Solar has become hot in Colorado with the rebates. Because of this many solar installer business have started in the past few years.
I got to speak with Cary Hayes from Rec Solar today on the phone and he mentioned something very interesting.
I believe he said that just a few short years ago Colorado only had about 18 solar installers in the Colorado and now there are over 100.
So when picking a Boulder solar contractor to install your system in the Colorado area you have many more to pick from.
I am sure the state of Colorado rebate program has been responsible for the explosion in contractors in the state.
But it brings up concerns when picking a contractor who just recently started in the business with his buddies. Are you going to get a guy that used to be a CPA installing your system with no experience? If you are, perhaps doing it yourself and following my blog might be an option. 
Ten things to keep in mind when choosing a solar contractor:
1) Experience…Choose a contractor that has long term experience in the market, has been operating for a number of years, and knows what they are doing!
2) Warranty….Choose a contractor that will provide a warranty for at least 5 years, ideally 10. Remember that the warranty is only as good as the company, so judge whether the company will be able to withstand a downturn in the market. Also, do they have warranty provision funding for potential issues?
3) Certification…Do they have NABCEP certified electricians on staff? Do they have master-electricians on staff?Choose a contractor with someone who is NABCEP certified, and has a master electrician.
4) Subcontracting…Do they sub-contract electrical or other work? Choose a contractor that does not sub-contract.
5) Price…Dont always choose the lowest bid. Smaller startups tend to underbid projects as they don’t realize what their costs are. Realize that you’re making a long-term investment that will be producing electricty for 25+ years.
6) Equipment….There is a large variety of different solar panels and Inverters to choose from…Don’t overthink this, as most are fairly simliar in output and price. Higher effciency panels will yield more power, but are more expensive.
7) Choose a contractor that “floats” the rebate and handles all the rebate paperwork and interconnection with Xcel Energy. This is a time consuming process, with many hurdles, so a customer should not have to handle this.
9)References….Good companies have happy customers. Get good references.
10) Dont wait! Xcel offers the largest rebate in the country, paying for nearly 60% of the cost of a PV system. These rebates will not last indefinetly, and I imagine we will see the first rebate “drop” from Xcel sometime in 2008 or early 2009….
Hope this helps!
Cary Hayes
Regional Sales Manager
REC Solar
http://www.recsolar.com
chayes@recsolar.com
303 815 0636