States establish licensing requirements for contractors in order to protect consumers from unsafe practices and protect the reputation of the industry, as improper installation may create safety risks or result in poor equipment performance. Licensing is distinct from certification. While licensing is mandatory for certain practices, certification is a voluntary standard that installers attain to differentiate themselves from competition and to instill confidence in consumers. Certification may entail completing coursework, installing systems for a certain period of time, or taking an exam, but it is typically not required to install equipment.
The North American Board of Certified Energy Practitioners (NABCEP) is a nationally-recognized, independent, voluntary certification program for photovoltaic (PV) and solar-thermal system installers. To become NABCEP-certified, installers must attain at least one year of installation experience and must document all training and installations. Installers must also pass a rigorous exam, sign a code of ethics, and take continuing education courses for re-certification every three years.
Licensing and certification have different advantages and disadvantages. From a financial point of view, voluntary national certification is preferable to mandatory state licensing because it results in a lower cost of installation and provides greater consumer choice than mandatory licensing. In states that do not require solar contractor licensing, certification can provide a baseline level of quality. State licensing may be restrictive, as state licenses do not typically transfer, so geographic mobility is limited. However, state licensing can protect consumers from potential safety hazards and will help ensure that systems are installed properly. While both licensing and certification have drawbacks, requiring solar contractors to be licensed or certified is preferable to no quality control of system installation and will result in baseline standards being met, which will in turn lead to higher consumer satisfaction.
Status & Trends
Solar contractor licensing commenced in the 1980s alongside the introduction of incentive programs for solar water heating. State regulation and licensing of solar contractors continues to evolve as the industry grows. Currently, 12 states and Puerto Rico have solar contractor licensing requirements. The contractor licensing requirements described here refer to solar-specific licensing requirements, rather than general electrical or plumbing contractor licenses. Most states require a licensed electrical or plumbing contractor for PV and solar-thermal systems, respectively.
Some states require solar installers to obtain a separate, specialized solar contractor’s license. In most cases, solar is a specialty classification under the general electrical or plumbing licenses and all appropriately licensed contractors can install solar systems without the solar specialty license. However, contractors can obtain the solar specialty license and install systems without having the full electrical or plumbing license. This reduces the cost of licensure for contractors who only install solar systems.
Even in states that do not have contractor licensing requirements, financial incentive programs often include installer requirements, such as pre-approval or, some cases, NABCEP certification. Although intended as a voluntary, value-added credential, NABCEP certification is now either mandatory or preferred for contractors who seek to install systems eligible for state incentive programs. For example, to be eligible for state rebate funds in Maine, Minnesota or Wisconsin, a PV system must be installed by a NABCEP-certified professional. California, Delaware and Massachusetts rebate programs prefer or recommend NABCEP-certified professionals. In Utah, NABCEP-certification is a prerequisite for qualifying for a state solar contractor license.
In the absence of state licensing or certification requirements, local governments may adopt regulations or establish their own licensing procedure. For example, Madison, Wisconsin, and Austin, Texas, have acted in advance of their state governments by adopting solar contractor licensing and/or certification requirements.
For solar-electric systems installed in the United States, nearly all aspects of licensing are governed by the North American Electrical Safety System. Many organizations, however, are involved in developing product codes and standards, testing, and approvals, such as these:
Solar Licensing Database. Pat Fox, Interstate Renewable Energy Council, Inc. (IREC), July 2010.
Credentialing: What's in a Name? A Lot. Jane Weissman, Solar Today, October 2009.
The Qualified Solar Installer. Jim Dunlop, Solar Today, October 2009.
Costs and Benefits of Practitioner Certification or Licensure for the Solar Industry. Interstate Renewable Energy Council, Inc. (IREC), May 2002.
 Costs and Benefits of Practitioner Certification or Licensure for the Solar Industry, IREC, May 2002.
 Solar Powering Your Community: A Guide for Local Governments, U.S. Department of Energy, January 2011.
Disclaimer: The information presented on the DSIRE web site provides an unofficial overview of financial incentives and other policies. It does not constitute professional tax advice or other professional financial guidance, and it should not be used as the only source of information when making purchasing decisions, investment decisions or tax decisions, or when executing other binding agreements. Please refer to the individual contact provided below each summary to verify that a specific financial incentive or other policy applies to your project.
While the DSIRE staff strives to provide the best information possible, the DSIRE staff, the N.C. Solar Center, N.C. State University and the Interstate Renewable Energy Council, Inc. make no representations or warranties, either express or implied, concerning the accuracy, completeness, reliability or suitability of the information. The DSIRE staff, the N.C. Solar Center, N.C. State University and the Interstate Renewable Energy Council, Inc. disclaim all liability of any kind arising out of your use or misuse of the information contained or referenced on DSIRE Web pages.