In order to obtain one of these specialty licenses, installers must meet the following criteria. The applicant for a Restricted Solar Mechanic license must provide the Arkansas Department of Health with evidence of relevant training and experience with plumbing related to solar water heating systems. Applicants for a Restricted Solar Mechanic license must have served four years as a registered Restricted Solar Mechanic Trainee. Applicants for a Supervising Solar Mechanic license must have at least five years of solar mechanic plumbing experience or its equivalent, with a least one year as a licensed Restricted Solar Mechanic. In order to progress towards a Restricted Solar Mechanic license, Solar Mechanic Trainees must register with the Department of Health to document the training and experience gained.