An apparatus includes terminals configured to be coupled to a string wiring of a photovoltaic string. The apparatus also includes a power controller configured to control a power provided over the string wiring by a photovoltaic panel in the photovoltaic string. The apparatus further includes a wireless radio configured to at least one of transmit and receive wireless signals using the string wiring as an antenna. The wireless signals contain data associated with the photovoltaic panel and/or the power controller. For example, the wireless radio could be configured to receive a first signal containing a command for the power controller from the string wiring and to provide the command to the power controller. The wireless radio could also be configured to receive an acknowledgement associated with the command from the power controller and to transmit a second signal containing the acknowledgement over the string wiring for wireless transmission.