a many more dollars you don’t have to spend on Solar. While they often cost a few hundred bucks, you can also consider a home (or business) energy audit to expose your areas of greatest concern; that lowest hanging fruit.
The most important thing today when considering installing solar is to be an informed customer. I have seen too many people of the past five years be taken advantage of by shysters in the industry looking to make a quick buck on the uninformed with hard sales tactics and brutal lies. I have found from firsthand experience that if your installer is straightforward and honest, the sales cycles is often about 6 months. These means from a customer perspective from the first time you talk to someone about solar, until the time you feel comfortable about going forward with it can be six months. Solar has become a full technology industry and installing a system is a sizable investment for anyone requiring an objective financial decision as well as the emotional desire to do so.
When selecting your solar installer, make sure you get at least three estimates. Here are the most important due diligence questions to ask before you make a final decision…
Dan’s “10 Questions to Ask Your Solar Installer”:
- Are you licensed, bonded, and insured as an electrician or solar installer in the state?
- Are your installers locally licensed if required (such as Nevada OSHA PV License in Nevada)?
- Are you NABCEP (North American Board of Certified Energy Practitioners) PV Installer certified?
- What size systems can I actually fit on my roof?
- What brands of solar modules and inverters will you be using on my system? What are their warranties (expect 10+ year inverter warranties and 25-30 year power performance guarantees of 80%+ on the modules as well as a 2-year workmanship warranty)?
- Can you show me some systems that will be similar to mine that you have installed before?
- Do you finance solar projects or offer a solar lease? Can you get my payments less than my current monthly electricity costs? If not, what are my upfront costs and what does my return cash-flow look like?
- Is my roof in good enough shape to last for the life of the solar system (25-30 years+)? Do I need to re-roof beforehand?
- Will you help me understand and secure rebates & tax incentives? Can you help me finance or roll these cost savings into my financing package from day one (so that I don’t have to pay anything more out of pocket upfront)?
- What are my additional expenses over the life of the system? Will I need to replace the inverter(s) in 7-10 years? Do you cover that?
If you are looking to dig into this a little more, the National Renewable Energy Labs have some good consumer resources:
- A Consumer’s Guide: Get Your Power from the Sun (Brochure) – NREL
- Own Your Power! A Consumer Guide to Solar Electricity for the – NREL
- PVWatts – The Industry Standard for Estimating Energy Production- NREL
While I am no longer managing a solar installation company, if I can be of any assistance in helping you make a decision I invite you to connect with me on LinkedIn, Twitter, via a comment below. Thanks! – Dan
DanHerr.com 
Good information Dan. Solar is a great way to go as long as you’re informed. As for the energy efficiency optimization prior to going big, I totally agree. Conserving energy is the home is easy picking for a lot of folks, as long as they know how to do it!
http://www.enerdigs.com
Hi Dan. Great questions! I plan to ask these along with a slew of others. I have a quote for 245W poly solar panels. Do you recommend I ask the vendor if mono solar panels are a better way to go? For me, the fewer panels I would need the better, but I also don’t want to sacrifice performance or efficiency. What has been your experience?
Hi Rose,
Thanks for your question. In my experience the bigger questions than monocrystalline or polycrystalline have to do with the power density that you are getting (watts per square foot) and the cost you are paying for it (cost per watt). Most modules from respectable installers come UL rated, factory tested with 25-year power performance guarantees, and with workmanship warranties from the installer. That said, if space is the biggest issue, it might make sense to go with a higher wattage module, though it will likely mean not only a higher cost per module, but also a higher cost per watt (meaning higher overall system cost). After that it is just a matter of making sure they install them properly (wired properly, on the right pitch, with the right standoffs and including room for proper air flow below the modules) to ensure to ensure maximum performance of your system. Hope that helps!
-Dan
Thanks so much for your response! It really helps!
Sure thing!
I have a 3 year old 4.5 kw system, I’d like to expand it. How much would it cost to add panels to say make it a 6.5 kw or better system. I understand I many have to upgrade my inverter to accommodate the extra 2kw. Thanks
Joe, Thanks for your question.
In general it will be better to have any new array on a separate inverter or at least as a separate string on a new inverter, but since I have been out of the solar PV industry for a while now and technology tends to rapidly evolve, it would be best to work with a local NABCEP-certified PV installer who can make sure to get you all setup. I believe costs have gotten down around $5.0-$5.5/Watt at the most for smaller residential solar PV (not including the inverter upgrade), but check out this website to find someone local who can give you prices and details about how to upgrade:
http://www.nabcep.org/certified-installer-locator
All the best!