Solar Grid tied systems are miniature power generating stations connected in parallel to the grid. Solar panels mounted on the roof top generates electricity based on radiation. If the customer uses it directly, then the power from grid will not be drawn, if the customer does not use the electricity, then the power is sent to main grid. This process is called energy export. To calculate the consumption and export,there will be a bi-directional meter to calculate, energy inflow and out flow. The diagram below will illustrate the system in detail,