The short answer is yes; except that owners of single-family homes doing work on their own dwellings are exempt.
Recently the Board considered this issue and concluded that SPV systems, including the SPV panels themselves, to the extent that they are used for the generation, transmission, or utilization of electrical energy, constitute electrical work within the meaning of the Act.
Therefore, unless work was exempted by statute (e.g. operates at less than 10 volts, etc.), a contractor is required to obtain a license and business permit issued by the Board to install, erect, and repair, etc., SPV systems including SPV panels themselves.
To read the Excerpt on SPV Systems from the Spring 2010 Construction Code Communicator click Here.
To view the Spring 2010 Issue of The Construction Code Communicator click Here