What is Net Metering?

Net Metering is an electricity policy for utility customers who operate their own on-site "self-generation" power systems such as photovoltaic systems. PV systems are connected to the utility grid via the customers' main service panel and meter and, when generating more power than is needed at the site, return excess electricity to the grid through the power meter, reversing the meter from its usual direction. As a result of the meter working in both directions – one way to measure power purchased (when on-site demand is greater than on-site power production), the other way to measure power returned to the grid – the customer pays the "net" of both transactions.

Net metering is the concept which records net energy between export of generated energy and import of Discom energy for a billing month. Implementation of net metering facility shall be made applicable for the consumers having 3-phase supply service connection. 30% subsidy on the project cost is available from Ministry of New and Renewable Energy, Government of India. The balance cost is to be met by the consumer.

Based on available roof area, solar PV panels will be installed on the roof of the building. The output of the panels (DC electricity) connect to the power conditioning unit / inverter which converts DC to AC. The inverter output will be connected to the control panel or distribution board of the building to utilise the power. The inverter synchronises with grid and also with any backup power source to produce smooth power to power the loads with preference of consuming solar power first. If the solar power is more than the load requirement, the excess power is automatically fed to the grid. For larger capacity systems connection through step up transformer and switch yard may be required to feed the power to grid. There are currently 10 states (Gujarat, united Andhra Pradesh, Telangana, Uttarakhand, Tamil Nadu, West Bengal, Karnataka, Kerala, Delhi and Punjab) that have announced net-metering policies in India. These policies are aimed at encouraging the adoption of distributed solar PV generation in the country.