How a solar system works, component by component

They sit on opposite sides of the inverter and do the same job for different current. The DCDB is the DC distribution box between the panels and the inverter: it combines the array strings and houses their isolation and surge protection. The ACDB sits between the inverter and your building supply, protecting and isolating the AC side. A quotation with one and not the other is worth questioning.

No, and they are not interchangeable. A surge protection device handles overvoltage (a transient spike, typically from a nearby lightning strike or a switching event) by diverting that energy safely to earth. A miniature circuit breaker handles overcurrent, disconnecting the circuit when too much current flows, as in a short circuit or an overload. Different fault, different device. A system needs both.

Two other things that matter. It runs maximum power point tracking, continuously adjusting the electrical load it places on the array to extract the most power available under current light and temperature. The array does not simply produce a fixed output. And it performs grid protection functions, including anti-islanding: if grid supply fails, the inverter must disconnect rather than energise dead lines. That safety behaviour is why a standard on-grid system goes down in a power cut.

They are designed for the conditions: touch-safe when mated so live DC terminals are not exposed, weather-sealed against years of rain and UV, and locking so vibration and thermal cycling cannot work them loose. A poor DC connection generates heat, and heat in a connector on a roof is a fire risk. Connectors are also the classic place a cheap installation saves money invisibly, including by mixing brands that superficially fit but were never designed to mate.

An ordinary meter counts electricity flowing one way, into your property. A net meter is bidirectional: it keeps separate running totals for units imported from the grid and units exported to it. Installing one is a DISCOM process (TGSPDCL or TGNPDCL in Telangana; APSPDCL, APEPDCL or APCPDCL in Andhra Pradesh, depending on which one supplies you) rather than something an installer simply fits, and it is the piece of equipment that turns generation into a bill reduction.

It is the part carrying every wind and weather load on the array into your building for the next two decades or more. Material and coating decide whether it corrodes, and orientation and tilt decide how much the panels generate at all. A structure specified for the site (its wind exposure, its roof type, its latitude) is doing more for long-term output than most of the components people compare more carefully.

They decide how much of the available sunlight actually reaches the cells. In India, a south-facing array tilted close to the site’s latitude captures the most annual energy; a north-facing roof or a flat, un-tilted layout gives up a meaningful share of that. A survey checks orientation before anything is designed, because it can change what is worth installing at all, not just how well it performs.

Yes. Panels are rated at a standard 25°C test temperature, and output falls as the panel itself gets hotter — crystalline silicon panels typically lose somewhere around 0.3–0.4% of output per °C above that. On a 45°C+ day in Vijayawada or Guntur the panel surface runs well above ambient, so peak summer sun generates slightly less per panel than the same sunlight would on a cooler day. It is one reason annual generation is planned as a yearly average rather than a single hot-day figure.