These cabinets store excess solar energy, 2. provide backup electricity during outages, 3. contribute to environmental sustainability. . What is a solar photovoltaic grid-connected cabinet? A solar photovoltaic grid-connected cabinet is a specialized enclosure that houses the essential components for integrating solar power systems into the electrical grid. A poor choice can result in failed inspections, delayed connections, and unexpected retrofit costs. Such cabinets act as the “nerve center” for residential or small-scale. .