U.S. Department of Energy - Energy Efficiency and Renewable Energy
A Consumer's Guide to Energy Efficiency and Renewable Energy
Installing and Maintaining a Small Solar Electric System
 Electrical and building inspectors ensure that your system complies with standards.
Photo credit: Ken Olson.
Proper installation and maintenance of your small solar electric or
photovoltaic (PV) system is essential for maximizing its energy
performance.
Installation
When installing a PV system, there are many factors to consider:
Therefore, it's best to have a professional solar contractor install the system.
When choosing a contractor, ask yourself the following questions:
Has the company installed grid-connected PV systems? If not, has it installed grid-independent (or stand-alone) PV systems?
Experience in installing grid-connected systems
is valuable because some elements of the installation—particularly
interconnection with the local utility—are unique to these systems.
However, a competent company with off-grid
PV experience should not be eliminated just because it has not yet
installed grid-connected PV systems. Experience with off-grid systems
is valuable too, because grid-independent systems are more technically
complex than grid-tied systems.
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How many years of experience does the company have installing PV systems?
A contractor who has been in business a long time probably
understands how to work with customers and to compete effectively with
other firms. Additionally, he/she will probably be aware of the latest code and permitting issues surrounding the installation of PV systems.
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Is the company properly licensed or certified?
PV systems should be installed by an appropriately licensed
contractor. This usually means that either the installer or a
subcontractor has an electrical contractor's license. Your state
electrical board can tell you whether a contractor has a valid
electrician's license.
Local building departments might also require that the installer
have a general contractor's license. Call the city or county where you
live for additional information on licensing.
A solar rebate program may require that, in addition to being
properly licensed, installers must demonstrate that they have special
knowledge about installing PV systems. Special knowledge can be
demonstrated through certification by solar industry and/or trade
associations.
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Does the company have any pending or active judgments or liens against it?
As with any project that requires a contractor, due diligence is
recommended. Your state electrical board can tell you about any
judgments or complaints against a state-licensed electrician. Consumers
should call the city and county where they live for information on how
to evaluate contractors. The Better Business Bureau is another source
of information.
It is always a good idea to get more than one bid for the
installation of your PV system. Make sure that all bids are made on the
same basis. For example, a bid for a system mounted on the ground is
usually very different from another bid for a rooftop system.
Similarly, some PV modules
generate more electricity per square foot than others. Bids should
clearly state the maximum generating capacity of the system—measured in
watts (W) or kilowatts (kW). If possible, have the bids specify the
system capacity in "AC watts" (alternating current) under a standard
set of test conditions, or specify the output of the system at the
inverter. Also request an estimate of the amount of energy that the
system will produce on an annual basis (measured in kilowatt-hours).
Because the amount of energy depends on the amount of sunlight—which
varies by location, season, and year to year—it's unlikely the
contractor will quote a specific figure, but a range of 20% is
realistic. Bids also should include the total cost of getting the PV
system up and running, including hardware, installation, connection to
the grid, permitting, sales tax, and warranty.
Your warranty is also a very important factor for evaluating bids. A
solar rebate program may require that systems be covered by a two-year
parts-and-labor written installation warranty, for example, in addition
to any manufacturers' warranties on specific components (including
inverter and module warranties). The installer may offer longer
warranties. Also ask yourself, "Will this company stand behind the
full-system warranty for the next two years?"
Maintenance
As with any mechanical or electrical appliance, PV systems require routine, periodic maintenance. System components may also need repair or replacement from time to time.
An efficient and long-lasting system will depend on a periodic check
of system components and completion of any preventive maintenance as
necessary. Talk with your system installer about routine and periodic
maintenance. In the event of a system malfunction, effective
troubleshooting and repair is necessary.
You may be able to carry out many routine inspections and
maintenance tasks yourself. If, however, you are not the do-it-yourself
type, or if there is a major problem with your system, you will need to
locate a professional to do the work.
Learn More
Evaluation Tools
Financing & Incentives
Professional Services
Department of Energy Resources
Reading List
- Photovoltaic and Solar-Thermal Technologies in Residential Building Codes (PDF 1 MB).
(September 1999).
National Renewable Energy Laboratory.
Although geared toward the solar industry and policymakers, this
technical report provides a review of the building codes that affect
photovoltaic and solar water heating installations.
- Wiles, J. (December 1996). Photovoltaic Power Systems and the National Electrical Code: Suggested Practices (PDF 8.30 MB). SAND96-279. Albuquerque, NM: Sandia National Laboratories.
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