Kilowatt (kW) vs Kilowatt-hour (kWh)
kW is the power capacity of your system (like the horsepower of a car). kWh is the energy unit you pay for (like the fuel in the tank). A 1 kW system generates about 4-5 kWh (units) of energy per day.
Net Metering
A billing mechanism that allows you to send excess electricity generated by your solar panels back to the grid. You get credits for this export, which are deducted from your bill for the power you consume at night. It effectively uses the grid as a free battery.
Gross Metering
Unlike Net Metering, here you sell ALL generated power to the grid at a fixed rate and buy ALL your consumption from the grid at the normal rate. This is less common now but used in some commercial setups.
On-Grid vs Off-Grid vs Hybrid
- On-Grid: Connected to the utility grid. No batteries. Cheaper. Shuts down during power cuts.
- Off-Grid: Independent system with batteries. Essential for remote areas. Expensive.
- Hybrid: Best of both worlds. Connected to grid but has batteries for backup during power cuts.
Bifacial Panels
Modern panels that generate power from both the front (direct sunlight) and the back (reflected light from the roof). They can increase generation by 10-20% if installed on a reflective surface.
Shadow Analysis
A study done before installation to ensure no shadows from trees or buildings fall on the panels between 9 AM and 4 PM. Even a small shadow can drastically reduce system output.