Solar PV (Photo Voltaic) cells convert sun energy into electrical energy, thus using cleaner way to generate power. Net Metering systems work in perfect sync with Grid power to support the load connected. These systems do not have Battery back-up and consume solar energy generated on-line & excess generated electricity units will get banked in to the grid. Net metering is a billing mechanism that credits solar energy system owners for the electricity they add to the grid.
Typical ROI is up to 4 years & system life is of 25 years.