Gross metering is a mechanism in which the entire energy generated by your solar system is exported to the grid at a certain rate. In this case, the energy generated from your system is not consumed by you in any capacity. Once the energy is generated from your solar system it is transferred to the grid, and the grid further sells the energy to the power consumers at a certain tariff rate.
Gross-metering is often confused to be a synonym of net-metering. However, it is not. In the case of net-metering, the power generated by the solar system is first used for self-consumption and if there is any leftover surplus energy, only then it is transferred to the grid in exchange for compensation. Net-metering requires installing of a bi-directional meter because in net-metering both the import and export of energy is taken into account to calculate the net consumption of electricity. But in the case of gross-metering, a unidirectional meter is installed to track the total export of electricity from the solar system to the grid.
Gross metering makes sense for those property owners who have idle space and don’t need to generate solar power for their own consumption. They can install a solar system to utilise the idle space and export the entire generated energy to the grid in exchange for financial benefit.