Choose the operating mode first
String on-grid
Efficient and cost-effective. No backup during a grid failure.
Hybrid
Works with compatible batteries and backup circuits. Higher cost and design effort.
Microinverter
Module-level conversion can help complex roofs. Check service access and local support.
DC panel capacity and AC inverter capacity can differ
Installers sometimes use a solar array slightly larger than the inverter’s AC rating. This can improve output in lower-light hours, though it can also clip peak power. The right ratio depends on local weather, orientation, inverter limits and warranty terms.
Never exceed the inverter’s allowed input voltage or current. Also match single-phase or three-phase supply and your DISCOM’s connection rules.
MPPTs help with different roof faces
A maximum power point tracker manages a group of modules. Roof sections facing different directions or receiving different shade should not be combined without a suitable design. Ask the vendor to show which panels connect to each MPPT.
Details to put in the quote
- Make and exact model
- Rated AC power and maximum DC input
- Number and operating range of MPPTs
- Single-phase or three-phase output
- Ingress protection and installation location
- Monitoring access and data ownership
- Product warranty and local service route
- Anti-islanding and required grid protections
Keep the inverter out of harsh direct sun and water unless the manufacturer permits that location. Accessible installation makes inspection and service easier.
Common questions
Is a 3 kW inverter always needed for 3 kW of panels?
Not always. Designers can use a different DC to AC ratio within the inverter limits and applicable rules. Ask for the expected clipping and annual generation effect.
Can I add a battery to any on-grid inverter later?
Usually not directly. Some systems need a separate battery inverter or replacement with a hybrid model. Plan the upgrade path before purchase.
Official sources
Rules and portal processes can change. Check these sources before committing money.