U.S. Department of Energy Energy Efficiency and Renewable Energy

Ask an Expert

May 10, 2013

I have a high efficiency 6-panel awning mounted array. I'm from Maine so the tilt angle is fixed at approx. 38 degrees. If I adjusted the tilt to maintain a 90 degree angle to the sun, what would be the annual % solar gain? -Marc

SunShot Solar Outreach Partnership

The SunShot Solar Outreach Partnership has been tasked with helping accelerate adoption of photovoltaic (PV) solar at the local level by providing timely and actionable information to local governments.


Because our program is publicly funded, we are unable to recommend a specific installer, company, or service. We can, however, provide a few tips you may find useful in locating an experienced solar professional in your area.

Choosing a contractor for installing solar heating systems, solar photovoltaic (PV) modules, or both can be a time-consuming process. However, this process is often necessary in ensuring you find a provider that meets your needs. In choosing a solar installer, there are a couple of steps you can take to make sure the company you decide to work with is right for you:

Get multiple quotes from several contractors. Make sure these quotes specify the payback period of the investment will be, as well as expected energy savings each month and over the lifetime of the system. These quotes should also be comprehensive, representing the total cost to you of the equipment, permit and interconnection fees, installation labor, and any additional products and services obtained from the contractor. Installers you contact should be familiar with the wide variety of financing options available in your state and must be able to explain the differences between these alternatives.

  • Ensure installers have the proper professional credentials. Organizations such as the North American Board of Certified Energy Practitioners (NABCEP) offer certifications for both PV and solar heating installers, as well as for technical sales staff. In addition, any connection work should be performed or checked by a licensed electrician (for PV systems) or a licensed plumber (for solar water heating).
  • Make sure installers have the right kind and right amount of insurance necessary to protect you from liability in the rare event that an accident occurs on your property during installation.
  • For non-certified installers, make sure they have adequate hands-on experience in installing the system you desire. Solar professionals who have worked on 3-5 installations are typically deemed experienced. Formal training in solar, such as the programs offered by many community or technical colleges across the nation, may also be a deciding factor in choosing an installer.
  • Protect the quality of your system and value of your investment by inquiring as to the warranties that apply to the solar equipment to be installed on your property. Most reputable companies offer warranties that guarantee a minimum level of system performance for 25 years.
  • Check consumer reviews. Online portals such as the non-profit Better Business Bureau’s website and a number of popular privately-owned review sites may allow you to factor in the experiences of others into your contractor selection process.

For more detail on these and other tips, please read the following articles by the Georgia Solar Energy AssociationSolar AmericaClean Edison, and Renewable Energy World.

To help you get started, a list of companies that install solar water heaters for homes and businesses in New York can be found here. NABCEP also provides a free online tool that allows users to find local certified solar professionals.

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