A solar DB box has bypass diodes that keep the energy flowing in one direction and prevent it from being fed back to the panels. Frank Rosenkranz, solar energy product manager for EMEA, India, and the Americas at the connector and solar distribution box company TE. As the modules have changed, the junction box has maintained the same functionality. But now, with higher power outputs and voltages, junction boxes have had to improve their ability to protect that power. The overall role of the junction box has remained the. The rapid rise in popularity of bifacial modules meant that junction box designs had to be updated on the fly. Other sudden updates to solar systems include a quick shutdown and.